PSFVIP13

The 13th Pacific Symposium on Flow Visualization and Image Processing
August 7 - 10, 2022
Kogakuin University, Shinjuku, Tokyo, Japan

Program Book

Organized by Pacific Center of Thermal Fluids Engineering (PCTFE),
Visualization Society of Japan (VSJ) and Kogakuin University

Cooperated by JSME, HTSJ, GMSIContents

Welcome Address…………………………………………………………..……...3
PSFVIP13 Committees……………………………………………………………4Timetable…………………………………………………….……………….……7
Plenary Lectures…………………………………………………………………...8
Program Details.......…...………………………………………………………….11
Floor Map………………………………….……………………………………...18
Kogakuin University Access……………………………………………………...20
Park Hyatt Tokyo Access ……..…………..……………………………………...21
Abstracts………………………………………………………………………….22

Welcome Address
Welcome to the PSFVIP13, The 13th Pacific Symposium on Flow Visualization andImage Processing. PSFVIP13 is organized by Pacific Center of Thermal Fluids Engineering(PCTFE), Visualization Society of Japan (VSJ) and Kogakuin University, cooperating by The
Japan Society for Mechanical Engineers (JSME), The Heat Transfer Society of Japan (HTSJ)
and GMSI, The University of Tokyo.
The objective of this symposium is to provide an opportunity for world-wide
researches and engineers in all areas of flow visualization, image processing and related
techniques to exchange knowledge and new experience in the spirit of collaboration andfriendship. Papers dealing with current research ranging from fundamental principles andtechniques to applications on the above topics are appropriate. Topics include, but are notlimited to, flow field visualization, surface flow visualization, computer assisted techniques,graphical display of data, digital image processing and CFD studies.
PSFVIP13 is held at the same time and venue as the 50th Anniversary Symposiumof Visualization Society of Japan, and some sessions is held jointly. PSFVIP13 offers a hybrid
type of symposium that combines face-to-face and online modes. The "online type" will be able
to respond to the situation of Covid-19, and people from overseas and other distant places will
be able to participate easily. In the “face-to-face format”, participants will be able to have indepth discussions with each other. We hope the symposium will be a wonderful experience forall participants.
Chair of PSFVIP13

Yasuyuki Yokono
Senior Researcher
School of Engineering
The University of Tokyo

Satoshi Someya
Duputy Director
Research Institute for Energy Conservation
National Institute of Advanced
Industrial Science and Technology

PSFVIP13 Committees
Symposium Chair
Yokono, Yasuyuki
Someya, Satoshi

The University of Tokyo
AIST

Japan
Japan

Secretary General
Funatani, Shumpei

University of Yamanashi

Japan

PCTFE President
Ishizuka, Masaru

Toyama Prefectural University

Japan

AdvisorMochizuki, Sadanari

Tokyo University of Agriculture and Technology

Japan

Executive Committee
Baba, Kazutaka
Fukue, Takashi
Fushinobu, Kazuyoshi
Hatakeyama, Tomoyuki
Hiratsuka, Masaki
Ito, Shinichiro
Kawaguchi, Tatsuya
Kibushi, Risako
Koizumi, Katsuhiro
Komiya, Atsuki
Konda, Kazuko
Kubota, Yoshihiro
Li, Yanrong
Matsuda, Yu
Nakai, Kumi
Nishi, Koji
Nonomura, Taku
Saitoh, Hironori
Torii, Shuichi
Tsubokura, Makoto
Yamagata, Takayuki
Yuki, Kazuhisa

JP-DOT.COM Co. Ltd.
Kanazawa Institute of Technology
Tokyo Institute of Technology
Toyama Prefectural University
Kogakuin University
Kogakuin University
Tokyo Institute of Technology
Toyama Prefectural University
Nabtesco R&D Center
Tohoku University
The University of Tokyo
Toyo University
Ibaraki University
Waseda University
AIST
Ashikaga University
Tohoku University
Sojo University
Kumamoto University
Kobe University
Niigata University
Tokyo University of Science at Yamaguchi

Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan

Symposium Secretariat
GMSI Office

The University of TokyoJapan

Honorary Committee
Ay, H
National Kauohsiung Unversity of Applied Sciences
Brynjolfsson, S.
University of Iceland
Cardone, G
University of Naples
Carlomagno, G.M.
Univ. of Napoles
Cervantes de Gortari,J. National Univ. of Mexico
Chan, S. H.
Yuan Ze University
Chinda Charoenphonphanich
KMITL
De Vahl Davis, G.
Univ. of New South Wales
Dincer, I.
University of Ontario Institute of Technology
Djilali, N.
University of Victoria
Dost, S.
University of Victoria
Hanamura, K.
Tokyo Institute of Technology
Iguchi, M.
Hokkaido University
Inoue, M.
Komatsu
Jezek, J.
Czech Technical University in Prague
Kobayashi, T.
JARI

TaiwanIcelandItaly
Italy
MexicoTaiwanThailandAustralia
CanadaCanadaCanada
Japan
Japan
Japan
Czech
Japan

Kompenhans, J.
Lee, J. S.
Lee, S. Y.
Liou, T.M.
Mallinson, G.
Merzkirch, W.
Mochizuki, S
Milton, B.
Prenel, J. P.
Raupenstrauch, H.
Sang Joon Lee
Settles, G.S.
Spitas, C
Suzuki, K
Takeishi, K. T
Wang, B. X.
Winoto, S. H.
YanuarYoo, J.Y.
Znamenskaya Irina
Zuna, P.

DLR
Seoul National University
KAIST
National Tsing Hua University
University of Auckland
Univ. Essen
Tokyo University of A & M
University of New South WalesFranche-Comte University
Montan University
POSTECH
Penn State University
Delft University of Technology
Tokyo University of Science at Yamaguchi
okushima Bunri Univesity
Tsinghua University
National University of Singapore
University of Indonesia
Seoul National University
Lomonosov Moscow State University
Czech Technical University in Prague

International Scientific Committee
Akoshima, Megumi
AIST
Asano, Hitoshi
Kobe University
Cardone, Gennaro
University of Napoles
Carlomagno, G.M.
Univ. of Napoles
Cater, J.
University of Auckland
Choi, Chang Kyoung Michigan Technology University
Fujisawa, Nobuyuki
Niigata University
Fukue, Takashi
Kanazawa Institute of Technology
Fumoto, Koji
Hirosaki University
Hirasawa, Shigeki
Kobe University
Hirata, Katsuya
Doshisha University
Hirose, Koichi
Iwate University
Hirota, Masafumi
Mie University
Hishida, Koichi
Keio University
Hong, C. W.
National Tsing Hua University
Hu, Hui
Iowa State University
Ichimiya, Koichi
University of Yamanashi
Ipposhi, Shigetoshi
Mitsubishi Electric Co.Ltd.
Itaya, Yoshinori
Gifu University
Iwai, Hiroshi
Kyoto University
Joshi, Y.
Georgia Institute of Technology
Kaewpradap, A.
King Mongkut's University of Technology Thonburi
Kano, Ichiro
Yamagata University
Katoh, Yasuo
Yamaguchi University
Kawanami, Tsuyoshi Kobe University
Kedzierski, M.
National Institute of Standards and Technology
Kuzma-Kichta, Y. A. Moscow Power Eng. Institute
Kihm, Kenneth D.
University of Tennessee
Kim, H. D.
Andong National University
Kim, K. C.
Pusan National University
Komiya, Atsuki
Tohoku University
Komiyama, Masaharu Gifu University
Kunugi, Tomoaki
Kyoto University
Lee, S. J.
Pohang University of Science and Technology
Li, H.Y.
Huafan University
Liou, Tong-Miin
National Thing Hua University
LIU, Yingzheng
Shanghai Jiaotong University
Maekawa, Hiroshi
The University of Electro-Communications
Markovich, Dmitry
Kutateladze Institute of Thermophysics

Germany
Korea
Korea
TaiwanNew ZealandGermanyJapan
Australia
FranceAustria
Korea
USA
Netherlands
Japan
Japan
China
Singapore
Indonesia
Korea
Russia
Czech

Japan
Japan
Italy
Italy
New Zealand
USA
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Taiwan
USA
Japan
Japan
Japan
Japan
USA
Thailand
Japan
Japan
Japan
USA
Russia
USA
Korea
Korea
Japan
Japan
Japan
Korea
TaiwanTaiwanChina
Japan
RussiaMaruyama, Shigenao Tohoku University
Matsumoto, Mitsuhiro Kyoto University
Matsumoto, Ryosuke Kansai University
Matsushima, Hitoshi
Nihon University
Mosharov, Vladimir
Moscow University Physics and Technology
Motosuke, Masahiro
Tokyo University of Science
Munakata, Tetsuo
AIST
Murata, Akira
Tokyo University of Agriculture and Technology
Nagai, Niro
University of Fukui
Nagasaki, Takao
Tokyo Institute of Technology
Nakabe, Kazuyoshi
Kyoto University
Nakamura, Hajime
National Defense Academy
Nakamura, Yuji
Toyohashi University of Technology
Ng, Eddie
Nanyang Technical University
Nishi, Koji
NIDEC CORPORATION Japan
Nishida, Keiya
Hiroshima University
Oda, Yutaka
Kansai University
Ohmi, Kazuo
Osaka Sangyo University
Ohara, Taku
Tohoku University
Okajima, Junnosuke
Tohoku University
Okuyama, Masaaki
Yamagata University
Oomura, Takahiro
National Institute of Technology, Wakayama College
Ozawa, Mamoru
Kansai University
Paeng, D. G.
Jeju Water Industry Center
Riznic, J.
Canadian Nuclear Safety Commission
Rosengarten, G.
University of New South Wales
Roy, R.P.
Arizona State University
Saito, Takushi
Tokyo Institute of Technology
Senaha, Izuru
Ryukyu University
Shibahara, Masahiko Osaka University
Shiomi, Junichiro
The University of Tokyo
Someya, Satoshi
AIST
Suzuki, Hiroshi
Kobe University
Tabe, Yutaka Hokkaido University
Tagawa, Masato
Nagoya Institute of Technology
Taguchi, Yoshihiro
Keio University
Takei, Masahiro
Chiba University
Tong, Albert Y.
University of Texas at Arlington
Tsushima, Shoji
Osaka University
Yamada, Shunsuke
National Defense Academy
Yamashiro, Hikaru
National Institute of Technology, Okinawa College
Yasuhara, Caoru
Yamagata University
Yang, C. Y.
National Central University
Yan, W.M.
National Taipei University of Technology
Yazawa, Kazuaki
Purdue University
Yeh, L-T
Huawei Technologies
Yokono, Yasuyuki
The University of Tokyo
Yuuki, Kazuhisa
Tokyo University of Science, Yamaguchi
Zhu, Ning
Shizuoka Institute of Science and Technology

Japan
Japan
Japan
Japan
Russia
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Singapore
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Korea
CanadaAustralia
USA
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
Japan
USA
Japan
Japan
Japan
Japan
TaiwanTaiwan
USA
USA
Japan
Japan
Japan

Timetable
PSFVIP13 Timetable (As is 2022.7.28)
Aug. 7

Aug. 89:00-10:00

Registration

Aug. 99:00-9:40

Plenary Lecture II (Room A)
Professor Han Seo Ko

9:50-10:30

VSJ Memorial Plenary Lecture 2

10:20-11:50 Registration
10:40-11:40 VSJ Memorial Panel Session
Opening (Room A)
13:00-13:50 Plenary Lecture I (Room A)
Professor Jan A.Stasiek
14:00-14:40 VSJ Memorial Plenary Lecture 1

Technical Sessions 3 (5)Room F,G,H,I,E
F(OS6) 33, 48, 54, 100, 61
13:00-14:40 G(OS2) 44, 46, 56, 74, 84
H(OS1(VSJ OS3)) J4, J9, J17, J29
I(GS13) 14, 41, 50, 69, 80
E(OS9) 12, 21, 22, 26, 30

Technical Sessions 1 (4)Room F,G,H,I,E
F(OS5) 6, 28, 68
15:00-16:20 G(OS4) 24, 47, 97, 98
H(OS1) 88, 89, 105, 106
I(GS15) 110, 64, 65, 95
E(OS8) 4, 13, 16, 19

Technical Sessions 4 (4)Room F,G,H,I,E
F(OS7) 29, 17, 34, 7
15:00-16:20 G(OS2 (VSJ OS2)) J33, J36, J69, J88
H(OS1) 51, 77, 109, 108
I(GS2) 2, 23, 37, 101
E(OS8) 83, 60, 114, 39

16:00-17:00 Registration

Technical Sessions 2 (4)Room G,H,I,E
G(OS4) 35, 102, 107
16:40-18:00
H(OS1) 62, 79, 87, 113
I(GS15) 45, 66, 70, 73
E(OS8) 9, 20, 31, 11

Technical Sessions 5 (4)Room F,G,H,E
F(OS7) 52, 63, 104, 49
16:40-18:00
G(OS2 (VSJ OS2)) J34, J57, J70
H(OS1(VSJ OS3)) J28, J32, J50
E(OS8 (VSJ OS7)) J39, J73, J74, J75

17:00-18:00 Welcome Reception

18:30-20:00 PSFVIP13 Symposium Dinner

18:30-20:00 VSJ Bnquet

Aug. 10
9:00-9:40

Plenary Lecture III (Room A)
Professor Nobuyuki Oshima

Technical Sessions 6 (6)Room F,G,H,I
F(GS7) 3, 25, 53, 57, 76, 78
10:00-12:00
G(GS6) 86, 32, 55, 58, 75
H(OS3(VSJ OS6)) J63, J68, J85, J90
I(GS2) 8, 10, 111, 18, 90, 99

Technical Sessions 7 (6)Room F,G,H
13:00-15:00 F(GS7) 59, 93, 94, 96, 5
G(GS4) 43, 67, 72, 85, 91
H(OS3) 124, 119, 120, 121, 122, 123
RED: joint session with VSJ

PSFVIP13 offers a hybrid type of symposium that combines face-to-face and online modes.
Online will be by "Zoom."
Room URL and the proceedings password are informed to the registered participants by e-mail.
Eduroam is available in the symposium site.
Plenary Lectures: 35minutes talk, 5minutes Q/ATechnical sessions: 15minutes talk, 3minutes Q/APlenary Lectures
Professor Jan A. Stasiek
Professor, Gdansk University of Technology, Poland

Liquid crystal thermography as a modern and unique tool
for technical and scientific research

The beginning of the 21st century is marked by the years of intensive research and developmentwith micro- and nanotechnology, highly effective energy conversion technology and methodsof reducing its impact on environmental degradation. Scientific researchers dealing with heatand mass transfer must face new challenges in the design and construction of modern and highly
efficient processes, devices and apparatus. Designers of thermal devices expect, for example,
more detailed information on the local values of the heat transfer coefficient, without limiting
to its averaged values. These expectations are met by automated and fully computerized liquid
crystal thermography (LCT) based on physico-chemical properties, among others: cholesterolesters (with a helicoids structure) as well as colour digital images processing. It allows not only
to study complex geometries or the influence of inhomogeneous boundary conditions, but also
pulsatile and turbulent flows of large scales and low frequencies. Phenomena characterized bysuch a complex heat transfer can be found in most devices where energy conversion processes
take place. Furthermore, liquid crystal thermography (LCT) assisted by particle image
velocimetry (PIV) and digital image processing (DIP) is an excellent and recognizedmeasurement method used in the study of advanced thermal-flow processes and in major worldwide research centres. Theoretically, LCT enables the visualization of two-dimensionaltemperature and velocity fields with an accuracy of one pixel and identifying the influence ofmany thermo-physical and flow factors on the formation of a laminar and turbulent boundary
layer. Therefore ,in the plenary lecture, the history of LCT techniques will be reviewed and theprincipal methods are described, using examples from current literature and own research.

Professor Han Seo Ko
Professor School of Mechanical Engineering,
Sungkyunkwan University, Korea.

Practice Your Scales! Nanomaterials for Fast Energy
Processes

The interaction between electrostatic and hydrodynamic phenomena was analyzed by adopting
advanced techniques for numerical simulation and flow visualization. Rising bubbles inside a
conductive medium can affect formation of electric field. The current varies depending on theoccupation of non-conductive volume, and local electric signals can be interpreted as dispersed
phase. Interesting influence between different physics can be applied to the study on a wiremesh sensor (WMS) which is used to measure the characteristics of the multiphase flow.
Electrohydrodynamic (EHD) flow is a promising field, especially for gas pumping applications.
The EHD flow can be produced by the formation of non-thermal plasma (NTP) on a surface
with high curvature. In this study, an analytical model was employed, and the experiment was
carried out with the configuration of a wire and two cylinders in an open space. The Townsend
relation between electric signals was checked for the stable generation of corona discharge, andthe empirical equation was employed to verify the relation between parameters, such as current,
voltage, and momentum. The cooling performance of the EHD flow was evaluated bycomparison with the heat transfer coefficient of natural convection. The heat transfer coefficientand Nusselt number were calculated, and their correlation could be obtained.

Professor Nobuyuki Oshima
Professor, Division of Mechanical and Aerospace Engineering
Faculty of Engineering, Hokkaido university

Be Ambitious ! to use Open-source software for CFD andflow visualization

Recently, useful open-source software are published for CFD and related simulations. They arewidely applied to varieties of physical and engineering problems, which are operated bydifference scale computers, from notebook PC to supercomputer “FUGAKU”. As an entranceof “Open-source CFD”, a few results of major software as OpenFOAM, SU2, FrontFlow andtheir coupling software are introduced for the applications to bubble flow in turbulent boundary
layer, flow-structure interaction of artery flow, and spray/combustion flow in gas-turbine, etc.
These examples will make researchers, scientists and engineers “Be Ambitious !” to use Opensource CFD and flow visualization.
On the other hand, open-source CFD still has merits and demerits to develop, to distribute andto use, as compared to other ways by commercial software and/or unpublished special-maid
ones, though the recent development of computers and networks brings much easier access torequired data and information. Shall we discuss how to support such open-source world in CFD
and visualization?

Program Details
Day1
JST(UTC+9)09:00-10:00
JST(UTC+9)10:20-11:50

JST(UTC+9) Aug.8
13:00-13:50

JST(UTC+9)14:00-14:40

joint session with VSJ
JST(UTC+9) Aug.8, 09:00-20:00
Room A
Registration
VSJ Anuual Meeting
Opening remarks
Session Chair: Satoshi Someya ( AIST )Yasuyuki Yokono (The University of Tokyo)
Masaru Ishizuka (PCTFE Japan)
Plenary Lecture I
Session Chair: Sumpei Funatani (Yamanashi University)
Liquid crystal thermography as a modern and unique tool for technical and scientific research
Jan A.Stasiek (Gdansk University of Technology)
VSJ Memorial Plenary Lecture 1 ( in Japanese )Room E
Technical Sessions E1
OS8*: Physiological/Biological fluid dynamics
Session Chair: Kenichi Funamoto(Tohoku University)
4 INVESTIGATION OF THE INFLUENCE OF VASCULAR ACCESS SHAPE ON HEMODYNAMIC PARAMETERS
Hitomi Anzai, Kazuki Takeda, Ai Kajiyama and Makoto Ohta
13 FUNDAMENTAL STUDY OF MR-MEASUREMENT-INTEGRATED SIMULATION OF HEART-AORTA-SYSTEM: APPLICATION TO
AN AORTIC ARCH
Suguru Miyauchi
16 SIMULATION OF A PACKED SUSPENSION OF MICROSWIMMERS
Yu Kogure, Toshihiro Omori and Takuji Ishikawa
19 VISUALIZATION OF FLOW FIELD INDUCED BY HYDRODYNAMIC INTERACTIONS OF SWIMMING MICROORGANISM
Kiyoto Kubo, Toshihiro Omori and Takuji Ishikawa
Room F
Technical Sessions F1
OS5: Thermal management of electronics
Session Chair: Katsuya Hirata(Doshisha University )6 START-UP CHARACTERISTICS OF LOOP HEAT PIPE WITH PLATE-TYPE EVAPORATOR
Tomohiro Nakazawa, Atsushi Tsujimori, Tsubasa Usui, Koji Ono, Reo Miwa, Norifumi Miyanaga, Yui Sato and Haruka Suzuki
28 Visualization of Thermal Networks in Layered Structures by Means of Pump-Probe and Deconvolution Technique
Joao Vitor Thomsen Silveira, Daiki Higuma and Kazuyoshi Fushinobu
68 INFLUENCE ON THERMAL IMPEDANCE ALONG HEAT TRANSFER PATH OF POWER SEMICONDUCTOR PACKAGE BY
COPPER PAD ON PRINTED CIRCUIT BOARD
Koji Nishi
Room G
Technical Sessions G1
OS4: Combustion and Reacting Flow
Session Chair: Chihiro Kondo(Okayama University of Science)

JST(UTC+9) Aug.8
15:00-16:20

24 NEAR-LIMITING BEHAVIOR OF POOL FIRES WITH STRONG SWIRLING FLOW
Keita Tsukamoto, Akira Odawara, Takuya Yamazaki, Tsuneyoshi Matsuoka and Yuji Nakamura
47 INFLUENCE OF THE THIRD STREAM TO A THREE-FEED NON-PREMIXED COMBUSTION SYSTEM
Sujeet Yadav, Panlong Yu and Hiroaki Watanabe
97 NUMERICAL ANALYSIS ON THE TEMPERATURE OF AN ETHANOL SPRAY IN ITS MIXTURE FORMATION PROCESS UNDERDIESEL ENGINE OPERATING CONDITIONS
Hironori Saitoh and Hikaru Tsunoda
98 MICROSCOPIC IMAGE DIAGNOSTICS WITH VISIBLE EMISSION LIGHT FOR SELF-BURNING SURFACE TEMPERATURE
DISTRIBUTION OF CFRP (CARBON FIBER REINFORCED PLASTIC) IN OXYGEN
Yojiro Ishino and Rion Ito
Room HTechnical Sessions H1
OS1*: Luminescence-based Flow Measurement for Thermofluid Analysis
Session Chair: Hideo Mori(Kyushu University)
88 Unsteady pressure distribution measurement on cylinder surface using anodized aluminum pressure-sensitive paint during shock
wave passage
Shintaro Tamakuma, Kazuma Yomo, Toshihiro Ogawa and Hiroki Nagai
89 Development of pressure distribution measurement technology on free-flight object surface at transonic speed
Yota Hosono, Kazuma Yomo, Koichi Takahashi, Toshihiro Ogawa, Kiyonobu Ohtani and Hiroki Nagai
105 Evaluation of pressure distribution around small rotor blade in low oxygen partial pressure region using PSP
Kousei Ogawa, Yanrong Li, Satoshi Someya, Terumi Inagaki, Shimpei Saito, Soumei Baba and Naoki Takada
106 NOISE SUPPRESSION METHOD FOR PSP DATA BASED ON REDUCED-ORDER MODELING
Tomoki Inoue, Yu Matsuda, Tsubasa Ikami, Taku Nonomura, Yasuhiro Egami and Hiroki Nagai
Room I
Technical Sessions I1
GS15: Classical and advanced measurement
Session Chair: Hajime Nakamura(National Defense Academy)
110 IMPROVEMENT OF SPATIAL RESOLUTION OF HIGH-SPEED-BACKGROUND-ORIENTED SCHLIEEN THROUGHATOMOSPHERIC TURBULENCE
Toshiharu Mizukaki, Miyuki Kondo and Takeo Minezaki
64 THREE-DIMENTIONAL DENSYTY MEASUREMENT USING SIMULTANEOUS MULTI-ANGLE BOS MEASUREMENT SYSTEM IN A
SUPERSONIC WIND TUNNEL
Masato Yamagishi, Yusuke Hirose, Shinsuke Udagawa, Tatsuro Inage and Masanori Ota
65 HIGH ACCURATE DENSITY MEASUREMENT OF TRANSONIC FLOW FIELD AROUND THE REENTRY CAPSULE MODEL
Yutaro Katagiri, Nao Kosaka, Masato Yamagishi, Yusuke Hirose, Masanori Ota, Masayuki Nomura, Koji Hujita, Kiyonobu Kiyota andHiroki Nagai
95 IMPROVEMENT IN ACCURACY OF THE BACKGROUND ORIENTED SCHLIEREN TECHNIQUE WITH PARALLEL PROJECTION
Nao Kosaka, Yuto Igari, Yutaro Katagiri, Masato Yamagishi and Masanori Ota
joint session with VSJ

Day1

joint session with VSJ
Room E
Technical Sessions E2
OS8*: Physiological/Biological fluid dynamics
Session Chair: Hitomi Anzai (Tohoku University)
9 COMPARISON OF HEMODYNAMICS IN LEFT VENTRICLES WITH TRICUSPID AORTIC VALVE AND BICUSPID AORTICVALVES
Shingo Tsuda, Suguru Miyauchi and Kenichi Funamoto
20 MODELING SPERM SUSPENSION IN THREE DIMENSIONS
Nanami Taketoshi, Toshihiro Omori and Takuji Ishikawa
31 VISUALIZATION OF A FRESHWATER-SPONGE SNEEZING
Kei Kawashima, Kenji Kikuchi and Takuji Ishikawa
11 COMPUTATIONAL MODELING OF THE SPONGEʼS CHOANOCYTE CHAMBER
Takumi Ogawa, Toshihiro Omori, Kenji Kikuchi and Takuji Ishikawa
Room G
Technical Sessions G2
OS4: Combustion and Reacting Flow
Session Chair:Hironori Saitoh( Sojo University)
35 INERT GAS FLOW RELEASED FROM BURSTING SAUSAGE-SHAPED RUBBER BALLOON AND ITS EXTINGUISHING
CHARACTARISTICS
Hinako Mikami and Hiroyuki Torikai
102 Simultaneous measurement of gaseous flow and spark channel using inexpensive inorganic fluorescent tracer
Chihiro Kondo and Masanobu Yoshioka
107 SCHLIEREN VISUALIZATION OF EXTINGUISHING PROCESS OF DIFFUSION FLAMES IN AIRBURST BLAST
EXTINGUISHMENT WITH MICRO EXPLOSIVES
Yuma Yoshida and Hiroyuki Torikai

JST(UTC+9) Aug.8
16:40-18:00

Room HTechnical Sessions H2
OS1*: Luminescence-based Flow Measurement for Thermofluid Analysis
Session Chair: K.C.Kim(Pusan National University)
62 Dependence of measurement accuracy and time delay of lifetime-based dual-layer PSP/TSP on film thickness
Hideo Mori, Takamitsu Kuroki and Haruka Nishiyama
79 Frequency Response of Carbon-nanotube Temperature-sensitive Paint
Tsubasa Ikami, Koichi Takahashi, Yasufumi Konishi and Hiroki Nagai
87 Development of visualization technique for hydrodynamic stress field utilizing fluorescent force probe
Reiko Kuriyama, Ryohei Okamoto, Waka Yamamoto, Hidetsugu Kitakado, Shohei Saito, Kazuya Tatsumi and Kazuyoshi
Nakabe113 DEVELOPMENT OF TEMPERATURE MEASUREMENT SYSTEM OF AIRFLOW USING ULTRA-FINE THERMOSENSITIVELUMISIS PHOSPHOR WIRE
Yu Morito and Shumpei Funatani
Room I
Technical Sessions I2
GS15: Classical and advanced measurement
Session Chair: Masanori Ota(Chiba University)
45 EVALUATION OF THE INFLUENCE OF READING PIXEL IN THE DRAG COEFFICIENT CALUCULATED FROM HIGH-SPEED
VIDEO CAMERA IMAGES
Tomohiro Miyazaki, Takamasa Kikuchi and Akinori Muramatsu
66 Ultrasound Vector Projectile Imaging of Urinary Flow Dynamics
Takuro Ishii
70 STUDY ON DRAG COEFFICIENT FOR CIRCULAR PLATE WITH HOLES
Kazuki Namba, Yoshihiro Kubota and Osamu Mochizuki
73 Visualization of Shock waves above water driven by water entry using shadow graph method
Yusuke Ebii, Takamasa Kikuchi and Akinori Muramatsu

JST(UTC+9)18:30-21:00

PSFVIP13 Symposium Dinner

Day2

JST(UTC+9) Aug.9
09:00-09:40

JST(UTC+9)09:50-10:30
JST(UTC+9)10:40-11:40

JST(UTC+9) Aug.9, 09:00-20:00
Room A
Plenary Lecture Ⅱ

joint session with VSJ

Session Chair: Satoshi Someya ( AIST )Analysis of multi-phase and electrohydrodynamic (EHD) flow for convective heat transfer using visualization technique
Han Seo Ko (Sungkyunkwan University)
VSJ Memorial Plenary Lecture 2 ( in Japanese )VSJ Memorial Panel Session ( in Japanese )Room E
Technical Sessions E3
OS9*: Wavelets and Flow Control
Session Chair: Yoshiki Niizeki(Tokushima-Bunri University)
12 Multiscale flow structures in a cube wake influenced by the front inclined hole
Jiawei Li, Xiaolei Han, Hiroka Rinoshika and Akira Rinoshika
21 Experimental study of moving-TRPIV on drag reduction control of coherent structures in turbulent boundary layer oversuperhydrophobic surface
Yue Jinhui, Wang Xinwei and Jiang Nan
22 Tomographic PIV measurements in the wake of a wall-mounted barchan dune
Xiaolei Han and Akira Rinoshika
26 3D WAVELET TRANSFORM ON FLOW STRUCTURES BEHIND A WALL-MOUNTED SHORT CYLINDER WITH A FRONTINCLINED HOLE
Hiroka Rinoshika
30 EXPERIMENTAL INVESTIGATION ON FLOW CHARACTERISTICS AND HEAT TRANSFER OF NONCIRCULAR SYNTHETICJETSLei Wang, Lihao Feng, Yang Xu and Jinjun Wang
Room F
Technical Sessions F3
OS6: Visualization-based Advanced Flow Measurement and Control
Session Chair: Kumi Nakai(National Institute of Advanced Industrial Science and Technology)
33 STUDY OF UNDEREXPANDED SUPERSONIC JETS FROM AXISYMMETRIC MICRO-NOZZLES IN LOW REYNOLDS NUMBERREGIONS
Tenta Tashiro, Sinichiro Nakao and Yoshiaki Miyazato
48 SPATIAL SUPERRESOLUTION BASED ON PROPER ORTHORGONAL DECOMPOSITION AND BAYSIEN ESTIMATION OF
SUBSONIC JET FLOW MEASURED BY TWO MAGNIFICATION PIV SIMULTANEOUS MEASUREMENT
Honda Harutaka, Yuta Ozawa and Taku Nonomura
54 A TIME-RESOLVED THREE-DIMENSIONAL DENSITY MEASUREMENT FOR AN ASYMMETRICAL UNSTEADY SUPERSONIC
IMPINGING JET USING A FIBRE BOS TECHNIQUE
Takuma Kuroda, Masahiro Kobayashi and Takahiro Ukai
100 RESOLUTION ENHANCEMENT BY THE EDSR METHOD FOR BOS ANALYSES
Katsunari Ota and Takahiro Ukai
61 Improvement of Robustness on Real-time Flow Field Measurement using Sparse Processing PIV
Chihaya Abe, Naoki Kanda, Sayumi Kaneko, Kumi Nakai and Taku Nonomura
Room G
Technical Sessions G3
OS2*: Measurement Technique Noninvasive Measurement Technique
Session Chair: Jun Sakakibara(Meiji University)

JST(UTC+9) Aug.9
13:00-14:40

44 COLOR PIV FOR MEASURING THREE-DIMENSIONAL WAKE STRUCTURES OF A DELTA WING FROM 0 TO 90 DEGREE IN
ANGLE OF ATTACK
Kokoro Ochi, Yasufumi Horimoto, Hyun Jin Park, Yuji Tasaka and Yuichi Murai
46 EXPERIMENTAL INVESTIGATION OF SHEAR-INDUCED BIREFRINGENCE PROPERTIES OF RHEOSCOPIC FLUIDS FOR
VISUALIZATION OF STRESS FIELD OF FLUID FLOW
Kosei Hayashi, Shuntaro Tanaka and Katsuaki Shirai
56 Improvement of particle tracking velocimetry with deep learning
Taishi Yano and Yuji Nakanishi
74 DEVELOPMENT OF HIGH-RESOLUTION PSV USING CODED ILLUMINATION AND FEATURE MATCHING ALGORITHM
Yusaku Tsukamoto and Shumpei Funatani
84 Time-resolved PIV Measurements of Flow Field around a Badminton Shuttlecock during Turnover Process
Yuki Sakurai, Kenichi Nakagawa and Hiroaki Hasegawa
Room HTechnical Sessions H3 ( in Japanese )OS1*(VSJ OS3): Luminescence-based Flow Measurement for Thermofluid Analysis
Session Chair: Kazunori Mitsuo(JAXA)
J4 Development of a white screen layer using a water-soluble polymer suitable for fast-responding pressure-sensitive paint
Hiromu Horie, Miku Yamazaki, Yushi Matsumura and Yasuhiro Egami
J9 Quantitative study of property changes due to interference between dyes in mixed-type two-color PSPs
Yushi Matsumura, Yuki Ishida, Takumi Inayoshi, Hiromu Horie and Yasuhiro Egami
J17 Progress of Simultaneous Measurement of Pressure and Temperature Fields by DL-PTSP Applying Lifetime-Based Calibration
MethodTakamitsu Kuroki, Haruka Nishiyama and Hideo Mori
J29 Unsteady Measurement of Back Flow Induced by Surging Caused by Transonic Centrifugal Compressor Using DL-PTSP
Masashi Yoshikawa, Kodai Tsuji, Hideo Mori and Masato Furukawa
Room I
Technical Sessions I3
GS13: Heat transfer and combustion
Session Chair: Atsuki Komiya(Tohoku University)
14 TIME-RESOLVED VISUALIZATION OF HEAT FLUXES FROM NEAR-WALL TURBULENT FLOWS
Irina Znamenskaya, Ekaterina Koroteeva, and Vladimir Chirich
41 Flow Boiling Heat Transfer in a Plate Heat Exchanger with Mixed Chevron Angle Plates
Mu-Ting Hsieh, Chien-Yuh Yang and Fu-Chen Lin
50 VISUALIZATION OF TRANSIENT HEAT TRANSFER BY A DROPLET BOUNCING ON A HEATED SURFACE VIA
THERMOGRAPHY
Masaki Yoshida, Shunsuke Yamada, Yuki Funami and Hajime Nakamura
69 EXPERIMENTAL STUDY OF THERMAL CONVECTION BY HEATING AND COOLING THE SIDE OR TOP SURFACE OF AROTATING CYLINDRICAL VESSEL
Kohei Shimoura, Tatsunori Ihara, Takashi Noguchi and Katsuya Hirata
80 LOCAL AND TRANSIENT HEAT TRANSFER MEASUREMENT FOR DROPWISE CONDENSATION USING TEMPERATURESENSITIVE PAINTS
Kohei Matsushima, Tomoya Uchimura, and Yutaku Kita

Day2
Room E
Technical Sessions E4
OS8*: Physiological/Biological fluid dynamics
Session Chair: Yoshihiro Kubota (Toyo University)

joint session with VSJ

83 VIDEO ANALYSIS ABOUT THE GLIMMER SYNCHRONIZATION OF LUCIOLA PARVULA FIREFLIESShiro Kobayashi, Nao Ninomiya, Masayuki Iigo and Rion Tada
60 Visualization of Bubble Dynamics inside the Proofing Bread Dough using X-ray Microtomography
Kyosuke Kimura, Kenji Kikuchi, Keiko Numayama, Takuji Ishikawa and Taimei Miyagawa
114 Visualization of microbial transport in the gut of a zebrafish larva
Yuta Kikunaga, Kenji Kikuchi, Keiko Numayama-Tsuruta and Takuji Ishikawa
39 INFLUENCE OF THE PERIODIC FLOW ON THE FLOW STRUCTURE AROUND THE ROBOTIC FISH
Maoto Kawano, Yohsuke Tanaka and Yoshitaka Isoda
Room F
Technical Sessions F4
OS7: Pipe flows, channel flows and internal flows
Session Chair: Shumpei Funatani (Yamanashi University)
29 VISUALIZATION OF MIXING AND FLOW STRUCTURE IN BLADE-FREE PLANETARY MIXER WITH FREE SURFACE
Takayuki Yamagata, Kota Sato and Tsubasa Igarashi
17 MASS TRANSFER AND VELOCITY MEASUREMENTS IN T-JUNCTION PIPING SYSTEM
Kazuki Munemura, Kazuki Kawaguchi, Takayuki Yamagata and Ryo Morita
34 NUMERICAL SIMULATION OF MASS TRANSFER AND VELOCITY IN T-JUNCTION PIPING SYSTEM
Masaaki Satake, Shun Watanabe, Ryo Morita and Takayuki Yamagata
7 VISUALIZATION OF INTERMITTENT TURBULENT STRUCTURE IN ECCENTRIC ANNULAR PIPE FLOW
Kohei Yatsushiro, Yasufumi Horimoto and Takahiro Tsukahara
Room G
Technical Sessions G4 ( in Japanese )OS2*(VSJ OS2): Measurement Technique Noninvasive Measurement Technique
Session Chair: Shigeo Hosokawa (Kansai University)

JST(UTC+9) Aug.9
15:00-16:20

J33 Development of local vorticity instrumentation method using stretched film tracer
Yuki Kudo, Shigeru Muraka and Yohsuke Tanaka
J36 Vortex Structure Formed by a Main flow and a Sweeping Jet
Shoma Tanaka and Masaki Fuchiwaki
J69 Time Series image processing for measuring particle size of single droplet atomization
Tokiha Yada, Kyohei Mizuno, Koudai Iwasaki, Kouta Nakata, Makoto Asahara and Takechi Miyasaka
J88 Characteristics of unsteady surface tension convection driven by spot heating of a thin liquid layer
Tiwari Ratnanjali, Shuma Ogawa and Koichi Nishino
Room HTechnical Sessions H4
OS1*: Luminescence-based Flow Measurement for Thermofluid Analysis
Session Chair: Hiroki Nagai(Tohoku University)
51 VISUALIZATION OF TEMPERATURE FIELD IN A CHANNEL BY LASER INDUCED FLUORESCENCE AND TEMPERATURE
DEPENDENCE OF PARTICLE BEHAVIOR IN THE CHANNEL
Kazuki Hirai, Masahiro Yajima, Hideaki Kato and Katsuaki Shirai
77 ADAPTIVE WINDOW TECHNIQUE FOR LIFETIME-BASED TEMPERATURE AND VELOCITY SIMULTANEOUS MEASUREMENTUSING THERMOGRAPHIC PARTICLE TRACKING VELOCIMETRY WITH A SINGLE CAMERATao Cai, Jeongmin Han, Mirae Kim, Juyong Jung, Hyungmin Shin and Kyung Chun Kim
109 A CRYOGENIC TEMPERATURE SENSITIVE PAINT MEASUREMENT USING METAL COMPLEX MATERIALS AND PHOSPHORS~TEMPERATURE SENSITIVITY OF OPTICAL PROPERTIES ~Yanrong Li, Sou Yasuzawa, Satoshi Someya, Shimpei Saito, Soumei Baba and Naoki Takada
108 A CRYOGENIC TEMPERATURE SENSITIVE PAINT MEASUREMENT USING METAL COMPLEX MATERIALS AND PHOSPHORS~TEMPERATURE SENSITIVITY OF OPTICAL PROPERTIES ~Sou Yasuzawa, Satoshi Someya, Yanrong Li, Shimpei Saito, Soumei Baba and Naoki Takada
Room I
Technical Sessions I4
GS2: Multiphase flow (other)
Session Chair: Eiji ISHII(Hitachi Corporation)
2 GAS HYDRATE FORMATION AND DISSOCIATION UNDER STATIC AND DYNAMIC CONDITIONS
Yasuharu Nakajima, Joji Yamamoto, Satoru Takano, Marcio Yamamoto, Masao Ono, Shigeo Kanada and Kazuhisa Otsubo
23 Reversal Motion of the Solid Particles with High Thermal Conductivity in the Solid-dispersed Rayleigh-Bénard Convection
Shi Dai
37 THE FIBER-ORIENTATION OF CELLULOSE NANOFIBER SUSPENSIONS IN A PLANAR EXPANSION FLOW
Akiyoshi Kusano, Akiomi Ushida and Taisuke Sato
101 Free surface flow of concentrated particle suspension in Hele-Shaw cell
Takashi Koshiba and Takehiro Yamamoto

Day2
Room E
Technical Sessions E5 ( in Japanese )OS8* (VSJ OS7): Physiological/Biological fluid dynamics
Session Chair: Kenji Kikuchi (Tohoku University)

joint session with VSJ

J39 Behaviors of a Pair of Vortex Ring Formed by a Flapping Butterfly
Sei Haishi and Masaki Fuchiwaki
J73 Blood flow visualizations with particle image velocimetry and computational fluid dynamics analysis for therapy of cardiovasculardiseases
Shuya Shida, Toru Masuzawa, Masahiro Osa and Makoto Ohta
J74 Perception of Tone Burst Generated by Animals
Kazuki Sugiyama, Yoshihiro Kubota and Osamu Mochizuki
J75 Shape of Water Splash by Object Impinging to Water Surface
Takashi Yasui and Yoshihiro Kubota
Room F
Technical Sessions F5
OS7: Pipe flows, channel flows and internal flows
Session Chair: Takayuki Yamagata(Niigata University)
52 VISUALIZATION-BASED MEASUREMENT OF FLOW VELOCITY IN A MOLDED PIPE WITH MATCHED REFRACTIVE INDEX
Shunya Ishii, Katsuaki Shirai and Sakura Fukushima
63 IMAGE PROCESSING OF FLOW VISUALISATION PICTURES TO DETERMINE THE STRUCTURE OF TRANSITIONALCHANNEL FLOW OF AQUEOUS POLYMER SOLUTIONSTakato Okuda, Xin Song, Sattaya Yimprasert, Per Henrik Alfredsson and Masaharu Matsubara
JST(UTC+9) Aug.9
16:40-18:00

104 EFFECT OF CONTTAINER SIZE ON FLOW STRUCTURE IN A RECTANGULAR CONTAINER INJECTED AIR FROM A SLITNOZZLE
Takuto Ichihara, Takahiro Kiwata, Kuniaki Toyoda, Hiroaki Uchida, Yasuharu Kawamura and Masamichi Tsuji
49 NUMERICAL ANALYSIS OF INTERNAL FLOW IN A SEPARATE HERRINGBONE PLATE HEAT EXCHANGER
Daiki Fujiwara and Shuichi Torii
Room G
Technical Sessions G5 ( in Japanese )OS2*(VSJ OS2): Measurement Technique Noninvasive Measurement Technique
Session Chair: Koichi Nishino(Yokohama National University)
J34 Visualization of die-cast fluid behavior using PIV analysis
Kousuke Ouchi, Yuki Kasiwabara and Yuta Sunami
J57 Visualization of Hydrogen Partial Pressure Distribution by Raman Imaging
Junpei Yamamoto, Chiaki Mizutani, Koji Ogawa, Hironori Ohira, Masashi Maeda and Tsutomu Hosoi
J70 Near-infrared visualization of water vapor distributions in air: flow analysis using a block matching method
Naoto Kakuta and Shintaro Ozawa
Room HTechnical Sessions H5 ( in Japanese )OS1*(VSJ OS3): Luminescence-based Flow Measurement for Thermofluid Analysis
Session Chair: Yasushiro Egami(AITECH)
J24 Effects of Antioxidants on Photodegradation of the Dual-Luminophore Pressure-Sensitive Paint
Kazuki Uchida, Yuta Ozawa, Keisuke Asai and Taku Nonomura
J32 Development for simultaneous mesurement of pressure and temperature using luminescent paint
Maito Kanehiro, Koshiro Tsutsumi, Takuma Moriya, Mizue Munekata and Hiroyuki Yoshikawa
J50 Mathematical optimization processing for pressure-sensitive paint data
Koyo Kubotam Tomoki Inoue, Tsubasa Ikami, Yasuhiro Egami Hiroki Nagai and Yu Matsuda

JST(UTC+9)18:30-20:00

VSJ Banquet

Day3

JST(UTC+9) Aug.10
09:00-9:40

JST(UTC+9) Aug.10, 09:00-15:00
Room A
Plenary Lecture Ⅲ

joint session with VSJ

Session Chair: Satoshi Someya ( AIST )Be Ambitious ! to use Open-source software for CFD and flow visualization
Nobuyuki Oshima (Hokkaido university)
Room F
Technical Sessions F6
GS7: Vortex
Session Chair: Aref Afsharfard(Pusan National University, Ferdowsi University of Mashhad)
3 EXPERIMENTAL STUDY ON VORTEX WIDTH AND HYSTERESIS EFFECT OF THE FLOW BETWEEN TWO ROTATINGCYLINDERS WITH HIGH ASPECT RATIO
Yuki Sugimoto, Tomoki Marumiya, Haruki Inatani, Katsuya Hirata and Takashi Noguchi
25 Unsteady Flow Instability between Two Parallel Circular Plates in Power Generator
Naho Kishizawa, Itsuro Honda, Naohisa Takagaki and Osamu Kawanami
53 Differences in Flow Around Golf Balls with Different Dimple Occupancy, Volume Ratio and Depth
Kohei Moriyama and Hiroo Okanaga
57 Experiments on flow field control using an acoustic flow generator device
Hideki Kawashima, Shigeyuki Miyazaki and Takamichi Hiroi
76 HEAD-ON VORTEX RING COLLISIONS UPON SMALL LATTICE POSTS
Daniel T. H. New, Chuanhua Liu, Darius Koi Yik Tham, Bowen Xu and Haotian Li
78 EXPERIMENTAL INVESTIGATION ON THE FLOW STRUCTURE OF BUOYANCY VORTICES USING PARTICLE IMAGE
VELOCIMETRY
Ziyang Wang, Neil A. Hawkes, Michael MacDonald, John E. Cater and Richard G.J. Flay
Room G
Technical Sessions G6
GS6: Jet
Session Chair: Masaki Fuchiwaki(Kyushu Institute of Technology)
86 Visualization and measurement of internal flow in a thin vortex chuck research on improvement of silicon wafer adsorption
performance
Fukaya Naoyuki and Funatani Shumpei

JST(UTC+9) Aug.10
10:00-12:00

32 Influence of synthetic jet on multiscale features in wall-bounded turbulence
Biaohui Li and Nan Jiang
55 PRELIMINARY STUDY OF MICROJETS FROM RECTANTULAR CONVEREGNT NOZZLES WITH HIGH-ASPECT RATIOS
Shota Yoshimi, Sinichiro Nakao and Yoshiaki Miyazato
58 PRELIMINARY STUDY OF UNDEREXPANDED SONIC JETS FROM ELLIPTIC CONVERGENT NOZZLES
Tatsuya Nagata, Muhammad M.Islam, Takeshi Miyaguni, Shinitiro Nakao and Yoshiaki Miyazato
75 DETECTION OF LARGE-SCALE STRUCTURES IN A TEMPORAL ROUND JET USING MULTIDIMENSIONAL DYNAMIC MODE
DECOMPOSITION
Mamoru Takahashi, Ren Fukui, Koichi Tsujimoto, Toshitake Ando and Toshihiko Shakouchi
Room HTechnical Sessions H6 ( in Japanese )OS3*(VSJ OS6): Ultrasonic Doppler Methods for Fluid Mechanics and Fluid Engineering
Session Chair: Hiroshige Kikura(Tokyo Institute of Technology)
J63 Fundamental Study on 3D Shape Information Acquisition using Monocular Camera and Ultrasonic Sensor
Kazuya Yasui, Takeshi Moriya, Hideharu Takahashi and Hiroshige Kikura
J68 UVP measurement of near-wall in Taylor-Couette flow with small aspect ratio
Yoshihiko Oishi, Hideki Kawai and Hiroshige Kikura
J85 Bubble sizing in bubbly pipe flow using ultrasound echography
Yuichi Murai, Hyun Jin Park, Yuji Tasaka and Shintaro Akasaka
J90 Visualization of continuously rising bubbles in gallium alloy
Sana Maeda, Hideki Murakawa, Fu Xin and Kazushi Adachi
Room I
Technical Sessions I6
GS2: Multiphase flow (Droplet)
Session Chair: Nao Ninomiya (Utsunomiya University)
8 In-Situ Real-Time Measurement of Droplets Dynamics Using a High-Speed Streaming Camera
Tenshiro Ichimura, Chihiro Inoue and George Kuwabara
10 The Effect of Curvature Distortion on Internal Flow Measurement of a Levitated Droplet using PIV
Eugene Gatete, Kaneko Akiko and Shen Biao
111 VISUALIZATION STUDY ON DROPLET ELECTROHYDRODYNAMIC DEFORMATION IN COMBINED DC ELECTRIC FIELD AND
SHEAR FLOW
Guanqiu Hao, Xiangdong Liu and Yongping Chen
18 Phase-shifting ellipsometer based on pixelated polarization camera to measure nano-thick liquid film and nanoparticle deposits
Eita Shoji, Taiga Saito, Akira Hoshino and Tetsushi Biwa
90 Visualization study of nano particle behavior within pores
Yusaku Abe and Yu Matsuda
99 NANOPARTICLES ACCUMULATION IN A PREDETERMINED POSITION UNDER AC ELECTRIC FIELD
Ahmed Abdelghany, Yuko Okui, Yoshiyasu Ichikawa and Masahiro Motosuke

Day3
Room F
Technical Sessions F7
GS7: Vortex
Session Chair: Yasufumi Horimoto(Hokkaido University )joint session with VSJ

59 OSCILLATORY CHARACTERISTICS OF SHOCK TRAINS IN SQUARE DUCTS
Takato Inadomi, Ryota Fukunaga, Taishi Takeshita, Shinichiro Nakao and Yoshiaki Miyazato
93 STUDY THE EFFECT OF DOWNSTREAM BLUFF BODY TO ENHANCE FIV-BASED ENERGY HARVESTING, A VISUALIZATION
STUDY
Sajjad Hosseini, Aref Afsharfard and Kyung Chun Kim
94 FSI-BASED DESIGN OF A DVA FOR DECREASING UNDESIRED VIBRATIONS OF A ROTATING BEAM, A VISUALIZATIONSTUDYAmirreza Shahsavari, Aref Afsharfard and Kyung Chun Kim
96 STEREO-PIV MEASUREMENT OF A BI-STABLE WAKE BEHIND A SIMPLIFIED SEDAN-TYPE VEHICLE MODEL IN A
CROSSWIND
Chiharu Hasegawa, Takuji Nakashima, Takenori Hiraoka, Taiga Kanehira, Hidemi Mutsuda, Keigo Shimizu and Yusuke Nakamura
5 ACTIVE CONTROL FOR DRAG REDUCTION OF A CIRCULAR CYLINDER BASED ON REINFORCEMENT LEARNING: PIV
MEASUREMENTS OF THE CYLINDER WAKE
Alessandro Scala, Gerardo Paolillo, Carlo Salvatore Greco, Tommaso Astarita and Gennaro Cardone
Room G
Technical Sessions G7
GS4: Numerical visualization and image processing
Session Chair: Takahiro Tsukahara(Tokyo University of Science)
43 CFD ANALYSIS AND VISUALIZATION OF CAVITATING BUBBLY FLOW STRUCTURE IN A CENTRIFUGAL PUMP USING MULTIPROCESS CAVITATION MODEL
Akihisa Yamada, Taiki Takamine, Shin-ichi Tsuda and Satoshi Watanabe
JST(UTC+9) Aug.10
13:00-15:00

67 COMPARISON OF STRAIGHT-SWIMMING PERFORMANCE OF PITCHING WING BETWEEN STEADY AND PERIODIC FLOWS
Yoshitaka Isoda and Yohsuke Tanaka
72 Effect of Surface Wettability for Disk Friction on Rotating Disk in Centrifugal Impeller
Kento Sakai, Yumeno Inaba and Kazuyoshi Miyagawa
85 UNSUPERVISED DEEP LEARNING OF THE STRUCTURAL CHARACTERISTICS IN A TURBULENT CHANNEL FLOW AT A LOWREYNOLDS NUMBER
Mohammad Javad Sayyari, Jinyul Hwang and Kyung Chun Kim
91 Development of Paddlewheel Aerator Performance Predictions Model
Priyambodo Nur Ardi Nugroho, Muh Anis Mustaghfirin, Dwi Sasmita Aji Pambudi, Eky Novianarenti, Dyah Arum Wulandari and Shuichi
Torii
Room HTechnical Sessions H7
OS3*: Ultrasonic Doppler Methods for Fluid Mechanics and Fluid Engineering
Session Chair: Hideharu Takahashi(Tokyo Institute of Technology)
124 ( Session Keynote ) EVOLVING ULTRASONIC VELOCITY PROFILER and eUVP
Yasushi Takeda, Erich Windhab and Hiroshige Kikura
119 FUNDAMENTAL RESEARCH ON COMBINATION OF SOLID-LIQUID LEVEL MEASUREMENT AND ELEMENTALCOMPOSITION ANALYSIS USING ULTRASOUND AND LASER
Yuan Chen, Naruki Shoji, Zeliang Zhang, Tran Tri Vien, Hideharu Takahashi and Hiroshige Kikura
120 Remote Leakage Flow Visualization with Arm-Type Robot and Three-Dimensional Vector UVP
Naruki Shoji, Takeshi Moriya, Yuan Chen, Hideharu Takahashi and Hiroshige Kikura
121 Visualization of Fuel Debris Shape and Measurement of Water Level using Parametric Ultrasound
Tri Vien Tran, Hiroto Tanabe, Hideharu Takahashi and Hiroshige Kikura
122 RANGE EXTENSION ON ULTRASONIC MEASUREMENT OF BUBBLY FLOW VELOCITY PROFILE
Wongsakorn Wongsaroj, Hideharu Takahashi, Natee Thong-Un, Weerachon Treenuson and Hiroshige Kikura
123 Measurement of Multiphase Flow in Rotating Field by Ultrasonic Velocity Profiler
Takumi Konno, Yoshihiko Oishi, Hideki Kawai and Sho Osanai

Floor Map
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Room J, K
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Room Ll VSJ banquet on 18:30-20:00, Aug. 9（Free of charge)
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Kogakuin University AccessPark Hyatt Tokyo Access
ACC E S S MAP

from Shinjuku Station
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10 min.

Park Hyatt Tokyo

Platform 5/6, Narita Express

Free Shuttle Bus Station

5/6 番線 成田エクスプレス

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2F Entrance Map

2階 ホテルエントランスのご案内

The Ballroom
Please come to the 39th floor
from the elevator hall

Bell captain desk

ベルキャプテンデスク

Elevator hall

エレベーターホール

NewomanBusta
Shinjuku
3F

JR Bldg.

MayndsTower

西新宿交差点

3F

Narita Express

AID
HU-K

B1F

甲州街道口

Terrace

Park Hyatt Tokyo

南口

Koshu-Kaido Exit

LABI

KOS

Shinjuku
Washington
HotelSouth Exit

Southern

Doutor Family
Coffee Mart

Shinjuku
Station新宿駅
Lumine2

LumineFirst-Kitchen
The Suit
Company

東口
B1F

中央西口

MylordTokyo
Metropolitan
Govt. Bldg.
No. 2

西口

West Gate

Keio
Dept.
Store

KFC

East Exit

West Exit

2 B1F 1
Central
OdakyuEast Gate
Dept.
中央東口
CentralStore

Main entrance

2F 正面玄関 車寄せ

PSFVIP13-2
GAS HYDRATE FORMATION AND DISSOCIATION UNDER STATIC AND
DYNAMIC CONDITIONS*Y. Nakajima1, J. Yamamoto1, S. Takano1, M. Yamamoto1, M. Ono1, S. Kanada1 and K.
Otsubo11

National Maritime Research Institute, 6-38-1 Shinkawa, Mitaka, Tokyo 181-0004 Japan*nakajima@m.mpat.go.jp
ABSTRACTGas hydrates are ice-like crystalline solids consisting of water and guest molecules such as
methane and carbon dioxide (CO2), and thermodynamically stable under the high-pressure
and low-temperature conditions like permafrost and deep seabed. [1] In Japan, methane
hydrate has been found under the seafloor in the Exclusive Economic Zone so that it isexpected as an unconventional natural gas resource. [2] The authors have investigated thecharacteristics of formation and dissociation of gas hydrates by visual observation. [3] In thisstudy, the formation and dissociation processes of gas hydrates at both static and dynamic
conditions were observed by using a probe-type microscope camera.
In the experiments at static condition, a single pressure chamber was half filled with water,
and pressurized by injection of CO2 gas up to the pressure of ca. 4MPa. While it was cooled
to ca. 2 deg. C, the gas injection into the chamber was continued to keep the inner pressure.
Gas hydrate formation was observed in two stages. In the early stage, although initial gas
hydrate formation was observed on the surface of liquid films on the window, bulk water inthe chamber was expected to be oversaturated by dissolved CO2. As the gas-liquid interface
was continuously disturbed, excess amount of gas dissolved in water was consumed to form
massive gas hydrates in the chamber. As the pressure was lowered, gas hydrates weredissociated to form gas bubbles.
At dynamic condition, two pressure chambers were connected with a straight tube to form atubular vessel. The vessel was settled on a seesaw-type platform so that filling water in thevessel can flow by moving the board of the platform. Two microscope cameras were mounted
on both pressure chambers of the vessel. Gas hydrate formation was initialized in a chamber,then, the vessel was fluctuated on the platform to observe the behaviour of the hydrates,
which was analyzed by image analysis.
REFERENCES[1] Sloan, E.D. and Koh, C.A., Clathrate Hydrates of Natural Gases, 3rd Edition (2007), CRC
Press.
[2] Matsumoto, R., Ryu, B.-J., Lee, S.-R., Lin, S., Wu, S., Sain, K., Pecher, I. and Riedel, M.,“Occurrence and Exploration of Gas Hydrate in the Marginal Seas and Continental
Margin of the Asia and Oceania Region”, Marine and Petroleum Geology, Vol. 28, No.
10 (2011), pp. 1751-1767.
[3] Nakajima, Y., Yamamoto, J., Takano, S., Yamamoto, M., Ono, M., Kanada, S. andOtsubo, K., “Observation of Gas Hydrate Formation at Gas-Liquid Interface”, Proc.
International Conference on Power Engineering-2021 (2021).

PSFVIP13-3

EXPERIMENTAL STUDY ON VORTEX WIDTH AND HYSTERESIS EFFECTOF THE FLOW BETWEEN TWO ROTATING CYLINDERS WITH HIGHASPECT RATIO*Y. Sugimoto1, T. Marumiya1, H. Inatani1, K. Hirata1 and T. Noguchi1
1

Doshisha University, 1-3 TataraMiyakodani, Kyotanabe City, Kyoto, Japan*ctwg0572@mail4.doshisha.ac.jp
ABSTRACTIn this study, we experimentally investigate the influence of the wavenumbers of the
Taylor vortex flow TVF and the wavy vortex flow WVF upon the borders between theregime of the Couette flow CF and the TVF regime and between the TVF regime and the
WVF regime. In order to obtain the steady state mode with an expected wavenumber at
an expected condition, we use a control method based on the hysteresis effect by theacceleration of the inner cylinder rotation.
Flow is visualized by the aluminum powder suspension method. Main dimensions of thepresent experimental setup are 40 mm in the inner cylinder radius, 45 mm in the outercylinder radius, and 945 mm in the cylinder height.
At first, we established the control method of the wavenumber. More specifically, at theouter cylinder Reynolds number Ro = 200 and the inner cylinder Reynolds number Ri =800 in the WVF regime, we can control the normalized wavenumber 2π/λ* in a range of
2.71-3.41. At Ro = 500 and Ri = 700 in the TVF regime, we can control 2π/λ* in a rangeof 3.14-3.53. In the present control, 2π/λ* tends to decrease with increasing rotational
acceleration of the inner cylinder. Next, we show the influence of 2π/λ* upon the borders,
supposing such two initial conditions as (Ro , Ri) = (200, 800) and (500, 700).
As a result, the influence upon the border between the CF regime and TVF regime isnegligible. On the other hand, the influence upon the between the WVF regime and is not
negligible. More specifically, the smaller the wavenumber is, the stronger the influenceof it upon the border is.
REFERENCES[1] G. I. Taylor, Philos. Trans. R. Soc., Ser. A, 223, 289 (1923).
[2] H. Furukawa, T. Watanabe and I. Nakamura - Proc. 9th Int. Symp. Flow Visual, 715 (2000).
[3] C. D. Andereck, S. S. Liu and H. L. Swinney, J. Fluid Mech. Vol.164, 155-183 (1986).

PSFVIP13-4

INVESTIGATION OF THE INFLUENCE OF VASCULAR ACCESS SHAPE ON
HEMODYNAMIC PARAMETERS*H. Anzai1, K. Takeda1,2, A. Kajiyama2, and M. Ohta1
1

Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 9808577 Japan*hitomi.anzai.b5@tohoku.ac.jp
2
Graduate School of Biomedical Engineering, Tohoku University, 6-6 Aramaki-Aza-Aoba,
Aoba-ku, Sendai, Miyagi, 980-8579, Japan

ABSTRACT
Arteriovenous fistulas (AVFs) have been recognized as the gold standard of vascularaccess for hemodialysis. However, the development of postoperative stenosis is a serious
problem. Although it is widely known that hemodynamic stress affects vascular lesions, there
are few reports on hemodynamic changes due to AVF geometry, except for the anastomotic
angle between the artery and vein.
Recently, devices that support blood vessels from the outside have been developed [1].
This has made it possible to maintain a more arbitrary vessel shape after AVF construction. The
purpose of this study is to clarify the effect of vessel shape on hemodynamics when wearing a
support device through parametric study using computational fluid dynamics (CFD).
An AVF model with an ideal shape with straight and curved anastomoses was constructed.
The anastomotic angle α, shunt vessel height HF, x-axis angle β, anastomotic curvature RA, andanastomotic height HA were varied, respectively. Time-averaged wall shear stress (TAWSS),
osciratolly shear index (OSI), and time-averaged vorticity (TAV) were calculated from thetransient analysis using pulsatile waveforms.
The results of CFD analysis for AVF placement show the idealized models with larger α
or large RA had smaller blood flow disturbance. Furthermore, uniform time-averaged WSS
distribution was generated on these models. A uniform WSS distribution is considered topreserve the shape of the vascular lumen and reduce the risk of the vascular lesion such as
stenosis. The operation of vascular shape may improve the hemodynamics which may affectthe onset of vascular lesions such as stenosis.
REFERENCES[1] Chemla, E., Velazquez, C., D’Abate, F., Ramachandran, V., and Maytham, G.,“Arteriovenous fistula construction with the VasQ™ external support device: a pilot study”,
The Journal of Vascular Access, Vol., 17, No., 3(2016), pp. 243-248.

PSFVIP13-5

ACTIVE CONTROL FOR DRAG REDUCTION OF A CIRCULAR CYLINDERBASED ON REINFORCEMENT LEARNING: PIV MEASUREMENTS OF THE
CYLINDER WAKE
*A. Scala, G. Paolillo, C.S. Greco, T. Astarita and G. Cardone*
University of Naples “Federico II”, Via Claudio 21, Naples, 80125, Italy*gennaro.cardone@unina.it
ABSTRACTThe aim of the present work is to investigate, experimentally via Particle Image Velocimetry,the fluid dynamic characteristics of a circular cylinder wake, which is controlled by a synthetic
jet in order to reduce the related aerodynamic drag.
The circular cylinder, placed in an open-circuit wind tunnel, presents a slot in its rear position,
through which the synthetic jet is issued [1]. The latter is obtained by coupling the hollow
interior of the cylinder with a loudspeaker driven by an electrical signal, which is generatedusing a wave generator coupled with a power amplifier. The aerodynamic drag is measured by
two load cells, located at the basis of the cylinder, the output signals of which are amplified andthen acquired through an Arduino card.
Reinforcement Learning [2-3] is applied to find the electrical signal waveshape, supplied to theloudspeaker, that offers the largest reduction of the cylinder aerodynamic drag. In particular,
two different shapes are tested: those obtained as Fourier series at a chosen fundamental
frequency and those obtained by varying the duty cycle of a sinusoidal signal. The latter arefound to reduce more the cylinder aerodynamic drag.
Starting from the identified optimal waveshape, the use of Particle Image Velocimetry allows
to obtain the instantaneous two-dimensional velocity fields in a plane containing the synthetic
jet slot; these measurements are used to investigate the mean flow quantities and turbulent
statistics of the phenomenon.
REFERENCES[1] Greco, C.S., Paolillo, G., Astarita, T., and Cardone, G., “The von Kármán street behind acircular cylinder: Flow control through synthetic jet placed at the rear stagnation point”,
Journal of Fluid Mechanics, 901 (2020).
[2] Fan, D., Yang, L., Wang, Z., Triantafyllou, M.S., and Karniadakis, G.E., “Reinforcement
learning for bluff body active flow control in experiments and simulations”, Proceedingsof the National Academy of Sciences, 117(42), 26091-26098, (2020).
[3] Brunton, S.L., Noack, B.R., Koumoutsakos, P., “Machine learning for fluid mechanics”,
Annual Review of Fluid Mechanics, 52, 477-508, (2020).

PSFVIP13-6
START-UP CHARACTERISTICS OF LOOP HEAT PIPE WITH PLATE-TYPE
EVAPORATOR*Tomohiro Nakazawa1, Atsushi. Tsujimori2, Tsubasa Usui1, Koji Ono1,
Reo Miwa1, Norifumi Miyanaga2, Yui SATO2 and Haruka Suzuki2
1

Graduate School, Kanto Gakuin University, 1-50-1 Mutsuurahigashi, Kanazawa, Yokohama,
Kanagawa 236-8501, Japantujimori@kanto-gakuin.ac.jp
2
Kanto Gakuin University, 1-50-1 Mutsuurahigashi, Kanazawa, Yokohama, Kanagawa 2368501, Japan
ABSTRACTIn this study, experimental equipment with a plate-type evaporator was manufactured and its
start-up characteristics were investigated. The evaporator consisted of an upper part, a porous
carbon wick, and a lower part. The upper part was used as the reservoir for the liquid refrigerant.
In the lower part, grooves for the vapor paths were machined and were lined with porous carbon
with a pore diameter of 5 µm. To visualize the flow of the working fluid in the vapor paths ofthe evaporator during start-up, the lower part of the evaporator with grooves was made of apolycarbonate resin plate. In the experiment, a heat load was applied to the evaporator from thebottom side and the refrigerant in the vapor paths was observed. The experimental results showthat it took several minutes for the liquid refrigerant in the vapor paths to start evaporating andabout 30 s for the vapor paths to be filled with refrigerant vapor. Moreover, the vaporization
started from the fluid-merging part and then expanded to the branches of the vapor paths. We
also constructed a calculation model for only the vapor paths, and the calculation results showthat the two-phase flow flows out to the vapor line as in the experimental results, but thevaporization starts from the edge of the branches of the vapor paths. It is considered that in theexperiment, the capillary wick was set on the vapor paths in the evaporator and the liquid
refrigerant in the vapor paths was pushed by the generated refrigerant vapor and flowed out not
only to the vapor line but also to the reservoir through the capillary wick, which caused thedifference between the calculation and experimental results.
REFERENCE[1] K. Takenouchi, A. Tsujimori, M. Maruoka and K. Togashi, “Start-up Characteristics ofLoop Heat Pipe”, 5th International Conference on Design Engineering and Science, (2020),
pp. 117–122.

PSFVIP13-7

VISUALIZATION OF INTERMITTENT TURBULENT STRUCTURE
IN ECCENTRIC ANNULAR PIPE FLOW
*K. Yatsushiro 1, Y. Horimoto2 and T. Tsukahara1
1

Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 Japan*7521555@ed.tus.ac.jp
2
Hokkaido University, N13 W8, Sapporo, Hokkaido 060-8628 Japan

ABSTRACT
Annular pipe flow is common in industrial applications and has attracted researchers’ interest
because of the variety of its intermittent turbulent states, i.e., localized turbulence, for theconcentric annular flow [1]. The eccentric annular pipe flow and its heat and mass transfers arealso practically important, since the actual equipment is more or less eccentric. A recent study[2] revealed that the critical Reynolds number of a linear instability and the quasi-periodic
coherent structures were significantly dependent on the eccentricity. The purpose of this study
is to experimentally investigate the dependences of the eccentricity and the radius ratio on thelocalized turbulence and coherent structures in a transitional Reynolds-number regime.
We used an apparatus consisting of one fixed outer pipe and radially-movable inner pipe, whose
diameters are respectively Do = 14 mm and Di = 2–6 mm corresponding to the radius ratio of γ
≡ Di/Do = 0.14–0.43. The eccentricity is defined as ε = 2d/Dh, where d is the distance between
the pipe axes and Dh (= Do − Di) is the hydraulic equivalent diameter. We examined four ε of
0 (concentric) and 0.2–0.8 (eccentric). The pipe length is 2600 mm (> 210Dh). For visualization
with light-reflective mica flakes, we used two mirrors that allow us to observe the entire flow
simultaneously from 3 azimuthal directions to grasp the stereoscopic structures. We determined
the transition processes of flow states from developed turbulence to laminar, with detecting
localized turbulent regions.
In the concentric annular pipe flow, we confirmed the presence of helical pattern of localized
turbulence, as Ishida et al. [1] demonstrated only in their numerical simulations. The helicalshape was successfully demonstrated by our multi-directional observation. Our experiments
revealed that the increase in the radius ratio decreased the Reynolds number of relaminarization.
Interestingly, intermittent turbulent structures appeared at very low Reynolds numbers for theeccentric cases, regardless of the radius ratio. The localized turbulence for ε = 0.2–0.4 survived
at much lower Reynolds numbers that the critical value for ε = 0.
REFERENCES[1] Ishida, T., Yohann, D. and Tsukahara, T., “Transitional structures in annular Poiseuilleflow depending on radius ratio”, Journal of Fluid Mechanics, Vol. 794 (2016), R2.
[2] Lamarche-Gagnon, M.-É and Tavoularis, S., “Further experiments and analysis on flow
instability in eccentric annular channels”, Journal of Fluid Mechanics, Vol. 915 (2021),
A34.

PSFVIP13-8

IN-SITU REAL-TIME MEASUREMENT OF DROPLETS DYNAMICSUSING A HIGH-SPEED STREAMING CAMERA*T. Ichimura1, C. Inoue1, G. Kuwabara2
1

Kyushu University, 744 Motoka, Nishi-ku, Fukuoka 819-0385 Japan*ichimura.tenshiro.489@s.kyushu-u.ac.jp
2
Photron Ltd., Kandajimbocho, Chiyoda-ku, Tokyo 101-0051 Japan

ABSTRACTHigh speed imaging is a beneficial approach to clarify time-resolved multi-phase flow, such as
droplet dynamics in a spray. However, it has been necessary to separate the image capturing
step and the analysis step for quantitative measurement; thus, it has been recognized that thehigh-speed imaging is distinct from a real-time measurement technique. Real-time high-speed
measurement for a spray is suitable for inspection of products and for feedback control of flow
system. Recently, a high-speed streaming camera is developed, which can take images over
1kHz and translate them to a PC in a simultaneous manner, potentially allowing for the highspeed real-time measurement of multi-phase flow.
We employ a high-speed streaming camera (Photron INFINICAM UC-1), controlled by inhouse C++ program implementing the image processing library of OpenCV, achieving the nontracking measurement of drop size distribution and the Particle Tracking Velocimetry (PTV)
for drop size and velocity. A laptop PC (MSI Delta15) is used for the in-situ measurement.
We successfully quantify diameters for the number of 10,000 droplets and deduce the size
distribution within approximately 1 second, achieving a processing speed of 2.5 kHz at theimaging framerate of 1kHz. Then, we measure diameter and velocity of a single free-falling
droplet. Time-step for the PTV analysis considers the sequence number tagged to each image
to avoid calculation of missing images. The processing speed is greatly improved by using thevelocity information of the droplet to restrict the search are. The PTV is successfully conducted
in real-time at a processing speed of over 1kHz. The measurement accuracy is calculated bycomparing the measured droplet velocity with the theoretical free-fall velocity, convincing thatthe measurement accuracy is more than 90% for a droplet without deformation.
REFERENCES[1] Fischer, A., “Fundamental flow measurement capabilities of optical Doppler and time-offlight principles”, Experiments in Fluids, Vol. 62, No. 2 (2021).
[2] Shaffer F., Ibarra E., and Savaş Ö., “Visualization of submerged turbulent jets using
particle tracking velocimetry”, Journal of Visualization, Vol. 24, No.4 (2021), pp.699-710.

PSFVIP13-9

COMPARISON OF HEMODYNAMICS IN LEFT VENTRICLES WITH TRICUSPIDAORTIC VALVE AND BICUSPID AORTIC VALVES*Shingo Tsuda1,2, Suguru Miyauchi3, Kenichi Funamoto1,2,4
1

Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-aza Aoba, Aoba-ku,
Sendai, Miyagi 980-8579, Japan*tsuda.shingo.t1@dc.tohoku.ac.jp
2
Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 9808577, Japan
3
Faculty of Engineering, University of Miyazaki, 1-1 Gakuen Kibanadai-nishi, Miyazaki,
Miyazaki 889-2192, Japan
4
Graduate School of Biomedical Engineering, Tohoku University, 6-6-12 Aramaki-aza Aoba,
Aoba-ku, Sendai, Miyagi 980-8579, Japan
ABSTRACTThe aortic valve between the left ventricle (LV) and the aorta is generally a tricuspid valve (TV)with three cusps, but it is a congenital bicuspid valve (BV) with only two cusps for 0.5%-1.0%
in the whole population. The BV reportedly increases a risk of aortic diseases, such as aortic
dissection and aneurysm, by causing a jet flow of blood [1, 2]. However, the detailed changes
by aortic valve morphology on hemodynamics remain to be understood. The purpose of thisstudy was to clarify the effect of BV on hemodynamics in the LV located at the upstream of theaorta. We constructed a LV model from magnetic resonance imaging of the LV in a healthy
volunteer, adding simplified internal structures of trabeculae carneae and papillary muscles andassuming a deformation during a pulsation [3]. A TV or two types of BV with different opening
shapes and areas were installed at the aortic valve position [2, 4]. Numerical simulation of bloodflow was then performed with the three LV models to compare the velocity field, vortex
structure, and hemodynamic parameters such as wall shear stress (WSS). LV models with BVs
showed a larger velocity of blood flow that formed a jet flow from the LV to the aorta and alarger time-averaged WSS near the aortic valve than that with TV. These findings support thatthe BV might contribute to the above-mentioned aortic diseases. As for vortex structures in the
LV, no clear difference was observed between the models. But, between the BV models, there
was a difference in the flow velocity, resulting from the valve positions even if their opening
areas were equivalent. Thus, the aortic valve morphology changes blood flow ejected from the
LV, and it is important to employ a model integrated the LV and the aorta for hemodynamic
analysis in the aorta.
REFERENCES[1] Levack, M.M., et al., “Quantitative three-dimensional echocardiographic analysis of thebicuspid aortic valve and aortic root: A single modality approach”, Journal of Cardiac
Surgery, Vol. 35, No. 2 (2020), pp. 375-382.
[2] Chandran, K.B., et al., “Patient-specific bicuspid valve dyna-mics: Overview of methods
and challenges”, Journal of Biomechanics, Vol. 46, No. 2 (2013), pp. 208-216.
[3] Hosoi, K., et al., “Numerical Analysis of the Effect of the Inner Structure of a Left
Ventricle on the Blood Flow Field: Effect of Papillary Muscles and Trabeculae Carneaes”,
Proceedings of the 15th International Conference on Flow Dynamics (ICFD2018), (2018),
pp. 622-623[4] Haimerl, J., et al., “Quantification of aortic valve area and left ventricular muscle mass inhealthy subjects and patients with symptomatic aortic valve stenosis by MRI”, Zeitschrift
fur Kardiologie, Vol. 94, No. 3 (2005), pp. 173-181.

PSFVIP13-10

THE EFFECT OF CURVATURE DISTORTION ON INTERNAL FLOW
MEASUREMENT OF A LEVITATED DROPLET USING PIV*1*Eugene GATETE 1，Akiko KANEKO2 and Shen Biao3
Department of Engineering Mechanics and Energy, University of Tsukuba* egateos48@gmail.com and s2130194@u.tsukuba.ac.jp

2

Department of Engineering Mechanics and Energy, University of Tsukuba, 1-1-1Tennodai,
Tsukuba, Ibaraki, Japan3
Department of Engineering Mechanics and Energy, University of Tsukuba, 1-1-1Tennodai,
Tsukuba, Ibaraki, Japan
ABSTRACTVisualization of the curvature distorted internal flow in levitated droplets is crucially needed
due to the application of droplet dynamics in different areas of engineering, medical sciences,material engineering, and so on. In the present study, an acoustically levitated droplet isfocused on and particle image velocimetry (PIV) is used to visualize and measure flow fields
inside the droplet as the measurement technique. Although the flow structure in the levitateddroplet is required in order to understand the internal flow structure of the droplet, it is limitedby the low Web number and curvature distortion when visualization approaches are applied.
Researchers have studied droplet levitation technologies, however, there is still lessexperimental and analytical information about the effect of curvature distortion on theinternal flow of a levitated droplet. To understand the flow field inside an acousticallylevitated droplet with high accuracy, it is important to experimentally investigate the effectof the parameters that influence the curvature distortion development of the flow inside thedroplet. The aim of this research is to visualize and investigate the effect of curvature
distortion on the internal flow measurement of a levitated droplet which will lead to thecurvature distortion correction. In this study, the effect of curvature distortion on internal
flow elucidation was performed based on the refractive index, surface tension, sound pressure,and diameter. The internal flow fields were experimentally investigated and visualized using
the PIV. The experimental results showed that the internal flow curvature distorted increases
as the refractive index, sound pressure, and surface tension increase.

Keywords: Acoustic levitation, Aspect ratio, Curvature distortion, internal flow, Particle image
velocimetry (PIV), and Refractive index.

PSFVIP13-11
COMPUTATIONAL MODELING OF THE SPONGE’S CHOANOCYTE CHAMBER*Takumi Ogawa1, Toshihiro Omori1, Kenji Kikuchi1, and Takuji Ishikawa1
1

Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 Japan*takumi.ogawa.t2@dc.tohoku.ac.jp

ABSTRACT
Sponges are the evolutionarily oldest animals among multicellular organisms. They are filter
feeders enclosing the choanocyte chamber with tens of flagella, and they can filter a volume ofwater several times their body volume[1]. The choanocyte chamber consists of uni-flagellated
collar cells arranged in a spherical configuration, and the wave of flagellar beating propagates
toward the center of sphere. The wave of flagella creates a flow of water within the choanocyte
chamber, and nutrients in the water are filtered by the collar around the flagellum for feeding[2].
Though flagellar driven flow in choanocyte chamber is important for the filter feeding, the flow
field within the choanocyte chamber has not been clarified. How can a spherically symmetricalflagellar arrangement produce a unidirectional flow? To break the symmetry, inner structures
within the choanocyte chamber, such as membrane and cone cell ring[3], are thought to play arole.
In this study, we developed a three-dimensional choanocyte chamber model using a boundary
element-slender-body coupling method to clarify the mechanism of the pumping function
induced by the flagellar beat. We investigated the flagellar driven flow rate through the outletof the chamber and the effect of inner structures on the outlet flow rate.
We found that the inner structures contribute to create unidirectional flow by preventing water
circulation around the outlet. As a result, the outlet flow rate was enhanced by combination of
the membrane and cone cell ring, and it reaches more than two times larger than that of nointernal structure model.
REFERENCES[1] Asadzadef, S.S. et al. “Hydrodynamics of the leucon sponge pump”, Journal of The Royal
Society Interface, Vol. 16, (2019).
[2] Ludeman, D.A. et al. “The energetic cost of filtration by demosponges and their
behavioural response to ambient currents”, Journal of Experimental Biology, Vol. 220,(2017), pp. 4743-4744.
[3] Langenbruch P. et al. “Canal systems and choanocyte chambers in freshwater sponges(Polifera, Spongillidae)”, Zoomophology, Vol. 107, (1987) pp. 11-16.

PSFVIP13-12

MULTISCALE FLOW STRUCTURES IN A CUBE WAKE INFLUENCED BY THE
FRONT INCLINED HOLE
*Jiawei Li1, Xiaolei Han1, Hiroka Rinoshika2 and Akira Rinoshika1,2
1Ministry of Education Key Laboratory of Fluid Mechanics, Beijing University of
Aeronautics and Astronautics, Beijing 100191, China*lijiawei@buaa.edu.cn
2
Department of Mechanical Systems Engineering, Yamagata University, 4-3-16 Jonan,
Yonezawa-shi, Yamagata 992-8510, Japan

ABSTRACTTime-resolved particle image velocimetry (TR-PIV) is used to experimentally study the multiscale wake structures of a wall-mounted cube and the effects of a front inclined hole (FIH). The
cube model has a side length of D = 50 mm, and the Reynolds number ReD is 7800. The inletof FIH is located at the height of 0.71D on the front surface of the cube, and the outlet is locatedat the center of the free end. The statistical analysis, the orthogonal wavelet multi-resolution
analysis, and the vortex dynamics are applied to this study. The statistical results show that FIH
can reduce the recirculation zone around the cube, inhibit the downwash flow, and change thedevelopment of free-end shear flow. The turbulence intensity and turbulent kinetic energy (TKE)in the wake also decreased significantly due to FIH. Multi-scales flow structures in cube wake
are extracted by the wavelet multi-resolution analysis. From the shear layer around the cube to
the near wake and then to the far wake, the main structures of the flow field experience thetransformation process of small- to middle- and then to large-scale structures. Under the
influence of FIH, the scale of the flow structure near the free end is smaller, the large-scale
structure in the wake is weakened, and the transition from small- to middle-scales is no longer
obvious. The vortex dynamics analysis reveals the existence and evolution of vortex structureswith different scales. Because of FIH, the trend moving to the bottom wall of large- and middlescale coherent structures is weakened, while the existent range in streamwise of small-scale
structures has longer. In the large-scale component of wake, we found the transverse secondary
vortex, which is formed by the combined action of the shedding transverse vortex and the
downwash flow.
REFERENCES[1] Li, J., Rinoshika, H. and Rinoshika, A., “Effect of front inclined hole on flow structurearound a wall-mounted cube”, Experimental Thermal and Fluid Science, Vol. 120 (2021).
[2] Rinoshika, A. and Zhou, Y., “Orthogonal wavelet multi-resolution analysis of a turbulent
cylinder wake”, Journal of Fluid Mechanics, Vol. 524 (2005), pp. 229-248.
[3] Li, J., Rinoshika, H. and Rinoshika, A., “Passive control on wake structure of a wallmounted cube by using a horizontal hole”, Ocean Engineering, Vol. 213 (2020).
[4] Shadden, S.C., J.O. Dabiri and J.E. Marsden, “Lagrangian analysis of fluid transport inempirical vortex ring flows”, Physics of Fluids, Vol. 18, No. 4 (2006).

PSFVIP13-13

FUNDAMENTAL STUDY OF MR-MEASUREMENT-INTEGRATED SIMULATIONOF HEART-AORTA-SYSTEM: APPLICATION TO AN AORTIC ARCH
*Suguru Miyauchi1, Madoka Kon2,3, Toshiyuki Hayase4
1

Faculty of Engineering, University of Miyazaki, 1-1, Gakuen Kibanadai-nishi, Miyazaki,
Miyazaki 889-2192 Japan*suguru.miyauchi@cc.miyazaki-u.ac.jp
2
Insitute of Fluid Science, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 9808577 Japan3
School of Engieering, Tohoku University, 6-6, Aramaki-aza Aoba, Aoba-ku, Sendai, Miyagi
980-8579 Japan
4
Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3, Aramakiaza Aoba, Aoba-ku, Sendai, Miyagi 980-8578 Japan

ABSTRACT
Since the initiation and progression of cardiovascular diseases are related to hemodynamics, it
is important to obtain accurate hemodynamic parameters. Clinical measurements including
magnetic resonance (MR) imaging and computational fluid dynamics (CFD) simulation are
mainly used to investigate the parameters. MR imaging can obtain information on vasculargeometry and blood flow non-invasively, but the accuracy of MR data is relatively low. On theother hand, CFD simulation can obtain detailed information on the blood flow field, but it isdifficult to give accurate boundary conditions. To compensate the above-mentioned drawbacksof the MR imaging and CFD simulation, MR-measurement-integrated (MR-MI) simulation has
been developed [1]. In the MR-MI simulation, MR data are fed back to numerical simulations
to reproduce actual blood flow fields. The effectiveness of the MR-MI simulation wasdemonstrated for blood flows in descending and ascending aortas [2, 3], which are known as
the common sites of the aneurysm. The purpose of this study was to obtain accurate blood flow
field in an aortic arch using the MR-MI simulation. In this study, three kinds of simulations
were compared: the ordinary CFD simulation in which the flow rate obtained by MRI was given
to the inlet boundary condition, the ordinary CFD simulation in which the inlet flow rate wascorrected to minimize the difference between the measured and computed mean flow velocities
in the direction of the blood vessel axis in the region of interest (ROI) set at the arch, and the
MR-MI simulation. As the result, the flow velocity error in the ROI was reduced by thecorrection of the input flow rate and the feedback of the MR data. In addition, the more
complicated temporal-spatial variation in the wall shear stress was reproduced by the MR-MI
simulation compared to those of ordinary simulations. These results show the effectiveness of
the MR-MI simulation to the blood flow in the aorta.
REFERENCES[1] Funamoto, K., et al., Annals of Biomedical Engineering, Vol. 37, No. 6 (2009), pp. 11051116.
[2] Ogitsu, M., et al., 14th International Conference on Flow Dynamics, (2017), pp. 264-265.
[3] Hori, Y., et al., 16th International Conference on Flow Dynamics, (2019), pp. 444-445.

PSFVIP13-14

TIME-RESOLVED VISUALIZATION OF HEAT FLUXES FROM NEAR-WALL
TURBULENT FLOWS.

I. Znamenskaya, E. Koroteeva, V. Chirich, M.Muratov
znamen@phys.msu.ru
Lomonosov Moscow State University, 119991, Leninskie Gory, 1, Moscow, Russia

Infrared thermography with high spatio-temporal resolution offers promising new approachfor truly noninvasive measurement of turbulent characteristics in the near-wall flow region.
If the material of walls bounding the flow is infrared opaque (metal walls of a shock tube
channel), the recorded heat fluxes are emitted from the outer wall surfaces and the inverse
heat transfer problem needs to solved to obtain the turbulent temperature fluctuations within
the fluid [1]. Heat fluxes from the outer shock tube wall surfaces 1,5-2 mm thick were tested.
An infrared-transparent bounding wall, allows direct real-time measurements of heat fluxes
from the fluid flow. If the studied fluid is liquid water, the recorded fluxes are emitted from anear-wall water layer, a fraction of a millimeter thick [2]. The approach is based on following
the dynamics of the thermal spots - temperature inhomogeneities induced by turbulent mixing- that serve as passive flow tracers. In this work, thermal imaging of near-wall temperaturefluctuations at frames rates up to 900 Hz is performed to gain new insights into the turbulent
properties of impinging jet flows of various configurations. We considered a submerged water
jet exiting a pipe with a circular nozzle, D = 2 mm or D = 3 mm in diameter. The pipe wasplaced in a large square glass reservoir tank filled with room temperature water. The nozzle
was located at a distance H (from 2D to 4D) from the infrared-transparent window made of a
2-mm thick CaF2 slab, 50 mm in diameter. The window also served as an impingement plate.
The jet exit Reynolds numbers, Re, based on jet exit velocities were between 5000 and 25000.
The contrast on thermal images was achieved by keeping the jet temperature 5-10 °C above
the ambient water temperature. Turbulent mixing of warm and cold water within submillimeter boundary layer induced thermal fluctuations that could be associated with flow dynamics.
The distributions of calculated root mean square values of fluctuating near-wall apparent temperature were obtained. The analysis of thermal images allows detecting the regions of highest turbulent fluctuations and flow transition zones. Thus, the proposed measurement technique provides new insights into the turbulent properties of the near-wall flow generated by
the interaction of an impinging jet with a ribbed surface and facilitates the prediction of heattransfer to the impingement wall. The results demonstrate how the presence of the rib on asmooth wall changes the distribution of turbulent fluctuations depending on flow geometry the locations of near-wall regions with minimal flow perturbation (around the flow stagnation
point) and regions with intensive turbulent mixing.

REFERENCES
1. Tiselj I., Horvat A., Mavko B., Pogrebnyak et al. Wall properties and heat transfer in nearwall turbulent flow. Numerical Heat Transfer, Part A: Applications, 46(7), 717–729, 2004
2. A. M. Shagiyanova, E. Yu Koroteeva, I. A. Znamenskaya, et al. Analysis of the visualization region in near-wall fluid layer by high-speed infrared thermography. Moscow University Physics Bulletin, 75(2), pp. 143–147, 2020.

PSFVIP13-16
SIMULATION OF A PACKED SUSPENSION OF MICROSWIMMERS*Y. Kogure1, T. Omori1, and T. Ishikawa1
1

Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 Japan*yu.kogure.s1@dc.tohoku.ac.jp

ABSTRACT
There are various packed suspensions of microswimmers in nature. Among them, red tidecaused by microscopic algae and biofilms generated by bacteria have a relationship to problems
such as damage to fisheries and contaminations of medical equipment. Mass transport in
microorganism suspension is one of the most important factors involved in cell growth and theirhabitat, so understanding the transport phenomena leads to our prediction and control of their
expansion, and solution of the above-mentioned problems. Previous studies have mainly
analyzed mass transport in dilute and semi-dilute suspensions of microorganisms, but rarely
featured mass transport in a concentrated suspension. This study aims to develop the model ofquantifying transport phenomena in a dense suspension of swimming microorganisms and toevaluate the flow field, mass transport of substances, and nutrient uptake.
Each swimming microorganism was modeled by the squirmer which swims generating slip
velocities on its body surface. The squirmer changes motility by swimming modes and thenrepresents various swimming of microorganisms. Squirmers were assumed to be arranged in
the body-centered cubic lattice with a volume fraction of 50%, structurally stuck, and oriented
in the same direction due to taxis. The flow around squirmers can be approximated as Stokes
flow, so the velocity field around them was calculated by the boundary element method withthe triply periodic boundary condition. To evaluate mass transport in a suspension, we
calculated motions of particles with Brownian diffusion by Lagrange description. Then, we
introduced the Peclet number, which indicates whether the mass transport is advection or
diffusion dominated, as a parameter. The net flow in a suspension was set to be zero, with
applying the triply periodic boundary condition.
We have successfully developed a numerical code for simulating transport phenomena in apacked suspension of squirmers. The flow structures and velocity fields generated by squirmers
differed with swimming modes, so the motions of particles differed with the velocity fields.
They were also dependent on the Peclet number. Thus, mass transport depended on the velocity
fields with various swimming modes and the Peclet number.
REFERENCES[1] Ishikawa, T., Locsei, J. T., and Pedley, T. J., “Fluid Particle Diffusion in a SemidiluteSuspension of Model Micro-organisms”, Physical Review E, Vol. 82, (2010), 021408.
[2] Blake, J. R., “A Spherical Envelope Approach to Ciliary Propulsion”, Journal of Fluid
Mechanics, Vol. 46, (1971), pp. 199-208.

PSFVIP13-17

MASS TRANSFER AND VELOCITY MEASUREMENTS IN T-JUNCTION PIPINGSYSTEM
Kazuki Munemura1, Kazuki Kawaguchi1, *Takayuki Yamagata1, and Ryo Morita2
1

Niigata University, 8050 Ikarashi 2-Nocho, Nishi-ku, Niigata, Niigata 950-2181 Japan*yamagata@eng.niigata-u.ac.jp
2
Central research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka-shi,
Kanagawa 240-0196 Japan

ABSTRACT
Prediction and management of pipe-wall thinning in fossil and nuclear power plants areimportant for safety management and stable supply of electricity. One of the main causes of thepipe-wall thinning is flow accelerated corrosion [1], which is a mass transfer phenomenon fromthe pipe-wall surface into the fluid. T-junction pipe used for branching or merging pipes in thepiping system is a representative element in which the pipe-wall thinning occurs frequently.
Thermal striping phenomenon caused by the merging of fluids with temperature differences
have mainly investigated in the T-junction pipe [2]. This study revealed that the flow pattern
after merging changed depending on the flow velocity ratio of the main pipe and branch pipe.
The mass transfer in the T-junction pipe is recently investigated by numerical simulation [3].
Therefore, there are few reports on the experimental investigations of the mass transfer in the
T-junction. The purpose of this study was to investigate experimentary the influence of the flowrate ratio of the main pipe and branch pipe on the mass transfer and velocity field in T-junction
pipe. The experimental evaluation of the mass transfer and veloicty field was carried out in aclosed-curcuit water tunnel. The mass transfer coefficient was measured by the plasterdissoluition method and the velocity field was measured by particle image velocimetry withdifferent flow rate ratio of the main pipe and branch pipe [4]. The mass transfer coefficient of
the experiment showed two peaks after the main pipe and the branch pipe merged. The
maximum value increased as the flow rate from the branch pipe increased. Flow separation wasenhanced near the wall surface on the branch pipe side at that condition.
REFERENCES[1] Sanchez-Caldera, L.E., Griffith, P., Rabinowicz, E., “The mechanism of corrosion-erosion
in steam extraction lines of power stations”, ASME Journal of Engineering for Gas
Turbines and Power, Vol. 110 (1988), pp. 180-184.
[2] Kamide, H., Igarashi, M., Kawashima, S., Kimura, N., Hayashi, K., “Study on mixing
behaviour in a tee piping and numerical analyses for evaluation of thermal striping”,
Nuclear Engineering and Design, Vol. 239 (2009), pp. 1192-1200.
[3] Watanabe, S., Morita, R., “Characteristic of pipe wall thinning by flow accelerated
corrosion at drift region in junction piping”, Transactions of the JSME, Vol. 86 (2020), 2000110 (16 pages).
[4] Taguchi, S., Ikarashi, Y., Yamagata, T., Fujisawa, N., Inada, F., “Mass and momentum
transfer characteristics in 90° elbow under high Reynolds number”, International
Communications in Heat and Mass Transfer, Vol. 90 (2018), pp. 103-110.

PSFVIP13-18

PHASE-SHIFTING ELLIPSOMETER BASED ON PIXELATED POLARIZATIONCAMERA TO MEASURE NANO-THICK LIQUID FILM AND NANOPARTICLEDEPOSITS*E. Shoji1, T. Saito1, A. Hoshino1 and T. Biwa1
1

Tohoku University, 6-6-01 Mechanical Systems Engineering, 980-8579 Japan*eita.shoji@tohoku.ac.jp

ABSTRACT
Environmental-friendly processes utilizing inkjet technology, e.g., printed electronics, arebeing developed. The wetting phenomena in the processes have been widely studied because
the products, i.e., the structure of the deposits that remain on the substrate, are closely related
to the wetting behavior of the inkjet droplets. Especially in recent years, nanofluids containing
nanoparticles have attracted attention as nano-ink, and since nanoparticles can exist in nanothick liquid films that develop near the contact line under certain conditions, methods formeasuring the liquid films and nanoparticle deposits will become increasingly important.
Therefore, this study aims to develop a phase-shifting ellipsometer based on a pixelated
polarization camera and measure the shape of the liquid films and nanoparticle deposits.
The principle of the developed ellipsometer is based on an existing phase-shifting
ellipsometer developed by the authors[1]. The difference between them is the algorithm in thephase-shifting technique and the way to introduce the phase shift. The previous system required
synchronization of the azimuthal angle of the rotating polarizer and camera, but thissynchronization is no longer necessary with the use of the polarization camera in the present
system. This provides better temporal resolution than previous studies[2].
In the experiments, alkanes, such as n-octane and n-decane, were used as solvents anddecanoic acid-modified CeO2 nanoparticles[3] with a diameter of approximately 6 nm wereadded to the alkanes. A droplet of the nanofluids was ink-jetted on a Si substrate. The amountof droplets on the substrate was controlled by the number of ink-jetted droplets with a volume
of approximately 250 pL per droplet. In the experiment using n-octane solvent, a ring-shaped
particle layer was formed at conditions with a maximum contact radius of more than 100 μm,
and the inside of the ring was uniform thickness with 1–2 nanoparticles. As the droplet volume
increased, the development of the nano-thick liquid film emanating from the contact line wasobserved, and nanoparticles deposition within the film was also observed.
REFERENCES[1] Shoji, E., Komiya, A., Okajima, J., Kubo, M. and Tsukada, T., “Three-step phase-shifting
imaging ellipsometry to measure nanofilm thickness profiles”, Optics and Lasers inEngineering, Vol. 112, (2019), pp. 145–150.
[2] Shoji, E., Kaneko, T., Yonemura, T., Kubo, M., Tsukada, T. and Komiya, A.,“Measurement of dynamic wetting using phase-shifting imaging ellipsometer: comparisonof pure solvent and nanoparticle suspension on film thickness profile, apparent contact
angle, and precursor film length”, Experiments in Fluids, Vol. 62, (2021), pp. 1–13.
[3] Zhang, J., Ohara, S., Umetsu, M., Naka, T., Hatakeyama, Y. and Adschiri, T., “Colloidal
Ceria Nanocrystals: A Tailor-Made Crystal Morphology in Supercritical Water”,
Advanced Materials, Vol. 19, (2007), pp. 203–206.

PSFVIP13-19
VISUALIZATION OF FLOW FIELD INDUCED BY HYDRODYNAMIC
INTERACTIONS OF SWIMMING MICROORGANISM*K. Kubo1, T. Omori1 and T. Ishikawa1
1

Tohoku University,6-6-01 Aoba Aramaki Aoba-ku , Sendai, Miyagi 980-8579 Japan*kiyoto.kubo.q5@dc.tohoku.ac.jp

ABSTRACT
Aquatic swimming microorganisms are ubiquitous in nature and have a major impact on the
global environment. For example, accumulation of planktonic microorganism in ocean can be
related to toxic red tides that are detrimental to fishing industries. It has been reported that theinteraction between the motility of microorganisms and the background flow caused by ocean
currents and winds is important in the aggregation process of plankton [1], and it is necessary
to elucidate the fluid motion around microorganisms to describe their population dynamics. In
particular, there is a need to understand the nearby fluid motions that govern microbial
aggregation and interactions, as well as cell-scale flows within microbial suspensions. In thisstudy, we developed a computational model of dense suspensions of swimming
microorganisms and quantified cell-cell interactions by visualizing the flow field in thesuspension. Especially, we will discuss the effects of the cell deformability on thehydrodynamic interactions.
The microorganism is assumed to be a ciliate and is modeled as a capsule of a hyperelastic
thin membrane enclosing a Newtonian fluid in order to take the membrane deformability into
account [2]. The area incompressibility and shear resistance of membrane are described by the
Skalak constitutive law [3]. The model has torque distribution slightly above the membrane fora propulsion [2]. A solid mechanics of the cell membrane is solved by a finite element method.
Due to small Reynolds number of microorganism motion, the fluid flow is assumed to be
governed by the Stokes equation, which is solved by the boundary element method. This model
solves a fluid-structure interaction, which couples the two-way interaction between the fluid
and the cell membrane. The motion of microorganisms is computed under triply periodic
boundary. Ewald summation and multipole expansion techniques are used to decrease thecalculation costs.
We have successfully simulated flow fields in very dense microbial suspensions with avolume fraction of 20% and visualized the flow field formed by interacting microorganisms.
Different swimming modes are expressed by varying the torque distribution. Cell-cellinteractions produced by the different swimming modes are discussed.
REFERENCES[1] Durham, W.M., Kessler, J. and Stocker, R., “Disruption of vertical motility by shear
triggers formation of thin phytoplankton layer”, Science, Vol. 323 (2009), pp. 1067-1070.
[2] Matsui, H., Omori, T., and Ishikawa, T., “Hydrodynamic interaction of two deformabletorque swimmers”, J. Fluid Mech. 894, A9 (2020).
[3] Skalak, R., Tozeren, A., Zarda, R. P. and Chien, S., “Strain energy function of red blood
cell membranes”, Biophys. J., 13 (1973), pp. 245-264.

PSFVIP13-20
MODELING SPERM SUSPENSION IN THREE DIMENSIONS*N. Taketoshi1, T. Omori1, T. Ishikawa1
1

Tohoku University, Aramaki Aza Aoba 6-6-01, Sendai 980-8579, Japan*nanami.taketoshi.q1@dc.tohoku.ac.jp

ABSTRACT
Sperm and their motility are an important part of the fertilization process. One of the recentsocial problems is the declining birth rate, which is partly due to the increase in the number ofcouples suffering from infertility. Various factors contribute to infertility, but in recent years,
male infertility has been attracting attention in addition to female infertility. One of thesymptoms of male infertility is oligozoospermia, a condition in which the number of sperm islower than normal. Declining sperm numbers are thought to lead to lower egg encounter rates,
but recently it has also been reported that sperm motility can vary with their population. For
example, mammalian sperm have shown that bovine and mouse sperm swim in groups and that
their swimming directions are aligned. These experimental results suggest that the swimming
behavior of sperm differs between single swimming and group swimming. It is possible thatthe low sperm counts of oligozoospermia, as described above, and sperm in normal semen show
different swimming behaviors, which may affect the difference in fertilization rates. Therefore,clarifying the relationship between sperm count and swimming may help to solve infertility
problems.
In the previous hydrodynamical studies on sperm swimming have so far focused on single
sperm and two sperm (1,2), but there have been only a few simulations of sperm population
swimming (3,4). Although these studies showed sperm forming clusters or large structures, themotions of sperm cells have restricted in a plane. In reality, however, they swim in threedimensional space, and thus it is necessary to investigate how sperm behave in threedimensional space.
In this study, we tried to represent sperm swimming in more realistic by making the spermmodel swam freely in 3D space, and investigated how the swimming behavior differs when theconcentration of sperm is changed.
REFERENCES[1] Nanami Taketoshi, Toshihiro Omori and Takuji Ishikawa, “Elasto-hydrodynamic
interaction of two swimming sperm”, Physics of Fluids, 32, 101901, 2020.
[2] Toshihiro Omori and Takuji Ishikawa, PHYSICAL REVIEW E., 93, 032402, 2016[3] Kenta Ishimoto and Eamonn A. Gaffney, ”Hydrodynamic Clustering of Human Sperm in
Viscoelastic Fluids”, Scientific Reports, 8:15600, 2018[4] Simon F. Schoeller and Eric E. Keaveny,” From flagellar undulations to collective
motion: predicting the dynamics of sperm suspensions”, Journal of Royal SocietyInterface, 15:20170834, 2018

PSFVIP13-21

EXPERIMENTAL STUDY OF MOVING-TRPIV ON DRAG REDUCTIONCONTROL OF COHERENT STRUCTURES IN TURBULENT BOUNDARY LAYEROVER SUPERHYDROPHOBIC SURFACEYue Jinhui1,Wang Xinwei 1, Jiang Nan1,2
1

Department of mechanics, Tianjin University, 135 Yaguan Road, Haihe Education Park,
2

Jinnan District,, Tianjin, Tianjin 300354，China
Tianjin Key Laboratory of modern Engineering Mechanics, 135 Yaguan Road, Haihe
Education Park, Jinnan District,, Tianjin, Tianjin 300354，China

ABSTRACTThe moving TR-PIV system was used to measure the velocity fields of the turbulent boundary
layer on smooth surface and superhydrophobic surface as they moved downstream. The data
is denoised by filtering, and the fluctuating velocity signal is obtained by combining theinterpolation results of the direct numerical simulation data. It is found that the Reynolds
shear stress, flow and normal turbulence of the superhydrophobic surface in the near wallregion of the boundary layer are significantly lower than those of the smooth surface, whichindicates that the superhydrophobic surface can suppress the high Reynolds stress events inthe near wall region. Using wavelet decomposition to decompose the pulsation velocity, it isfound that the maximum energy of the flow direction of the two surfaces is located in the nearwall region, and the maximum energy scale is about 2δ. The spatial topological morphologyof the coherent structure of the eject and sweep process of the maximum energy scale was
detected separately using the conditional sampling and the spatial phase averaging methods, it
is found that the vortex structure of the large-scale eject and sweep events is a large-scalevortex packet structure composed of several small vortices, and the streamline of each small
vortex forms a local unstable dynamic system composed of saddle points and focal points.
The dynamics of sweep event on superhydrophobic surfaces are simpler and less intense. 𝜆𝑐𝑖
criterion is used to extract the vortex strength in the two surfaces, it is found that the vortex
strength of the superhydrophobic surface is obviously weaker than the smooth surface near
the wall. The number of uniform momentum zone (UMZs) on the superhydrophobic surface
is lower, indicating that the large scale coherent structures has an effect on the number of
uniform momentum zone. In the above study, the passive control of the coherent structure
was used as the starting point to explore the influence of the superhydrophobic surface on thecoherent structure. The results show that the energy of the burst coherent structure in the
turbulent boundary layer of the superhydrophobic surface is reduced, thus achieving the dragreduction effect.
REFERENCES[1] Adrian RJ, Meinhart CD, Tomkins CD. Vortex organization in the outer region of the
turbulent boundary layer. Journal of Fluid Mechanics, 2000, 422: 1-54

PSFVIP13-22

Tomographic PIV measurements in the wake ofa wall-mounted barchan dune
XiaoLei Han1, Akira RINOSHIKA1, 2(Corresponding author)
1

School of Aeronautic Science and Engineering
Beijing University of Aeronautics and Astronautics
37 Xueyuan, Haidian District, Beijing, 100191, CHINA
2
Department of Mechanical Systems Engineering
Graduate School of Science and Engineering, Yamagata University
4-3-16 Jonan, Yonezawa-shi, Yamagata 992-8510, JAPANe-mail: rinosika@yz.yamagata-u.ac.jp

Abstract
Barchan dunes with typical crescentic planform shape, commonly existing in nature,
have been widely explored due to the great potential to reduce drag. However, thedynamic characteristics of this wake field is strong three-dimensional, time-dependent,
turbulent. As such, a volumetric velocity measurement technique is required to capture
the topological evolution of these coherent vortex structures. For this purpose,
tomographic particle image velocimetry (TPIV) measurement is conducted toinvestigate flow structures behind a wall-mounted barchan dune model mostly
immersed in a laminar boundary layer in a circulation water tunnel. The instantaneous
three-dimensional arch-shaped vortex chains originating from the rear ridge of thebarchan and the typical quasi-streamwise streak induced by the internal boundary layer
development are first experimentally obtained in this work. Additionally, the time
evolution of these dominant flow structures was investigated by use of time-dependentconditional averaging, which is a necessary step in topological analysis within thecomplex flow. Nevertheless, both conditionally averaged and typical instantaneous
three-dimensional flow fields all provide credible proof for the fact that arch-shaped
vortex populates the barchan dune wake, and the inclination angle of these structuresaligned with the streamwise direction will decrease when advecting downstream. These
results provide a comprehensive picture for us to understand the law of the temporal
behavior of three-dimensional unsteady coherent flow structures within the wake fieldsof the barchan dune.
Key words: dynamic characteristics, arch-shaped vortex, vortex evolution

PSFVIP13-23

REVERSAL MOTION OF THE SOLID PARTICLES WITH HIGH
THERMAL CONDUCTIVITY IN THE SOLID-DISPERSEDRAYLEIGH-BÉNARD CONVECTION
Dai SHI*1
1

Department of Mechanical Engineering, Osaka University, 2-1 Yamada-oka, Suita-City,
Osaka 565-0871 Japan*shi@fluid.mech.eng.osaka-u.ac.jp
ABSTRACTThe liquid-solid multiphase Rayleigh–Bénard (RB) system is one of the most typical nonequilibrium hydrodynamic systems in nature and industry, while most studies on granular
flow in the multiphase RB system simplify the influence of thermal coupling from the solid
phase to the fluid, viewing them as isothermal particles. The temperature gradient within thesolid phase is studied by Takeuchi et al [1], and a regular oscillation mode of the granular
flow is predicted to appear when the heat conductivity ratio between the solid and liquid
phase increases to more than 101. A reversal mode is also predicted to exist when theconvection in the same RB system becomes stronger [2].
In this study, an original experimental method to replace the vertical gravitational acceleration
with a horizontal centrifugal acceleration is developed to reproduce the multiphase RB system
in reality. The heat conductivity ratio between the solid and liquid phase is set to be 83.7 tohighlight the influence of thermal coupling from the particles to the fluid. Experiments under
the condition of Rayleigh number (Ra) = 2.7×104, 5.6×104, 1.1×105 in a square, closed RB
system is carried out to observe the change in particle motion.
It is found that most particles remain stationary because of the static friction force in thesystem, even when Ra increases from 2.7 × 104 to 1.1 × 105 by varying the temperature
difference between the hot and cold end of the RB system from 5K to 30K. However, somefloating particles are found to show an obvious, coherent flow pattern of “reversal” under the
Ra condition of 2.7 × 104. This large-scale “reversal” pattern survives even when the Ra
increases to 1.1×105.
A physical explanation for this reversal phenomenon is attempted based on the particle
mechanical and thermal coupling with the fluid. The imbalance in buoyancy momentum isbelieved to be the key to explain for the occurrence of the reversal phenomenon.
REFERENCES[1] Takeuchi S. et al, “Effect of temperature gradient within a solid particle on the rotationand oscillation modes in solid-dispersed two-phase flows”, International Journal of Heatand Fluid Flow, 43 (2013) 15-25.
[2] Takeuchi S. et al, “Flow reversals in particle-dispersed natural convection in a twodimensional enclosed square domain”, Physical Review Fluids, 084303 (2019) 1-22.

PSFVIP13-24

NEAR-LIMITING BEHAVIOR OF POOL FIRES WITH STRONG SWIRLING
FLOW*K. Tsukamoto1, A. Odawara1, T. Yamazaki1, T. Matsuoka1 and **Y. Nakamura1
1

Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi 441-8580
Japan*tsukamoto.keita.kj@tut.jp; **yuji@me.tut.ac.jp

ABSTRACT
Near-limit dynamic behavior of non-premixed flame formed over the ethanol pool fires withprescribed swirling flow using rotational mesh screen has been examined experimentally.
Experimental parameters were the diameter of the pool and the rotational speed of the meshscreen. Rotational mesh is hanged over the ceiling with rotor and its deformation during therotation is prevented using the circular guide. In this way, the rotation axis is quite solid even
we employed the high-speed of rotation; this enables us to investigate the near-limiting flame
behavior at high circulation condition. Flame dynamics was recorded by the digital video
camera and binary image of the flame is analyzed to capture the flame behavior character
depending on the swirling flow.
It was experimentally confirmed that the flame height varies 1/3 power of the imposed
circulation as suggested by the past works for various size of fire whirls [1-3]. However, it isclearly identified the trend does not sustain when higher circulation is imposed, especially withthe smaller pools. Such critical conditions strongly depend on both pool diameter and thecirculation. With careful observation and analysis, repetitive motion in the flame height in time
(namely, large fluctuation of the flame dynamics) has been identified. With small-pool flame,
the flame diameter is originally small. Once the circulation flow field is imposed, the flame
responds to be narrower to form smaller flame diameter along the axis. Because the chemical
reaction is finite process in time (even it is fast enough in some sense), too-small flame diameter
is not possible to present, namely, local extinction shall occur. Once this happens (with strong
circulation field), flame is suddenly “terminated” and the flame height is abruptly shorter.
However, the unburned gas will remain in downstream due to the local extinction as described,
re-ignition may occur once the condition is relaxed. In this way, the flame height may appear
suddenly larger. Such local extinction and re-ignition may result in appearance of repetitive
behavior of the flame dynamics as observed. At present, we are attempted to summarize thecritical condition to appear the fluctuation by means of local extinction theory.

REFERENCES[1] Kuwana, K., Sekimoto, K., Saito, K., and Williams, F.A., “Scaling Fire Whirls”, Fire
Safety Journal Vol. 43 (2008), pp. 252-257.
[2] Lei, J., Liu, N., and Zhang, L., “Experimental Research on Combustion Dynamics ofMedium-scale Fire Whirl”, Proceedings of The Combustion Institute Vol. 33 (2011), pp.
2407~2415.
[3] Hartl, K.A., and Smits, A.J., “Scaling of A Small-scale Burner Fire Whirl”, Combustion
and Flame Vol. 163 (2016), pp.202-208.

PSFVIP13-25

UNSTEADY FLOW INSTABILITY BETWEEN TWO PARALLEL CIRCULAR
PLATES IN POWER GENERATOR*Naho Kishizawa1, Itsuro Honda2, Naohisa Takagaki2 and Osamu Kawanami2
1

Graduate student, University of Hyogo, 2167, Shosha, Himeji city, Hyogo 671-2201 Japan*ep18b034@steng.u-hyogo.ac.jp
2
School of Eng., University of Hyogo, 2167, Shosha, Himeji city, Hyogo 671-2201 Japan

ABSTRACTThe electric generator has a weak point that electric energy is converted into heat energy.
Cooling parts is important for safe operation, as high temperatures in parts can destroy themachine. A gap between two parallel circular plates regarded the cooling part of the electric
generator, unstable flow velocity occurs. The reason this phenomenon is caused is unexplained.
The purpose of this study is that the result of PIV experiments and that of numerical calculations
is compared. In this paper, radial flow and tangential flow in the gap between two parallel
circular plates was performed by PIV experiment and numerical simulation. In the experiment,
two parallel circular plates having a diameter of 200 mm were used. The two-dimensional
velocity field measured in the center plane of the wall-normal-span. In the numericalcomputations, high order finite difference scheme is applied to the Navier-Stokes equations.
The numerical simulation was conducted over the wide Re numbers. Computational results
showed the unsteady velocity field as the Re number rise to 10000. The computational results
were animated to observe the unsteady state. From this animation, the frequency of the unsteadyphenomenon between two parallel circular plates was obtained. The Re=10000, in which an
instability region appeared in this study, is almost the same as Orszag’s critical Reynolds
number Rec=5772. These results show that the unsteady flow is rotating more slowly than theinlet rotation based on the inlet tangential velocity. The important findings are that unsteadyflow obtained here is rotating stall similar to the vaneless diffuser of the centrifugal fan. As Re
number increases, the shear layer was formed between inner boundary of the plate and thestationary its outer fluid. Therefore, rotating stall observed here is interpreted by the KelvinHelmholtz instability at shear layer.
REFERENCES[1] Orszag, S. A., J. Fluid Mech, Vol. 50 (1971), pp.689-703[2] G. K. Batchelor, An Introduction to Fluid Dynamics, Cambridge University Press, (1967),
Chap. 7.

PSFVIP13-26
3D WAVELET TRANSFORM ON FLOW STRUCTURES BEHIND A WALLMOUNTED SHORT CYLINDER WITH A FRONT INCLINED HOLE
H. Rinoshika
Yamagata University, 4-3-16 Jonan, Yonezawa-shi, Yamagata 992-8510, Japanhrinoshika@gmail.com

ABSTRACTThis paper deals with the three-dimensional (3D) wake structures of a wall-mounted shortcircular cylinder, which are controlled by the flow issuing from a front inclined hole (FIH)
drilled from the front side surface to the free end surface in the short cylinder. The 3D velocity
fields are instantaneously measured at a Reynolds number of 10720 based on high-resolution
tomographic particle image velocimetry (Tomo-PIV) in a water tunnel. The 3D velocity fields,
Q criterion, tip vortices, and arch-type vortex are compared between the FIH cylinders and astandard cylinder. A 3D W-type arch vortex is observed behind the short FIH cylinder.
Compared with the standard cylinder, the 3D W-type arch vortex exhibits a large peak orconvex at center of the horizontal part and collapses more rapidly at the downstream for theFIH cylinders. The flow from the FIH may increase the rear recirculation region, and its height
may effectively control the vortical structures. A 3D wavelet multiresolution analysis isemployed to decompose the instantaneous 3D velocity fields measured by the Tomo-PIV. The
large-scale streamwise vortices in the FIH cylinder wakes are smaller than those in the standard
cylinder wake, and this becomes more evident as the hole height increases. However, 3D timeaveraged large-scale arch vortical structures becomes stronger.
Keywords : 3D wavelet transform, Arch vortex, Flow control, Tomographic PIV, Vortex, Wake,
Wall-mounted short cylinder

PSFVIP13-28

VISUALIZATION OF THERMAL NETWORKS IN LAYERED STRUCTURES BY
MEANS OF PUMP-PROBE AND DECONVOLUTION TECHNIQUE*T. Silveira Joao Vitor1, H. Daiki1 and F. Kazuyoshi1
1Tokyo Institute of Technology, Meguro-ku, Oookayama, 2-12-1, i6-3, 152-8850 Japan*thomsen.j.aa@m.titech.ac.jp
ABSTRACTIn thermal management of electronics, the thermal parameters of components, such as thejunction-to-case or junction-to-ambient thermal resistances are necessary for adequate thermal
characterization of semiconductor packages. To estimate such parameters, the network
identification by deconvolution method (i.e., NID) is widely applied in the semiconductor
industry. Commonly, the NID method uses the thermal response obtained from inside thepackage (e.g., heat generation in the semiconductor die) to characterize the test subjects. In thiscontext, the present work investigates the practical aspects of applying NID to the thermal
characterization of electronics from an external excitation source.
The NID method consists of obtaining the time constant spectrum (i.e., TCS) of a given system
by deconvolving its thermal response from a weight function. Further transformations utilizing
the TCS allow for the construction of the structure function relative to the device under test,
which maps the heat flow path from the source to the heat sink. This technique enables theidentification of the thermal resistances in the system.
To achieve NID from an outside excitation, the temperature transients used as input for the NID
are measured with the pump-probe transient thermoreflectance method (i.e., PPTTR). Thismethodology consists of using two lasers. The pump laser is applied to excite the sample, while
the probe laser provides a signal to be measured by a photodetector. Thus, the reflectancetransients obtained from the photodetector provide the thermal response used in the NID.
By employing heat transfer simulations, this investigation goes into detail about the theoricalaspects of using NID from an external excitation. Experimentally, the thermal characterizationof a thin film on the order of 100 nm on a substrate was successfully carried, which highlights
the potential of the methodology to determine the thermal resistances of layered structures, suchas semiconductor dies, from external excitation.
REFERENCES[1] Székely, V. and Van. B. T., “Fine structure of heat flow path in semiconductor devices: A
measurement and identification method”, Solid-State Electronics, Vol. 31, No. 9-(1988),
pp. 1363-1368.
[2] Y. Ezzahri and A. Shakouri, "Application of network identification by deconvolution
method to the thermal analysis of the pump-probe transient thermoreflectance signal",
Review of Scientific Instruments 80, 074903, (2009), https://doi.org/10.1063/1.3176463

PSFVIP13-29
VISUALIZATION OF MIXING AND FLOW STRUCTURE IN BLADE-FREE
PLANETARY MIXER WITH FREE SURFACE*T. Yamagata1, K. Sato1, and T. Igarashi1
1

Niigata University, 8050 Ikarashi 2-Nocho, Nishi-ku, Niigata, Niigata 950-2181 Japan*yamagata@eng.niigata-u.ac.jp

ABSTRACT
Blade-free planetary mixer can agitate a liquid without a mixing blade by a flow induced by aprecession of the container. The precessing flow is realized by the combined effect of therotation of the container around an axis and the revolution around an off-axis distance awayfrom the container. Clarifying the flow structure and mixing mechanism inside the container isnecessary for improving mixing performance. In the precessing cylinder filled with fluid, flow
instability increases [1] and the vortical structures are found to be in spiral forms [2]. The
inclination and distortion of the rotation axis increases at a certain precession rate, at which themixing performance increases [3][4]. These studies focused on flow structures in a liquid-filled
cylinder. Therefore, the information on the flow structure with the free surface is insufficient,which is found in actual mixer use. The objective of this study was to investigate the flow
structure and mixing performance in a precessing cylinder with a free surface of the fluid. The
flow structure and mixing performance were numerically investigated with an unsteady-statesolver for incompressible flows of Newtonian fluids and the volume-of-fluid method. The
numerical results were validated by comparison with flow visualization experiments of mixing
from particle dispersion. The precessing cylinder with a free surface increased mixing
performance at a higher precession rate than liquid filled case. The deformation of the axis of
the swirling flow due to the inclination of the free surface resulted a change in the precession
rate that increased the mixing performance. The angle of the cylinder strongly affected themixing performance, while the liquid level height in the cylinder and revolution radius had aminor effect.
REFERENCES[1] Lagrange, R., Meunier, P., Nadal, F., Eloy, C., “Precessional instability of a fluid cylinder”,
Journal of Fluid Mechanics, Vol. 666 (2011), pp. 104-145.
[2] Chergui, N., Lateb, M., Lacroix, E., Thermo, L. D., “CFD study of flow dynamics in a
blade free planetary mixer (BFPM) – A qualitative flow study”, Chemical Engineering
Research and Design, Vol. 102 (2015), pp. 100-115.
[3] Yamagata, T., Fujisawa, N., “Effect of Rotation and Revolution on Performance of BladeFree Planetary Mixer”, Journal of Flow Control, Measurement & Visualization, Vol. 7(2019), pp. 1-10.
[4] Yamagata, T., Sugisawa, H., Fujisawa, N., “Experimental study on laminar mixing inplanetary mixer”, Experiments in Fluids, Vol. 62 (2021), 28 (12 pages).

PSFVIP13-30

EXPERIMENTAL INVESTIGATION ON FLOW CHARACTERISTICS AND HEATTRANSFER OF NONCIRCULAR SYNTHETIC JETS
L. Wang1, *L.H. Feng1, Y. Xu1 and J.J. Wang1
1

Fluid Mechanics Key Laboratory of Education Ministry, Beijing University of Aeronautics
and Astronautics, Beijing 100191 China*lhfeng@buaa.edu.cn

ABSTRACTThis study reveals the flow characteristics and heat transfer of noncircular synthetic jets throughstudying their interaction with a cross-flow [1] and a heated wall [2]. For the interaction with across-flow, tomographic particle image velocimetry (PIV) is used to measure the flow field ofa rectangular synthetic jet with aspect ratio (AR) of 3 interaction with a laminar boundary-layer.
Two orifice orientations (spanwise and streamwise) are examined at a synthetic-jet to freestream velocity ratio of 1. The results display complex three-dimensional vortical structures
and axis switching of vortex rings. Due to axis switching, the spanwise configuration yields
vortical structure interaction, causing faster jet transition and lower velocity deficit than thestreamwise case. In addition, a stronger spanwise vortex in the near-wall region is induced by
the spanwise configuration, which transfers more momentum and initial disturbance into theboundary layer, suggesting greater efficiency of promoting boundary-layer transition. For the
impingement onto a heated wall, thermographic phosphor thermometry and two-dimensional
PIV are used to acquire the wall temperature and flow field, respectively. Five orificeconfigurations (circular, square, AR = 3 elliptic, and AR = 3 and 5 rectangular) are examinedat an orifice-to-wall distance of 7.5. The results demonstrate heat transfer enhancement of
impinging synthetic jets using noncircular orifices. The square orifice displays better stagnation
cooling performance due to the larger impinging velocity and deeper penetration into the wall
shear layer. The elliptic and rectangular orifices display axis-switching of vortex rings before
they impinge onto the wall, which enhances the near-wall mixing and turbulent kinetic energy
and thus heat transfer compared with the circular case. In particular, strong secondary structuresin the trailing jet are induced by the AR = 5 rectangular orifice, resulting in the double-peak
distribution of wall temperature in the major-axis direction. Furthermore, the AR = 5
rectangular orifice yields a stronger wall jet in the minor-axis direction. As a result, the AR = 5
rectangular orifice achieves the optimal cooling performance with the maximum time-averaged
cooling area.
REFERENCES[1] Wang, L., Feng, L.H., “The interactions of rectangular synthetic jets with a laminar crossflow”, Journal of Fluid Mechanics, Vol. 899, (2020), A32.
[2] Wang, L., Feng, L.H., Xu, Y., Xu, Y., Wang, J.J., “Experimental investigation on flow
characteristics and unsteady heat transfer of noncircular impinging synthetic jets”,
International Journal of Heat and Mass Transfer, Vol. 190, (2022), 122760.

PSFVIP13-31
VISUALIZATION OF A FRESHWATER-SPONGE SNEEZING*Kei Kawashima1, Kenji Kikuchi1, Takuji Ishikawa1
1

Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 Japan*kei.kawashima.s8@dc.tohoku.ac.jp

ABSTRACT
Sponges, which are sessile animals and widely distributed under water, take a filter feeding
using flagellar beat in the choanocytes. Choanocytes are the cells in the body of a sponge that
undertake both pumping and filtering functions. Filter feeding of sponges accumulates theorganic particles, which is one of the sources of water pollution[1]. Hence, sponges play a rolein purifying water in nature[2]. Interestingly, sponges can clear clogged incurrent canal by asneezing-like behavior in spite of having no muscles or nerves[3]. In order to apply the sponge’s
filtration function to engineering filter systems, we investigated sneeze-like discharge behaviors
that support the constant water purification action of sponges.
To induce sneezing, we compared the sneezing frequency of a sponge in different amounts ofdissolved oxygen in the culture medium, and found that the frequency of sneezing was
predominantly greater for a sponge in the medium with less dissolved oxygen.
Previous studies have induced sneezing by applying mechanical agitation to a sponge or byadding amino acids such as GABA and L-glutamate[4]. In the current study, we newly foundthat the sponge increases the frequency of sneezing by decreasing the concentration of dissolved
oxygen. This suggests that a sponge may perceive a decrease in oxygen concentration as anincurrent canal blockage.
We fed the cultured sponge with fluorescent particles and took time-lapse photographs, whichshowed that the sponge sneezed, but the number of particles in their bodies did not change after
the sneeze. However, we succeeded in observing particles transported from the choanocytes tothe amoebocytes during the sneezing.
This study suggests that the sneezing behavior of a sponge may not only backflow water toclear the incurrent canal, but may also help transport small particles from choanocytes toamoebocytes.
In the future, we intend to measure discharging effects of sneezing and develop a mathematicalmodel of the constant water purification action of a sponge that takes into account the sneezing
and other particle emission behaviors.
REFERENCES[1] Steven E. McMurray, Zackary I. Johnson, Dana E. Hunt, Joseph R. Pawlik, Christopher
M. Finelli, Selective feeding by the giant barrel sponge enhances foraging efficiency,
Limnology and Oceanography, Vol. 61, (2016), pp.1271-1286[2] Nathan Grant, Eugueni Matveev, Amanda S. Kahn, Sally P. Leys, Suspended sedimentcauses feeding current arrests in situ in the glass sponge Aphrocallistes vastus, Marine
Environmental Research, Vol. 137,(2018), pp. 111-120[3] Glen R. D. Elliot, Sally P. Leys, Evidence for glutamate, GABA and NO in coordinating
behavior in the sponge, Ephydatia muelleri (Demospongiae, Spongillidae), The Journal of
Experimental Biology, Vol. 213, (2010), pp. 2310-2321[4] Kornelia Ellwanger, Andre Eich, Michael Nickel, GABA and glutamate specificallyinduce contractions in the sponge Tethya wilhelma, Journal of Comparative Physiology,
Vol. 193,(2006), pp. 1-11

PSFVIP13-32

INFLUENCE OF SYNTHETIC JET ON MULTISCALE CHARACTERISTICS IN
WALL-BOUNDED TURBULENCE*Biaohui Li1 and Nan Jiang2
1

School of Mechanical Engineering, Tianjin University,135 Yaguan Road, Jinnan District,Tianjin 300354, China*libiaohui915@outlook.com
2
Tianjin Key Laboratory of Modern Engineering Mechanics, 135 Yaguan Road, Jinnan
District, Tianjin 300354, China

ABSTRACTThe research focuses on the impacts of synthetic jet on a fully-developed turbulent boundary
layer (TBL), particle image velocimetry (PIV) system is utilized to capture the two components
velocity signals in the flow field. The near-wall mean velocity profile obtained by single-pixel
ensemble correlation (SPEC) [1] algorithm evidence the decline of streamwise velocity gradientin the range of about 30~60mm downstream of the synthetic jet outlet, achieving an average
drag reduction rate of 19.05%. In addition, under the upwash action of synthetic jet, streamwise
vortices is lifted, the activity of the near wall turbulence fluctuation is reduced.
Proper orthogonal decomposition (POD) [2] analysis reveals that the injection of the perturbation
notably attenuates the induction effect of prograde vortex on the low-speed fluid in the largescale fluctuation velocity field, thereby weakening the bursting process of near-wall turbulent
events related to the skin-friction drag. The power spectral densities of the time coefficients fordifferent mode indicate that the synthetic jet redistributes the turbulent kinetic energy, and theenergy is concentrated to the small-scale coherent structure.
The time coefficients are decomposed into signals of different frequency bands by the methodof complementary ensemble empirical mode decomposition (CEEMD) [3], it is found that thesignal is transferred from low-frequency to-high frequency due to disturbance, thus revealing
the relationship between scale and frequency band. Then, a new method of scale decomposition
is proposed, that is, the high-frequency noise data is eliminated by the continuous mean squareerror (CMSE) [4] criterion, and the large-scale fluctuation velocity field can be obtained.
REFERENCES[1] Sugisaki, H., Lee, C., Ozawa, Y., Nakai, K., Saito, Y., Nonomura, T., Asai, K. and Matsuda,Y., “Single-pixel correlation applied to background-oriented schlieren measurement”,
Experiments in Fluids, Vol. 63, No. 1 (2022), pp. 1-7.
[2] Taira, K., Hemati, M. S., Brunton, S. L., Sun, Y. and Yeh, C. A., “Modal Analysis of Fluid
Flows: Applications and Outlook”, AIAA Journal, Vol. 58, No. 11 (2019), pp. 1-25.
[3] Yeh, J. R., Shieh, J. S. and Huang, N. E., “Complementary Ensemble Empirical Mode
Decomposition: A Novel Noise Enhanced Data Analysis Method”, Advances in Adaptive
Data Analysis, Vol. 2, No. 2 (2010), pp. 135-156.
[4] Wu, H., Fang, Q., Peng, Y., Gong, Z. M. and Kong, X. Z., “Hard projectile perforation on
the monolithic and segmented RC panels with a rear steel liner”, International Journal of
Impact Engineering, Vol. 76 (2015), pp. 232-250.

PSFVIP13-33

STUDY OF UNDEREXPANDED SUPERSONIC JETS FROM AXISYMMETRICMICRO-NOZZLES IN LOW REYNOLDS NUMBER REGIONS*T. Tashiro1, S. Nakao1, Y. Miyazato1 and Y. Ishino2
1

The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, 808-0135 Japan* c1mba013@eng.kitakyu-u.ac.jp
2
Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan

ABSTRACT
There is a significant interest in studying shock-containing microjets due to the numerous
applications such as the cooling of micro-electro mechanical systems, fine particle removal ininkjet printer heads, and so on. It has been challenging issues to investigate experimentally theshock structure in the near-field region of supersonic microjets. However, recently, Sugawara
et al. [1] captured experimentally the fine structure of a shock-containing microjet issued froman axisymmetric convergent round nozzle with an inner diameter of 1000 m at the exit by theMach-Zehnder interferometer. Tashiro et al. [2] investigated experimentally the density field of
a Mach 1.5 supersonic microjet by the Twyman-Green interferometer. In the present study,
flow structure of supersonic microjet at low Reynolds numbers are investigated by the
Reynolds-averaged Navier-Stokes (RANS) simulations. Typical two turbulence models
including the Menter k- shear-stress transport (SST) and the Spalart Allmaras (SA) are used
for the simulations because they have been widely used and trusted models in areas of aerospacecommunity. Flow fields of jets issued from an axisymmetric convergent-divergent micronozzle with a Mach number of 1.5 and an inner diameter of 1000 m at the exit are simulated
by solving the RANS equations. In simulations, the nozzle pressure ratio (NPR), which isdefined as the ratio of the stagnation pressure, pos, just upstream of the nozzle to the backpressure, pb, is held constant at NPR = 4.0, but both the pos and pb are changed simultaneously
to vary the Reynolds number estimated using the diameter and flow properties at the nozzle
exit. Simulations are validated by a quantitative comparison with the jet density field obtained
previously using the Twyman-Green interferometer [2]. Effects of the Reynolds numbers on the
microjet structure are demonstrated with the density fields of the jet and Mach number contours
on the cross-sectional area including the jet centreline. The density fields simulated using the
SST and SA turbulence models are in good quantitative agreement with each other and theyshow a reasonable agreement with the experimental density field. Effects of the Reynolds
number on the near-field shock system of the microjets are clarified numerically.
REFERENCES[1] Sugawara, S., Nakao, S., Miyazato, Y., Ishino, Y. and Miki, K., “Three-Dimensional
Reconstruction of a Micro Jet with a Mach Disk by Mach-Zehnder Interferometers”, J.
Fluid Mechanics, Vol. 893, (2020), A25.
[2] Tashiro, T., Nakao, S., Miyazato, Y. and Ishino, Y., “Preliminary Experiments ofSupersonic Microjets by TGI, Proceedings of 33rd International Symposium on SpaceTechnology and Science, (2022).

PSFVIP13-34
NUMERICAL SIMULATION OF MASS TRANSFER AND VELOCITY IN TJUNCTION PIPING SYSTEM
Shun Watanabe1, Ryo Morita1, *Masaaki Satake1 and Takayuki Yamagata2
1

Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Kanagawa, 240-0196
Japan*m-satake@criepi.denken.or.jp
2
Niigata University, 8050 Ikarashi 2-Nocho, Nishi-ku, Niigata, Niigata 950-2181 Japan

ABSTRACT
Prediction and management of pipe-wall thinning in fossil and nuclear power plants areimportant for safety management and stable supply of electricity. One of the main causes of thepipe-wall thinning is flow accelerated corrosion (FAC) [1], which is a mass transfer
phenomenon from the pipe-wall surface into the fluid. Its management has been conducted withconservative evaluation of the thinning rate and the residual lifetime of the piping based on thewall thickness measurements. However, noticeable case of the wall thinning was occurred inbranch and junction piping (T-junction pipe). It is a problem to manage the section beneath thereinforcing plate of the T-junction pipe; the region where measurement is difficult to conduct
with ordinary ultrasonic testing device. Numerical analysis for the T-junction pipe wasconducted, and the wall thinning profile due to the FAC was evaluated by calculating the masstransfer coefficient[2]. In this study, numerical simulation with the same methods[2] isconducted to investigate the influence of the flow rate ratio of the main pipe and branch pipeon the mass transfer and velocity field in T-junction pipe. The mass transfer coefficient of theexperiment showed two peaks after the main pipe and the branch pipe merged. The maximum
value increased as the flow rate from the branch pipe increased. These results are in qualitative
agreement with the experimental results. From these results, the validity of the numericalsimulation methods[2] is confirmed.
REFERENCES[1] Sanchez-Caldera, L.E., Griffith, P., Rabinowicz, E., “The mechanism of corrosion-erosion
in steam extraction lines of power stations”, ASME Journal of Engineering for Gas
Turbines and Power, Vol. 110 (1988), pp. 180-184.
[2] Watanabe, S., Morita, R., “Characteristic of pipe wall thinning by flow accelerated
corrosion at drift region in junction piping”, Transactions of the JSME, Vol. 86 (2020), 2000110 (16 pages).

PSFVIP13-35
INERT GAS FLOW RELEASED FROM BURSTING SAUSAGE-SHAPED RUBBERBALLOON AND ITS EXTINGUISHING CHARACTARISTICS*A. Hinako Mikami and B. Hiroyuki Torikai
Hirosaki University, Bunkyo Town 1, Hirosaki, Aomori 036-8560 Japan*A.h21ms540@hirosaki-u.ac.jp and B.torikai@hirosaki-u.ac.jp

ABSTRACTAn inert gas is one of clean and environmentally friendly gaseous extinguishing agents.
Basically, the inert gas is supplied to fire area as a high velocity jet and easy to mix with air.
As a result, it is difficult to deliver the inert gases over long distances without its concentration
reduction. The authors have proposed to use a rubber balloon for transporting of gaseousextinguishing agents [1,2]. When an inert gas is filled into a rubber balloon, the rubber
membrane does not allow contact the inert gas with an ambient gas, and we can easily carryand deliver the extinguishing capsule to combustion region while maintaining the highconcentration. Moreover, when a rubber balloon contacts with a diffusion flame, it bursts
instantly, and then the inert gas filled in it is released to the flame at high speed and close range.
As a result, fires are considered to be extinguished without the need for large amounts of theinert gas by using the rubber-balloon extinguishing method.
In this study, in order to clarify the extinguishing characteristics, the authors have carried out
the extinguishing experiments of a methane-air diffusion flame formed on a round porous
burner using a sausage-shaped rubber balloon filled with nitrogen gas. The sausage-shaped
rubber balloon was transported at an arbitrary speed to the extinguishing target using an electriclinear slide actuator. To measure the extinguishing effectiveness, an extinguishing probability
was measured varying the transporting speed of the rubber balloon and the height of the rubber
balloon from the burner surface. To elucidate the extinguishing mechanisms, the released flowfrom the bursting balloon was visualized with a laser light sheet method. Furthermore, thecomparisons of the extinguishing effectiveness and the released flow behaviours between thesausage-shaped and elliptical-shaped rubber balloons were done.
From the experimental results, it is found that the sausage-shaped rubber balloon always has
the higher extinguishing effectiveness than the elliptical-shaped rubber balloon because thenitrogen gas flow released from the sausage-shaped rubber balloon is more effectively supplied
to the flame base of the diffusion flame. This means that the sausage shape is thought to besuitable as a fire-extinguishing capsule.
REFERENCES[1] Hiroyuki Torikai, Extinguishing Characteristics of a Pool Fire with a Rubber Balloon
Filled with Inert Gases. Fire Technology, Vol. 56, pp.385-399 (2019).
[2] Yasushi Iwatani and Hiroyuki Torikai, Improvement of Fire Extinguishing Performanceby Decentralized Supply of Fire-Fighting Agents, Open Journal of Safety Science andTechnology.Vol.7, pp.87-95 (2017).

PSFVIP13-37

THE FIBER-ORIENTATION OF CELLULOSE NANOFIBER SUSPENSIONS IN A
PLANAR EXPANSION FLOW
*A. Kusano1, A. Ushida2, and T. Sato3
1

Graduate school of Science and Technology, Niigata University, 8050, 2-no-cho, Ikarashi,
Nishi-Ward, Niigata City, 950-2181, Japan*f21b080h@mail.cc.niigata-u.ac.jp
2
Faculty of Engineering, Niigata University, 8050, 2-no-cho, Ikarashi, Nishi-Ward,
Niigata City, 950-2181, Japan
3
Institute for Research Promotion, Niigata University, 8050, 2-no-cho, Ikarashi, NishiWard, Niigata City, 950-2181, Japan
ABSTRACTTEMPO-oxidized cellulose nanofiber (CNF) [1] is one of the materials expected be applied invarious fields. In this study, we investigate the fiber-orientation of CNF suspensions to apply it
as reinforced resin composite materials by injection molding. In recent years, items moldedfrom plastic are mass produced and increasing [2], then they are discarded. CNF is a fiber which
has biodegradable; therefore, it can be an environmentally friendly raw material for composites.
To practicalize CNF as a composite, it is crucial to understand how flow influences both thedirection and degree of orientation of fibers. Because the fiber orientation induced by flow inthe molding process affects the properties of molded items. In fiber suspension, fibers occur
mechanical interference such as entanglement as increasing. In molding flow, we have known
that glass or carbon fiber is much larger than polymer of matrix so that flow field, other fibers,
and mold cause mechanical interference with each fiber [3]. Flows with abrupt expansions
occur often during mold processing. However, only a few studies have been conducted on theflow of CNF suspensions through a planar expansion flow. Thus, the fiber-orientation of CNF
suspensions in these complex flow fields is yet to be elucidated. The aim of this study is toanalyze the flow-induced orientation of CNF suspensions in a planar channel with an abrupt
expansion. To achieve this, flow-induced birefringence was used. Since birefringence iscorrelated with the strength of the fiber-orientation, high birefringence indicates a highlyoriented fiber state. As the result, the birefringence is rapidly decreased at the abrupt expansion
but after that it drastic increasing. Thereafter, the birefringence gradually decreased andindicated an approximately constant value. These phenomena qualitatively did not depend on
the flow rates qualitatively. The results of this study suggested that the strength of fiber
orientation depends on the flow rates but is not affected by the flow rate with respect to theorientation fields.
REFERENCES[1] Saito, T., Kimura, S., Nishiyama, Y., Isogai, A., “Cellulose Nanofibers Prepared by
TEMPO-Mediated Oxidation of Native Cellulose”, Biomacromolecules, Vol. 8, (2007),
pp. 2485-2491.
[2] Geyer, R., Jambeck, J.R., Law, K.L., “Production, use, and fate of all plastics ever made”,
Science Advances, Vol. 3, No 7 (2007), e1700782.
[3] Kiziltas, A., Nazari, B., Gardner, D.J., Bousfield, D.W., “Polyamide 6–Cellulose
Composites: Effect of Cellulose Composition on Melt Rheology and Crystallization
Behavior”, Polymer Engineering & Science, Vol. 54, No. 4 (2014), pp. 739-746.

PSFVIP13-39

INFLUENCE OF THE PERIODIC FLOW ON THE FLOW STRUCTURE AROUND
THE ROBOTIC FISH.
*M. Kawano1, Y. Tanaka2 and Y. Isoda1
1Graduate School of Science and Technology, Kyoto Institute of Technology,
Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
2
Faculty of Mechanical Engineering, Kyoto Institute of Technology,
Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan*m1623106@edu.kit.ac.jp

ABSTRACTIn this study, we investigate the influence of the difference between periodic and steady flowon Q value and the surface pressure of the robotic fish. We conducted calculations of the flow
around the robotic with open-source computational fluid dynamics (CFD) software
OpenFOAM. In this study, the Reynolds number is about 15600, and the mean velocity is 0.04
[m/sec]. A periodic flow is a flow in which the velocity varies sinusoidally in the freestream
direction. The robotic fish is composed of three sections: front as body, middle as actuated tail,and rear as caudal fin. The front section is fixed, and the middle and rear sections are oscillating.
Each oscillating section is controlled its angle sinusoidally. In steady flow, the time-average lift
coefficient is almost zero. In contrast, it is non-zero in a periodic flow.
We visualize the Q value to investigate the vortex structure to reveal the difference from theflow field. Moreover, we investigate the surface pressure of the robotic fish to reveal the
influence of the pressure field. The pressure gradient of a periodic flow causes changing theflow velocity in the flow direction. It is difficult to understand the pressure change on thesurface of the robot. So, we subtract the pressure caused by a periodic flow from the pressure
field. From the isosurface of the Q-value, the vortex behind the robotic fish is symmetric in a
steady flow with respect to the flow direction. However, in a periodic flow, it is asymmetricwith respect to the flow direction with a larger vortex on one side. Comparing the surfacepressure between steady and periodic flow, the amplitude of pressure in periodic flow is smaller
than that of the pressure in steady flow on the same side as Q-value. In this way, the steady andperiodic flow are different flow fields on one side of the robotic fish.

REFERENCESPSFVIP13-41
FLOW BOILING HEAT TRANSFER IN A PLATE HEAT EXCHANGER WITHMIXED CHEVRON ANGLE PLATES
Mu-Ting Hsieh, Chien-Yuh Yang* and Fu-Chen Lin
National Central University, No. 300, Jhongda Rd., Jhongli, Taoyuan 32001, Taiwan*cyyang@ncu.edu.tw

ABSTRACT
Plate heat exchangers (PHE) have been widely used in refrigeration and air conditioning system,
chemical reaction processes and many other industrial applications. While applying the plate
heat exchanger as an evaporator in an air-condition system, refrigerant flows into the heatexchanger at two-phase condition. Since the length of flow path the in the channels near the
inlet port is shorter than that in the channels farther away from the inlet port, most of the fluid
will flow through the channels closer to the inlet. This will cause a flow maldistribution anddegrade the heat exchanger performance.
This study provides an experimental investigation of refrigerant R-410A boiling in a brazed
plate heat exchanger with mixed chevron angle plates. 60 plates with 65o chevron angle wereused in the first half and the other 60 plates 35o used in the second half to compose a 120 plates
PHE. Since the flow resistance in the lower chevron angle plates is smaller than it in the higher
chevron angle plates, it is expected to reduce the difference of flow resistance between theseparts and relieve the flow maldistribution of two-phase flow in a multi-plates PHE.
Infrared (IR) thermography was used to observe the PHE side temperature distribution. The
observation results showed that the temperature uniformity was improved at low Reynolds
conditions by applying mixed chevron angle plates. While Reynolds is high, there is no
significant difference of temperature distribution for these two heat exchangers. The heattransfer coefficient in the mixed chevron angle plates PHE is 5.8% higher than that in the singlechevron angle PHE and the pressure drop is 22.9% lower. The overall heat exchanger
performance has been significantly improved by the mixed chevron angle design.

PSFVIP13-43

CFD ANALYSIS AND VISUALIZATION OF CAVITATING BUBBLY FLOWSTRUCTURE IN A CENTRIFUGAL PUMP USING MULTI-PROCESSCAVITATION MODEL* Akihisa Yamada1, Taiki Takamine2, Shin-ichi Tsuda2 and Satoshi Watanabe 2
1

Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka,
819-0395, Japan* yamada.akihisa.679@s.kyushu-u.ac.jp
2
Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku,
Fukuoka, 819-0395, Japan

ABSTRACT
Numerical prediction of cavitation with higher accuracy is one of the important issues for thedevelopment of more reliable high-speed hydraulic machines, and it can also bring us many
useful visualization data which are difficult to be obtained experimentally. Currently, ahomogeneous model as one of the cavitation models is often used in the field of fluid machinery
due to the low computational cost with its simplicity [1]. However, the quantitative accuracy oftypical one-equation homogeneous models only focusing expansion/shrinkage of bubbles orthe evaporation/condensation is not high.
Multi-Process (MP) model is a four- or five-equation homogeneous model developed by Tsudaet al. (2015) [2]. MP model can take account of main elementary processes in cavitation using
the moment method for a size distribution function of cavitation bubbles. It solves several
equations for moment variables corresponding to the number density of the bubbles, thedensities of the radius and the surface area, and so on. Therefore, it is expected to improve theprediction accuracy compared with typical one-equation models. In this study, unsteady RANS
(Reynolds Averaged Navier-Stokes) simulation using MP model was carried out targeting thefinal stage model of a three-stage centrifugal pump.
We have conducted the simulations at various NPSH (Net Positive Suction Head) conditions to
obtain the head breakdown curve at the design flow rate. Good agreement was obtained between
the experiment and the simulation in the trend of them. Axial thrust force was almost constantbefore the head breakdown, then decreased sharply. At lower NPSH, local velocity increase
was observed due to blockage of the flow path in the impeller by the growing cavity. In addition,
separation occurred downstream of the cavity in the impeller after the head drop. We alsovisualized each moment variable in MP model, and a size polydisperity of cavitation bubbles
as one of the characteristics in MP model was clearly confirmed, indicating that it qualitatively
works well also in terms of a useful visualization.
REFERENCES[1] Singhal, A.K. et al., "Mathematical basis and validation of the full cavitation model", J.
Fluid Eng., Vol. 124, No. 3 (2002), pp. 617-624.
[2] Tsuda, S. and Watanabe, S., 2015 Application of multi-process cavitation model forcavitating flow in cold water and in liquid nitrogen around a hydrofoil, Proc.
ASME/JSME/KSME 2015 Joint Fluids Eng. Conf. (Seoul, South Korea), (2015),
AJKFluids2015-05532.

PSFVIP13-44

COLOR PIV FOR MEASURING THREE-DIMENSIONAL WAKE STRUCTURES
OF A DELTA WING FROM 0 TO 90 DEGREE IN ANGLE OF ATTACK*K. Ochi1, Y. Horimoto1, H. J. Park1, Y. Tasaka1 and Y. Murai1
1

Hokkaido University, Nishi-8-chome, Kita-13-jo, Kita-ku, Sapporo, Hokkaido 060-8628
Japan*ochi.k@ring-me.eng.hokudai.ac.jp

ABSTRACTIn recent years, the demand for measurement of wing characteristics in the relatively low
Reynolds number range (Re = O(103–105)) has increased due to the rapid development of
unmanned aerial vehicles. Since the wing characteristics of a delta wing depend on its wakestructures, it is necessary to visualize the structures and clarify the mechanism that influences
flying stability. In order to measure the wake structure in multiple dimensions, we employ
particle image velocimetry with multiple-color-layer illumination (color PIV), which is suitablefor 3D measurements for large-scale structures in air flows. In particular, we attempt tovisualize the wake structure widely in the angle of attack (AoA) from 0 to 90 degree, wherelongitudinal vortex transits to vortex shedding via very complicated multi-polar vorticalstructures.
Using the set-up of three-layer color-coded PIV in a wind tunnel facility, we obtained velocity
vector distribution in the three layers simultaneously as a time series. Analyzing vorticity andstreamlines from the PIV data, we confirmed a pair of steady leading-edge vortex separation
behind the delta wing for AoA less than 25 degree. For AoA close to 90 degree, alternative
vortex shedding similar to von Kármán vortex was found with Strouhal number of around 0.2,
which was also validated by a hot-wire anemometer by calculating the power spectrum ofvelocity fluctuations. At an intermediate range of AoA from 30 to 60 degree, the highest
turbulent intensity in the examined region of AoA was detected due to the 3D flow separation
occurring on the delta wing surface. The wake consists of alternations of an asymmetric vortex
pair that produced central downwash intermittently. In the presentation, we will show 3D
isosurfaces of such a wake structure obtained from the 3D color PIV data combined with aspatio-temporal correlation analysis.
REFERENCES[1] Murai, Y., Yumoto, T., Park, H. J. and Tasaka, Y., “Color-coded smoke PIV for windtunnel experiments improved by eliminating optical and digital color contamination”,
Experiments in Fluids, Vol. 62, No. 11 (2021), 231.
[2] Li, J., Zhao, X. and Graham, M., “Vortex force maps for three dimensional unsteady flows
with application to a delta wing”, Journal of Fluid Mechanics, Vol. 900 (2020), A36.

PSFVIP13-45

EVALUATION OF THE INFLUENCE OF READING PIXEL IN THE DRAG
COEFFICIENT CALUCULATED FROM HIGH-SPEED VIDEO CAMERA IMAGES*T. Miyazaki1, T. Kikuchi1 and A. Muramatsu1
1

Nihon University, 7-24-1 Narashinodai, Funabashi, Chiba 274-8501, Japan*cstm21032@g.nihon-u.ac.jp

ABSTRACTIn an experiment using a ballistic range which launches a projectile, Reynolds number andMach number can be set independently by changing the pressure of the test range and the
projectile velocity. The drag coefficient can be also obtained without the model support
interference which is a problem in a wind tunnel experiment. It is used for ground-based
experiments of re-entry into the atmosphere [1] and is expected to become a promisingexperimental technique. The influence of error due to low resolution of high-speed video
camera [2] was statistically evaluated to precisely calculate the drag coefficient from the highspeed images measured in a ballistic experiment. The location history of a free-flight projectile
was calculated by a true drag coefficient arbitrary setting and photographic condition. The dragcoefficient, which was calculated from the projectile location history containing error generated
by reading error of pixel adding to this true location history, differs from the true dragcoefficient. The average of this difference which was drag coefficient error due to reading error
converged by the Monte Carlo simulation which in the reading error of normal distribution
random in ranging from –σ to +σ. The influence of reading errors on the calculation of the dragcoefficient correlated better with the visualization area and camera resolutions and did notcorrelate with the resolution per pixel. This prediction was verified by ballistic experiments, inwhich the flow fields around 6.35 mm diameter polyacetal projectiles launched by a light gas
gun were visualized by the shadowgraph method. The standard deviation of the drag coefficientfor each conditions indicated similar trends to the simulation. Producing a quantitative index
which estimates experimental error enables to set photographic condition of highest precisionand to give a statistically expected error bar for a single experiment.
REFERENCES[1] Hideki. K. et al, “Wake Flow Analysis of a Free Flight Capsule at Transonic Speeds”,
Symposium on Shock Waves in Japan, 2019[2] Tomoharu. K,“Shock Standoff Distance around a Near-Sonic” ,graduation thesis, 2017

PSFVIP13-46

EXPERIMENTAL INVESTIGATION OF SHEAR-INDUCED BIREFRINGENCE
PROPERTIES OF RHEOSCOPIC FLUIDS FOR VISUALIZATION OF STRESSFIELD OF FLUID FLOW
*K. Hayashi1, S. Tanaka1, and K. Shirai1
1

Shibaura Institute of Technology, 3-7-5 Toyosu, Koto, Tokyo 135-8548 Japan*kshirai@shibaura-it.ac.jp

ABSTRACT
Fluid shear stress is one of the fundamental parameters in fluid mechanics. Shear stress at thesurface of a solid wall is used for calculating the friction force. In Newtonian fluid, shear stressis proportional to the velocity gradient, which is closely related to the production of turbulence.
Measurement of shear stress requires either to use certain analogy or to acquire the velocity
gradient in Newtonian fluid. The former method provides surface distributions of the wall shear
stress such as liquid crystal coating, shear sensitive polymer film or micro pillar array. In case of theliquid crystal coaring, the wall shear stress is evaluated based on the colour variation of the coatedsurface, however, these methods are restricted to the surface shear stress. In the latter method,
one needs to obtain fluid velocities at two closely located independent positions. The
measurement suffers from the uncertainties of the spatial positions as well as the fluid velocities.
Hence, direct evaluation of shear stress field is expected in a fluid flow. In the present study,
we investigate the feasibility of imaging the stress field of fluid flow. The method relies on thephotoelasticity of rheoscopic fluid. In a fluid flow with rheoscopic fluid, elongated colloidal
particles align to the induced shear stress and the alignment produces birefringence. The flowinduced birefringence is correlated with shear stress of the flow. Therefore, we have a
possibility of evaluating the stress field through proper analysis of the birefringence state. The
purpose of this study is to evaluate the birefringence and extinction angle of rheoscopic fluids
at different shear conditions. To this end, the known shear stresses are applied to the fluids byusing a rotating Couette flow. We used two different working fluids known as rheoscopic fluid.
We discuss on the dependencies of the photoelastic coefficients on different shear conditions
towards quantitative imaging of fluid stress field.

PSFVIP13-47

INFLUENCE OF THE THIRD STREAM TO A THREE-FEED NON-PREMIXEDCOMBUSTION SYSTEM*S. Yadav1, P. Yu1, and H. Watanabe1
1

Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 Japan*imsujeet@tse.kyushu-u.ac.jp

ABSTRACT
Three-stream non-premixed combustion systems have been widely applied in the industry, andthe corresponding flamelet-based models have also been developed. However, besides the fuelstream and oxidizer stream, the influences of the third stream to the whole system and theflamelet-based models need further research. In this work, influences of two different third
streams, such as pure inactive diluent and oxidizer contained stream, to the chemistry are
investigated by means of two-dimensional (2D) direct numerical simulations (DNS). It is
confirmed that for a pure inactive third stream the influence of its scalar dissipation rate to thechemistry can be neglected when its mixture fraction is not very large, for instance, less than
0.8. Data obtained from large-eddy simulations (LES) with identical probability density
function for mixture fractions further supports this conclusion. As the third stream is oxidizercontained, its scalar dissipation rate and the cross-scalar dissipation rate affect the chemistry
significantly. It is observed in the flamelet library the deviation for temperature distribution
from the DNS data cannot be overlooked if the cross-scalar dissipation rate for this oxidizercontained stream and fuel stream is ignored. It is also found as the mixture fraction of theoxidizer stream increased, the influence of the cross-scalar dissipation rate between theoxidizer-contained third steam and fuel stream is diminished. It is found that with the crossscalar dissipation rate for this oxidizer-contained third stream and the oxidizer stream is ignored
there is almost no difference.

PSFVIP13-48

SPATIAL SUPERRESOLUTION BASED ON PROPER ORTHORGONALDECOMPOSITION AND BAYSIEN ESTIMATION OF SUBSONIC JET FLOW
MEASURED BY TWO MAGNIFICATION PIV SIMULTANEOUS MEASUREMENT*H. Honda1, Y. Ozawa1 and T. Nonomura1
1

Department of Aerospace Engineering, Tohoku University, Sendai, Miyagi, 980-8579, Japan*honda.harutaka.p8@dc.tohoku.ac.jp

ABSTRACTA subsonic jet generates strong acoustic waves while propelling the airplane. This
acoustic wave triggers fatigue failure to the structures and generates noise to the ambient. The
researches aiming to predict and reduce the acoustic wave have been conducted for more thanhalf a century[1]. These acoustic waves are generated by the convection and fluctuation ofvortices in turbulent flow, and its intensity increases in proportion to the eighth power of the jet
velocity[2]. Particle image velocimetry (PIV) is one of the methods for investigating the
behaviour of vortices in turbulent flows and has been applied to the subsonic jet[3, 4]. The
spatial resolution of the PIV measurement is defined by the field of view of the camera, and theaccuracy of the PIV analysis is affected by the resolution of the particles within the image.
Since the spatial resolution of locally small flow fields such as vortex structures near the shear
layer degrades in a wide field of view, it is difficult to capture the entire flow in a wide field ofview while keeping the high spatial resolution. This research aims to address the issue by
designing the spatial super-resolution framework to expand the limitation of the PIV
measurements.
The reconstruction framework based on proper orthogonal decomposition and Bayesianestimation was designed for the spatial super-resolution of a subsonic jet, and the simultaneous
two PIV measurements of a subsonic jet with different magnifications were conducted for
obtaining datasets for training and testing the framework. The designed framework wasevaluated using the artificial data generated from the average pooling from the high-resolution
training data. The reconstruction error of the proposed framework was estimated to be 71% at
the resolution ratio of 1:10 using 300 POD modes. In the simultaneous two-magnification PIV
measurement, pair images of broad and close-up views of the jet in the same plane wereobtained successfully.
REFERENCES[1] Jordan, P., and Gervais, Y., “Subsonic jet aeroacoustics: associating experiment, modellingand simulation,” Experiments in Fluids, Vol. 44, No. 1, 2008, pp. 1–21.
[2] Lighthill, M. J., “On sound generated aerodynamically I. General theory,” Proceedings of
the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 211, No.
1107, 1952, pp. 564–587.
[3] Bridges, J., and Wernet, M. P., “The NASA subsonic jet particle image velocimetry (PIV)
dataset,” 2011.
[4] Rodríguez, D., Cavalieri, A. V., Colonius, T., and Jordan, P., “A study of linear wavepacket
models for subsonic turbulent jets using local eigenmode decomposition of PIV data,”
European Journal of Mechanics-B/Fluids, Vol. 49, 2015, pp. 308–321.

PSFVIP13-49

NUMERICAL ANALYSIS OF INTERNAL FLOW IN A SEPARATEHERRINGBONE PLATE HEAT EXCHANGER*D. Fujiwara1 and S. Torii1
1

Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555 Japan
188t2228@st.kumamoto-u.ac.jp

ABSTRACTThe purpose of this study is to visualize the flow inside a heat exchanger with a separate
herringbone plate and to clarify the phenomenon of heat transfer enhancement. The analysis
software used is STRA-CCM+, a three-dimensional thermal-fluid analysis software. The
method used for discretization was the finite volume method (FVM). The AKN model (AbeKondoh-Nagano low-Re k-epsilon model) of Reynolds averaged Navier-Stokes (RANS) is
used in the analysis. Reliability of the solution is ensured by comparison with experimental
values. Separate herringbone plate is plate with the center of the turbulence promoter of theherringbone plate smoothed. Finally, the shape of the plate has been shown to have superior
heat transfer and flow performance compared to commonly used plates. In the analysis, highand low temperature fluids are flowed along the wall of a titanium plate for heat exchange. The
working fluid is water, and heat is exchanged by counter flow. The high temperature fluid flows
upward on the convex side of the plate and the low temperature fluid flows downward on the
concave side of the plate. The analysis results shows that the overall heat transfer coefficient is
consistent with the experimental values. The velocity distribution between the ribs of the hightemperature channel confirms the presence of reattachment points due to flow separation. The
temperature distribution shows a high heat transfer coefficient in the region near thereattachment point. Consequently, it can be confirmed that heat transfer enhancement took
place inside the heat exchanger due to the high heat transfer coefficient in the reattachment
point region.
REFERENCES[1] Torii, S. and Izumi, K., “Effect of Plate Shape and Size on Thermal Fluid Flow in
Channel”, JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER, Vol. 26, No. 4(2012), pp. 598-601.

PSFVIP13-50

VISUALIZATION OF TRANSIENT HEAT TRANSFER BY A DROPLETBOUNCING ON A HEATED SURFACE VIA THERMOGRAPHY*M. Yoshida1, S. Yamada2, Y. Funami2 and H. Nakamura2
1

Department of Equipment and Structural Engineering, Graduate School of Science andEngineering, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa
239-8686 Japan*ed21011@nda.ac.jp
2
Department of Mechanical Engineering, School of Systems Engineering,
National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686 Japan

ABSTRACTIn this study, we attempted to measure the transient heat transfer of the Leidenfrost phenomenon
caused by a single falling ethanol droplet colliding with a high temperature heat transfer surface.
Visualization was done with two visible cameras and an infrared (IR) camera. The droplet
behavior was photographed by two visible cameras, one from diagonally above and the otherthrough the heat transfer surface. Simultaneously, we measured the transient temperature
distribution by the IR camera. For the measurement, the calcium fluoride (CaF2) on which an
indium tin oxide (ITO) film was formed was used as the heat transfer surface. CaF2 istransparent to visible light and IR radiation. On the other hand, ITO film is transparent to visible
light and opaque to IR radiation. So, it is possible to acquire a visible image of the droplet
dynamics seen from above and below, and to measure the transient temperature distribution of
the heat transfer surface at the same time. Furthermore, by numerically solving the threedimensional transient conduction equation, the transient surface heat flux was calculated fromthe measured temperature distribution. Thus, we were able to capture the dynamics and thetransient heat transfer of the Leidenfrost phenomenon. The contact time of the droplet on theheated surface was compared with the empirical formula [1]. In addition, the heat transfer
characteristics were compared with the previous study [2].
REFERENCES[1] Richard, D., Clanet, C., Quéré, D., “Contact Time of a Bouncing Drop”, Nature, Vol. 417,
(2002), pp. 811.
[2] Jung, J., Jeong, S., Kim, H., “Investigation of Single-droplet/wall Collision Heat Transfer
Characteristics Using Infrared Thermometry”, International Journal of Heat and Mass
Transfer, Vol. 92 (2016), pp. 774–783.

PSFVIP13-51
VISUALIZATION OF TEMPERATURE FIELD IN A CHANNEL BY LASERINDUCED FLUORESCENCE AND TEMPERATURE DEPENDENCE OF PARTICLE
BEHAVIOR IN THE CHANNEL*K. Hirai, M. Yajima, H. Kato and K. Shirai
Department of Mechanical Engineering, Shibaura Institute of Technology 3-7-5 Toyosu,
Koto, Tokyo 135-0045 Japan*md21098@shibaura-it.ac.jp
ABSTRACT
It has been reported that mixing fine particles into the solution improves the thermal
conductivity over that of the original solution.[1] The operational potential of nanoparticles as
high-energy carriers has also been shown.[2] From the above, it is important to observe theparticle movement near the boundary surface of different phases where heat exchange is active,
considering the effects of Brownian motion and thermophoresis. Although the colloidal particle
velocity have been measured near the solid-liquid boundary using Evanescent Wave Particle
Tracking Velocimetry (EWPTV)[3], no measurements have been made under different
temperature conditions. In this study, we measured the temperature field in a microchannel
using thermocouples and Laser Induced Fluorescence (LIF) and the colloidal particle velocity
in a microchannel near the solid-liquid boundary using EWPTV. The experimental device usedin this study was shown to be capable of forming a stable temperature field in the channel. The
particle velocity in the channel was found to follow the Hagen-Poiseuille flow as an
approximation, but it was found that an apparent slip velocity occurs as it approaches thevicinity of the wall surface. The particle velocity and fluorescence intensity values near the wallwithin the EW penetration depth range, which is shorter than a hundred micro meter, were
proportional to the distance from the wall, yielding linearity. In addition, the particle
fluorescence brightness values were found to be inversely proportional to the wall distance.
From the above results, we expect that the particle velocities aren’t only measured near the wallusing EWPTV under various temperature conditions, but also the exponential decay of the EW
light intensity was used to feasibly locate particles in three dimensions with a single camera.
REFERENCES[1] Choi, S.U.S., Eastman, J.A., “Enhanced Heat Transfer using Nanofluids”, Patent, UnitedStates (2001).
[2] Yang, C., Li, W., Sano, Y., Mochizuki, M. Nakayama, A., “On the Anomalous Convective
Heat Transfer Enhancement in Nanofluids: A Theoretical Answer to the Nanofluids
Controversy”. Journal of Heat Transfer Vol.135 (2013), 054504.
[3] Kato, H., Hirai, K., Maruyama, K., Shirai, K., “Experimental observation of near-wallmotions of colloidal particles based on particle tracking using with evanescent lightillumination”, The 32nd International Symposium on Transport Phenomena (2022).

PSFVIP13-52
VISUALIZATION-BASED MEASUREMENT OF FLOW VELOCITY IN A MOLDED PIPE
WITH MATCHED REFRACTIVE INDEXS. ISHII1, S. FUKUSHIMA1 and K. SHIRAI1
1

Department of Mechanical Engineering, Shibaura Institute of Technology
3-7-5 Toyosu, Koto, Tokyo 135-8548 Japan

ABSTRACTIn human body, oxygen and … are transported through thousands of blood or lymph vessels. The
flows can be simulated with round shaped pipe flows with small diameters. However, flow velocity in around pipe is difficult to be measured due to its curvature. Even when the pipe is made of a transparent
material, difference of the working fluid, pipe material, and the surrounding environment causes
refractions and reflections at their boundaries. These effects lead to image distortions and strong
scattering at the boundaries. In the present study, we match the refractive indices of the working fluid,
pipe material and the surrounding. We creased the flow tube with silicone elastomer in the laboratory.
An advantage of the self-made tube is the flexibility of creating a tube with any internal and external
diameters, which is sometimes necessary to meet the required conditions of the experiment. As theworking fluid, we used a binary mixture of water and glycerin to match the refractive index of theelastomer. The test section was immersed in a square-shaped box filled with the same liquid as theworking fluid. With the refractive-index matching, we use visualization-based method for measuring theflow velocities in the tube. The test section was illuminated with a thin laser sheet. From the images ofthe seeded tracer particles velocities are obtained by simple particle tracking. The average velocities inthe tube is measured and compared to the theoretically estimated ones. So far, the agreement of themeasurement and the theoretical ones are within 2 percent. The cause is thought to originate from thefact that refractive index matching reduces distortion due to scattered light, thereby reducing
measurement uncertainty. This will be confirmed by an independent measurement using a laser Doppler
velocimetry.
Keywords: flow visualization, velocity measurement, pipe flow, flexible tube, silicone, curvature, spatial
average, refractive index matching, particle tracking, particle image velocimetry

PSFVIP13-53
DIFFERENCES IN FLOW AROUND GOLF BALLS WITH DIFFERENT DIMPLE
OCCUPANCY, VOLUME RATIO AND DEPTH*K. Moriyama1, H. Okanaga1
1Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa, 259-1292, Japan*1cemm098@mail.u-tokai.ac.jp

ABSTRACTThe surface of a golf ball has many dents called dimples to improve the flight distance. The
dimple occupancy and dimple volume ratio to the golf ball is very important in particular to
the aerodynamics characteristics. Therefore, we made 15 model balls with different occupancy
and volume ratio. The occupancy was varied using the diameter and number of dimples. In
addition, the dimple depth was changed to the volume ratio. We conducted lift and dragmeasurement experiments by wind tunnel experiments. Then, a flight trajectory simulation was
performed using the obtained lift and drag data, and it was clarified how the occupancy and thedimple volume ratio affect the flight distance. The most flying model ball had a high occupancyof 83.1% and a dimple volume ratio of 11.3×10-3. This model ball is characterized by a larger
dimple diameter and a shallower dimple depth than other spheres. We will visualize the flowof each of the spheres using the wind tunnel experiments by the spark tracking method. Then,
we clarify the relationship between the aerodynamic characteristics and to the difference in theoccupancy and the dimple volume ratio from flow visualization.
REFERENCES[1] K. Aoki, M. Nonaka, T. Goto: Effect of dimple structure on the flying characteristics andflow patterns of a golf ball, The Engineering of Sports 5, Vol.1, pp.49-55, 2004.
[2] 2. Bin Lyu, Jeff Kensrud, Lloyd Smith, Taylor Tosaya: Aerodynamics of Golf Balls in
Still Air †, The 12th Conference of the International Sports Engineering Association,
Proceedings 2018, 2, 238[3] 3. A.J. Smits & D.R. Smith: A new aerodynamic model of a golf ball in flight, Scienceand Golf II, E.&F.N. Spon, London (1994), pp. 340-347.

PSFVIP13-54

A TIME-RESOLVED THREE-DIMENSIONAL DENSITY MEASUREMENT FOR
AN ASYMMETRICAL UNSTEADY SUPERSONIC IMPINGING JET USING AFIBRE BOS TECHNIQUE*T. Kuroda1, M. Kobayashi 1 and T. Ukai1
1Osaka Institute of Technology, 5-16-1 Omiya, Asahi, Osaka 535-8585, Japan*kuroda3939@gmail.com
ABSTRACTA supersonic jet with long shock cells impinges on the planetary surface at a high altitude for along time [1], which results in the diffusion of sands. The diffused sand causes damage to the
exploration rover's equipment. To reduce such kind of risk, a jet-jet interaction technique, which
can shorten the length of shock cells, would be useful. Kobayashi et.al. investigated the effectof jet-jet interaction on supersonic impinging jets, and the surface flow of a plate was visualized
by an oil flow visualization technique [2]. They showed that an asymmetric surface flow wasobserved in the jet-jet interaction case, and a curved flow pattern, which is a linearly symmetricpattern, appeared. From several previous studies [3, 4], we deduce that the asymmetric flow
pattern on the plate is caused by an asymmetric vortex, but further investigations are necessary
to fully understand vortex motion on the plate. In this study, we used a Fibre BOS techniquethat temporal variation of a quantitative three-dimensional density field can be measured using
a single camera [5], to visualize the Mach 2 supersonic jet with jet-jet interaction impinging aplate vertically. A Fibre BOS technique can obtain the same number of projections as thenumber of image fibre used, and nine projections were captured in this experiment. The flow
visualization captured the structure of the asymmetrical unsteady flow in the supersonic
impinging jet with jet-jet interaction. In other words, jet-jet interaction causes the unsteady flow
field on the plate. Additionally, jet-jet interaction reduced the density change on the plate.
Prospects are to reconsider the experiment after confirming the reproducibility of the image
reconstruction of the Fibre BOS technique.
REFERENCES[1] Mehta, M., Renno, N.O., Marshall, J., Grover, M.R., Sengupta, A., Rusche, N.A., Kok,
J.F., Arvidson, R.E., Markiewicz, W.J., Lemmon, M.T. and Smith, P.H., “Explosive
erosion during the Phoenix landing exposes subsurface water on Mars,” Icarus, Vol. 211,
No.1 (2011), pp. 172, 194.
[2] Kobayashi, M. and Ukai, T., “Surface and spatial flow structure of an underexpanded jetwith vertical jet interactions impinging on perpendicular and inclined plates”, AIAA Paper
2022-2582 (2022).
[3] Geers, L.F.G., Hanjalic, K. and Tummers, M. J. “Wall imprint of turbulent structures andheat transfer in multiple impinging jet arrays,” Journal of Fluid Mechanics Vol. 546 (2005).
[4] Thielen, L., Jonker, H.J.J. and Hanjali, K., “Symmetry breaking of flow and heat transfer
in multiple impinging jets,” International Journal of Heat and Fluid Flow, Vol. 24, No. 4(2003), pp. 444-453.
[5] Ukai, T., “The principle and characteristics of an image fibre Background Oriented
Schlieren (Fibre BOS) technique for time-resolved three-dimentional unsteady density
measurements”, Experiments in Fluids, Vol. 62 (2021).

PSFVIP13-55

PRELIMINARY STUDY OF MICROJETS FROM RECTANTULAR CONVEREGNTNOZZLES WITH HIGH-ASPECT RATIOS*S. Yoshimi1, S. Nakao1, and Y. Miyazato 1
1

The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, 808-0135 Japan* acadress443@gmail.com

ABSTRACTMicrojets issued from rectangular nozzles with high aspect ratios (AR: the ratio of the major
dimension to the minor dimension at the nozzle exit) have been widely used for gas wiping incontinuous galvanizing line. However, little is known about the flow characteristics of suchmicrojets because of challenging issues. Handa et al. [1] applied the molecular tagging
velocimetry (MTV) for supersonic microjets issued from a convergent-divergent nozzle with adesign Mach number of 2.0 and a rectangular shape of 500 m × 5000 m (AR = 10) at thenozzle exit. They clarified effects of Reynolds number on the microjet structure including thesupersonic core length and the velocity decay process. Aniskin et al. [2] investigated effects of
the Pitot microtube diameter on the main parameters of plane underexpanded microjets such as
the shock-cell spacing and the supersonic core length. Two convergent nozzles with sizes of
22.3 m × 2593 m (AR = 116) and 83.3 m × 3823 m (AR = 46) at the nozzle exit and two
glass Pitot tubes with inner diameter (m) /outer diameter (m) of 24/70 and 16/42 were usedin the experiments. As a result, they found that the length of the first shock-cell measured by
the Pitot microtube is overestimated in comparison with that visualized by the shadowgraphmethod, but the Pitot tube diameter has a minor effect on the supersonic core length.
In the present study, the flow structure of a shock-containing microjet issued from arectangular convergent nozzle with a high-aspect ratio is investigated experimentally by therainbow schlieren deflectometry. A convergent nozzle with a rectangular shape of 300 m ×3000 m (AR = 10) at the nozzle exit is used in the experiments and the nozzle pressure ratio(NPR: the ratio of the plenum pressure upstream of the nozzle to the back pressure) is held
constant at 4.0 to produce a Mach stem in the first shock-cell of the jet plume. In addition, theflow field of rectangular microjets is simulated by solving the Reynolds-averaged NavierStokes (RANS) equations to investigate the near-field shock structure of the jets. The Menterk- shear-stress transport (SST) model is used for the simulations because it has been widelyused and trusted model in areas of aerospace community. Three-dimensional flow structure ofshock-containing jets issued from a rectangular convergent nozzle with a high aspect ratio isdisplayed by computer flow visualizations.
REFERENCES[1] Handa, T., Mii, K., Sakurai, T., Imamura, K., Mizuta, S. and Ando, Y., “ Study ofSupersonic Rectangular Microjets Using Molecular Tagging Velocimetry”, Experiments
in Fluids, (2014), 55: 1725.
[2] Aniskin, V. M., Timofeev, I. V., Maslov, N. A., and Tsibulskaya, E. O., “Effect of the Pitot
Microtube Diameter on Pressure Measurement in Plane Supersonic Microjets”, Flow
Measurement and Instrumentation, Vol. 70 (2019), 101655.

PSFVIP13-56
IMPROVEMENT OF PARTICLE TRACKING VELOCIMETRY
WITH DEEP LEARNING*T. Yano1 and Y. Nakanishi1
1

Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama, Kanagawa
221-8686 Japan*t-yano@kanagawa-ua.c.jp

ABSTRACT
Understanding of the velocity distribution in a fluid flow is important in the field of fluid
engineering, and the measurement techniques of flow velocity have been studied for a long time.
The flow measurement with video camera and fine tracer particles, which measures the flow
velocity based on the traceability of particles to the fluid motion, is an effective technique. This
technique can obtain multipoint velocities simultaneously, and it can be classified into particle
tracking velocimetry (PTV) and particle image velocimetry (PIV) depending on the method forderiving the velocity. When the number density of tracer particles is the same, the spatial
resolution of PTV is supposed to be higher than that of PIV because the former determines thevelocity from the motion of individual particles and the latter determines from the correlationof the pattern of particle distribution. However, there is a problem in PTV that the measurement
accuracy deteriorates with increase in the number density of tracer particles. This problem has
been challenged by several researchers (e.g., Schanz et al. [1] developed the technique known
as “Shake-The-Box”). The purpose of this study is to improve the accuracy of PTV for densely
seeded particle images by using the deep learning.
The main procedures of PTV are as follows: (1) detect tracer particles on the image, (2) track
motions of tracer particles during short time intervals, and (3) convert results from image
coordinates to absolute coordinates. Currently, the deep learning is applied to procedure (1).
Firstly, as many candidates of tracer particles on the image are obtained by Hough transform
method, which is an analysis technique for extracting circles on the image. After that, thecorrectness/incorrectness of the obtained candidates is classified by the supervised deeplearning with convolution neural network (CNN) [2]. The accuracy of particle detection can be
improved by eliminating the candidates judged to be incorrect. As a result of the verification
using synthetic particle images, the detection of tracer particles on dense particle images wererealized with good accuracy (e.g., approximately 98% and 86% of particles were correctly
detected for images with 0.01 and 0.05 particles per pixel (ppp), respectively), and theeffectiveness of the present method was demonstrated.
REFERENCES[1] Schanz, D., Gesemann, S. and Schröder, A., “Shake-The-Box: Lagrangian Particle
Tracking at High Particle Image Densities”, Experiments in Fluids, Vol. 57, No. 5 (2016),
70.
[2] LeCun, Y., Bottou, L., Bengio, Y. and Haffner, P., “Gradient-Based Learning Applied toDocument Recognition”, Proceedings of the IEEE, Vol. 86, No. 11 (1998), pp. 2278–2324.

PSFVIP13-57

EXPERIMENTS ON FLOW FIELD CONTROL USING A UNIDIRECTIONAL
ACOUSTIC FLOW GENERATOR DEVICE* H. Kawashima1, S. Miyazaki1 and T. Hiroi11National Maritime Research Institute, 6-38-1 Shinkawa, Mitaka Tokyo 181-0004 Japan*kawasima@m.mpat.go.jp

ABSTRACT
A flow field control device using an acoustic streaming is being developed to control the
turbulent flow field in a turbulent boundary layer from the wall surface area. By inputting highfrequency power to a transducer installed on a piezoelectric substrate, surface acoustic waves(SAW) can be radiated on the piezoelectric substrate to generate acoustic streaming in a liquidadjacent to the substrate. A commonly used method of generating acoustic streaming has been
to use a SAW device composed of a bidirectional interdigitated electrodes (IDT) on a
piezoelectric material base of single crystal lithium niobate (LiNbO3) [1][2][3]. This method
was not suitable as a flow field control device because the acoustic streaming was generated at
an angle of 67.5 degrees to the wall surface due to the sound speed of the piezoelectric substrate
being too fast compared to the sound speed of water, and the vertical component of the acoustic
stream to the wall surface was larger than the horizontal component. Also, because the IDT isbidirectional, the acoustic streaming is generated in a V-shape, and the horizontal componentof the flow velocity is the same back and forth, which was another reason why it was not suitable
as a flow field control device.
The flow field control device employs BGO (Bi12GeO20) [4], a piezoelectric substrate withsurface wave sound velocity closer to sound velocity of water, to reduce the angle of thegenerated acoustic streaming to the wall surface to about 30 degrees. By applying aunidirectional circuit [5] for generating surface waves, the acoustic streaming can be generated
in almost one direction. Acoustic streaming tests were conducted using the flow field control
device in a water tank. The acoustic streaming was then generated using the developed flow
field control device and measured by PIV. The angle of acoustic streaming was 29.9 degrees tothe wall surface, and the maximum velocity was 31.6 mm/s when power was applied at a
voltage of 40 V. Input voltage and maximum flow velocity were generally proportional.
REFERENCES[1] Shiokawa, S., Matsui, Y., Ueda T., “Study on SAW Streaming and its Application to Fluid
Devices”. Proceedings of 10th Symposium on Ultrasonic Electronics 1989, Japanese
Journal of Applied Physics, Vol. 29 (1990), pp.137-139.
[2] Maezawa, M., Kamakura, T., “Sound Field Evaluation and Flow Visualization in Water
by SAW device”. IEICE technical report, (2007), pp.47-51.
[3] Kong, D., Kurosawa, M. K., “A Novel Approach to Swimmer Actuation via Surface
Acoustic Wave”. Proceedings of Symposium on Ultrasonic Electronics, Vol. 39 (2018)[4] Cambell, C., “Surface Acoustic Wave Devices and Their Signal Processing Applications”.
Academic Press, (1989), pp.20[5] Kondo, J., “Development of Liquid-Phase Sensing System Using Acoustic Wave Devices”.
Technical Report of Industrial Technology Research Grant Program in FY2006, (2007)

PSFVIP13-58

PRELIMINARY STUDY OF UNDEREXPANDED SONIC JETS FROM ELLIPTICCONVERGENT NOZZLES*T. Nagata1, M. M. Islam1,2, T. Miyaguni, S. Nakao1, and Y. Miyazato1
1

The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, 808-0135 Japan* ntatsuya2000@outlook.com
ABSTRACT

It has been recognized that elliptic nozzles provide improvements in flow mixing within the
supersonic jets when compared with the axisymmetric nozzles. Menon and Skews [1]experimentally investigated the gross features of shock-containing elliptic jets by the
shadowgraph technique and simulated the near-field shock structure by solving the Reynoldsaveraged Navier-Stokes (RANS) equations. Most recently, Rao et al. [2] applied the proper
orthogonal decomposition (POD) and dynamic mode decomposition (DMD) to the timeresolved schlieren data of under-expanded supersonic jets issuing from a high aspect ratio
elliptic nozzle and extracted the coherent information associated with the screeching behaviour
and closure mechanism of a feedback loop for the flapping mode. However, the flow
characteristics of the near-field shocks of elliptic underexpanded jets are still elusive. In thepresent study, shock-containing elliptic jets are investigated experimentally by the rainbow
schlieren deflectometry where a rainbow filter with fine colour gradations is placed
perpendicular to the nozzle axis in the schlieren cut off plane in such a manner that thestreamwise density gradient can be captured. An elliptic convergent nozzle with an aspect ratioof AR = 2 at the exit (AR is defined as the ratio of the major dimension to the minor dimension
at the nozzle exit) is used in the present study. The semi-major and semi-minor dimensions at
the nozzle exit are 5 mm and 2.5 mm, respectively. The nozzle pressure ratio (NPR = pos / pb)of the plenum pressure pos upstream of the nozzle to the back pressure pb is held constant at
NPR = 3.0 to produce a slightly underexpanded sonic jet. Rainbow schlieren pictures of theelliptic jets are taken independently from the jet major and minor axis directions by rotating thenozzle about its central axis. The flow structures of the elliptic jets at the jet major and minor
axis plane views are demonstrated with fine colour gradations that correspond to the density
gradient in the streamwise direction. The shock-cell spacing of the first shock-cell of the elliptic
jet plume is obtained from the hue distribution along the jet centreline and it is compared
quantitatively with that estimated by the vortex sheet model [3] for elliptic underexpanded jets.
REFERENCES[1] Menon, N. and Skews, B. W., “Shock Wave Configurations and Flow Structures in NonAxisymmetric Underexpanded Sonic Jets, Shock Waves, Vol. 20, No. 3 (2010), pp.175170.
[2] Rao, A. N., Kushari, A. and Mandal, A. C., “Screech Characteristics of Under-ExpandedHigh Aspect Ratio Elliptic Jet”, Physics of Fluids, Vol. 32, No. 7 (2020), 076106.
[3] Tam, C. K. W., “The Shock-Cell Structures and Screech Tone Frequencies of Rectangular
and Non-Axisymmetric Supersonic Jets, J. Sound and Vibration, Vol. 121, No. 1 (1988),
pp. 135-147.

PSFVIP13-59

OSCILLATORY CHARACTERISTICS OF SHOCK TRAINS IN SQUARE DUCTS*T. Inadomi1, R. Fukunaga1, T. Takeshita1, S. Nakao1, and Y. Miyazato1
1

The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, 808-0135 Japan* takatoac@outlook.jp

ABSTRACT
Shock trains appear in a variety of flow devices such as supersonic wind tunnels, supersonicejectors, and isolators of scramjet engines [1]. It is well known that shock trains oscillate andinduce strong pressure fluctuations, leading to vibration of the fluid machines or significant
noise. Recently, understanding of the behaviour of an unsteady shock train is of great need in
the context of the design of scramjet engines [2] since a higher engine thrust can be achieved
when a shock train is confined inside the isolator of the scramjet engine. Furthermore, shock
train oscillations have a significant effect on the unstart problem. Takeshita et al. [3] applied thehigh-speed Mach-Zehnder interferometry for an isolator shock train and performed the fringeshift analysis for the unsteady interferograms of the shock train to acquire the oscillatory
characteristics of the first, second and third shocks in the shock-train.
In the present study, the oscillatory characteristics of a shock train in a square duct isinvestigated by the high-speed Mach Zehnder interferometry with the finite-fringe setting
where a He-Ne laser with a wavelength of 632 nm is used as a light source. A Laval nozzle witha design Mach number of 1.5 and a square shape of 10 mm × 10 mm at the exit is used in thepresent experiments and it is followed by a square duct with a streamwise length of 50 mm.
Interferograms of the shock train are recorded in 1,000 pictures with 21,600 frames per second
by a high-speed digital camera (Photron, FASTCAM SA1.1). The effective spatial resolution of
the present imaging system is 24 pixel/mm or 41 m/pixel.
The time-resolved density fields of the shock train are reconstructed by the fringe-shift
analysis of the interferograms of the shock train and the density calculation from the fringe
shift. The two-dimensional fluctuating density field including the shock train, the following
mixing region, and the boundary layer flows within the interaction region are demonstrated
quantitatively.
REFERENCES[1] Matsuo, K., Miyazato, Y. and Kim, H. D., “Shock Train and Pseudo-Shock Phenomena inInternal Gas Flows”, Progress in Aerospace Sciences, Vol. 35, No. 1 (1999), pp. 33-100.
[2] Gnani, F., Zare-Behtash, H. and Kontis, K.,”Pseudo-Shock Waves and Their Interactionsin High-Speed Intakes, Progress in Aerospace Sciences, Vol. 82 (2016), pp. 36-56.
[3] Takeshita, T., Nakao, S., and Miyazato, Y., “Application of Mach-Zehnder Interferometers
for Isolator Shock Trains”, ACC J., Vol. 25, No. 1 (2019), pp. 68-77.

PSFVIP13-60

VISUALIZATION OF BUBBLE DYNAMICS INSIDE THE PROOFING BREAD
DOUGH USING X-RAY MICROTOMOGRAPHY*K.Kimura1, K.Kikuchi1, K.Numayama2, T.Ishikawa2 and T.Miyagawa3
1
Department of Finemechanics, Graduate School of Engineering, Tohoku University
6-6-01 Aramaki Aza Aoba, Sendai, Miyagi 980-8579 Japan
2
Graduate School of Biomedical Engineering, Tohoku University
6-6-01 Aramaki Aza Aoba, Sendai, Miyagi 980-8579 Japan
3
Graduate School of Science and Technology, Hirosaki University
3, Bunkyo-cho, Hirosaki, Aomori 036-8561 Japan
ABSTRACT
Bread has a bubble structure that is thought to affect its mechanical properties and texture. The
bubble structure is formed when yeast ferments and releases carbon dioxide gas. In the previous
research, it was reported that the relative density, bubble diameter, and open cell ratio affectmechanical properties such as Young’s modulus and yield stress in baked bread [1]. The purposeof this study is to clarify the relationship between the three-dimensional bubble structure andmechanical properties in bread dough during fermenting and proofing.
We made a dough sample of 3 grams following the previous research [2] (strong flour, water,
salt and yeast were added as the main ingredients and the stirring time was 60 rpm for 10
minutes.) and packed it to the bottom of a polystyrene tube bottle. We used X-ray
microtomography to visualize the internal structure of opaque bread dough. We used
MorpholibJ, a plugin for Fiji to detect the volume and number of bubbles from image data. In
the preliminary survey, by using this analysis method, we succeeded in detecting more than
65% of bead particles with a uniform size of about 0.5 mm to 0.71 mm in diameter.
As a result, we succeeded in detecting bubbles from the X-ray tomographic image data andobtaining the number and volume of bubbles. Comparing the data at 10 minutes and 60 minutes
after the start of fermentation, both the number and volume of bubbles increased. In conclusion,
we succeeded to evaluate non-destructively the growth of bubbles in the bread dough due toyeast fermentation.
REFFERENCES[1] M. C. Zghal, M. G. Scanlon, H. D. Sapirstein, “Cellular Structure of Bread Crumb and its
Influence on Mechanical Properties”, Journal of Cereal Science, 36, (2002), 167-176[2] S. Chevallier, R. Zúñiga, A. Le-Bail, “Assessment of Bread Dough Expansion during
Fermentation”, Food Bioprocess Technol, 5, (2012), 609-617

PSFVIP13-61

Improvement of Robustness on Real-time Flow Field Measurement using
Sparse Processing PIV*Chihaya Abe1, Naoki Kanda1, Sayumi Kaneko1, Kumi Nakai1 and Taku Nonomura1
1

Tohoku University, 6-6-1 Aramaki, Sendai, Miyagi, 980-8579, Japan*chihaya.abe.p1@dc.tohoku.ac.jp
ABSTRACT

Robustness of sparse processing particle image velocimetry (SPPIV) was improved, and theflow velocity field was measured in real time by improved SPPIV, where SPPIV is a method
to estimate the entire flow field from limited results of sparsely located PIV-analysis
interrogation window but was suffered from being high resolution because of outliers appearing
in the PIV analysis. In this study, high-resolution velocity field estimation was conducted byshrinking the interrogation window from 32×32 pixel to 16×16 and 8×8 pixel, and therobustness of the improved SPPIV was investigated. In the improved SPPIV, recursive localcorrelation PIV and robust principle component analysis (RPCA) based on gappy proper
orthogonal decomposition (gappy-POD) are applied to reduce the noise and improve the spatial
resolution of training data. Robust Kalman filter was applied for state estimation of real-timemeasurements, which involves an optimization problem that is iteratively calculated by fast
iterative shrinkage-thresholding algorithm (FISTA). In the wind tunnel test, the PIV
measurement and real-time measurement using improved SPPIV were conducted for the flow
velocity field around the NACA0015 airfoil model. The results of this test show that the highresolution flow velocity field can be estimated by the improved SPPIV. It was found that robust
Kalman filter is effective to reduce the estimation error significantly when the interrogation
window is small. It is because the more the number of observation points increases, the moreestimated vectors are affected by noise in difficult measurement conditions using smallinterrogation window. On the other hand, the hyperparameter in the optimization problem ishighly relevant to the results. Hence, parameter settings are important. In terms of calculation
time of SPPIV, it was found that the processing time of FISTA in robust Kalman filter is a small
percentage of the total. Therefore, improved SPPIV proposed in this study is sufficiently
feasible for real-time flow field measurement.

REFERENCES[1] Kanda, N., Nakai, K., Saito, Y., Nonomura, T. and Asai, K., “Feasibility study on realtime observation of flow velocity field using sparse processing particle image velocimetry”,
Transactions of the Japan Society for Aeronautical and Space Sciences, Vol. 64, No. 4(2021), pp. 242-245.
[2] Mattingley, J. and Boyd, S., “Real-time convex optimization in signal processing –Recent
advances that make it easier to design and implement algorithms”, IEEE Signal Processing
Magazine (2010)

PSFVIP13-62

DEPENDENCE OF MEASUREMENT ACCURACY AND TIME DELAY OF
LIFETIME-BASED DUAL-LAYER PSP/TSP ON FILM THICKNESS*H. Mori1, T. Kuroki1 and H. Nishiyama1
1

Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 Japan*hide-m@mech.kyushu-u.ac.jp

ABSTRACT
Dual-layer PSP/TSP (DL-PTSP)[1] technique is a method to compensate for the temperaturesensitivity of pressure-sensitive paint (PSP) by composite measurement of pressure andtemperature, which is based on the combination of PSP and temperature-sensitive paint (TSP)
technique.
Applying lifetime-based calibration to DL-PTSP enables simultaneous
measurement of pressure and temperature by DL-PTSP with a single-camera equipment, if the
lifetime of PSP luminophore is very different from that of TSP luminophore[2]. However,nonzero thickness of intermediate paint layers of DL-PTSP, separating the upper PSP layer andthe lower TSP layer physically, may cause temperature difference between the PSP layer andthe TSP layer, and the delay of time response of temperature measurement by the TSP layer.
Because the intermediate layers of DL-PTSP have the role to avoid photophysical interaction
between PSP luminophore and TSP luminophore, such as quenching of luminescence, theintermediate layers are indispensable for DL-PTSP, although it is desirable to decrease their
thickness. It means that there is “optimum” thickness of the intermediate layers of DL-PTSP.
In this study, the relation between the thickness of the intermediate layers and the properties of
DL-PTSP with the lifetime-based calibration method, such as the sensitivity of pressure andtemperature and the time response of temperature measurement, are examined. It is clarified
that the independence of pressure measurement and temperature measurement are kept for DLPTSP by using the lifetime-based calibration method, when the total thickness of theintermediate layers is as thin as 12µm. The time delay of the temperature measured by the TSP
layer from that of the PSP layer is as small as milliseconds if the thickness of the intermediate
layers is 12µm.
REFERENCES[1] Moon, K.J., Mori, H., Ambe, Y. and Kawabata, H., “Development of Dual-layer PSP/TSP
System for Pressure and Temperature Measurements in Low-speed Flow Field”, Proc. of
ASME-JSME-KSME Joint Fluids Engineering Conference 2011, AJK2011-11020 (2011).
[2] Moon, K.J., Mori, H. and Furukawa, M., “Simultaneous measurement method of pressure
and temperature using dual-layer PSP/TSP with lifetime-based method”, Meas. Sci.
Technol., 29-12, DOI: 10.1088/1361-6501/aae408 (2018).

PSFVIP13-63
IMAGE PROCESSING OF FLOW VISUALISATION PICTURES TO DETERMINETHE STRUCTURE OF TRANSITIONAL CHANNEL FLOW OF AQUEOUS
POLYMER SOLUTIONS* T. Okuda1, X. Song1, S. Yimprasert1, P. H. Alfredsson2 and M. Matsubara1
1

Shinshu University, 4-17-1 Wakasato, Nagano, Nagano 380-8553 Japan
21w4016j@shinshu-u.ac.jp
2
KTH Royal Institute of Technology, Stockholm, SE-100 44 Sweden

ABSTRACT
It is well known that the addition of polymer to a wall-bounded turbulent flow reduces drag,which is hypothesized to be due to the suppression of the turbulent eddy motion by thedashpot-like behaviour of the polymer [1]. The effect of polymer addition to transitional
channel flow was investigated by flow visualization [2], and it was confirmed that thetransition is delayed by polymer addition. In the present study, we quantify the effect ofpolymer addition by using image processing to obtain the intermittency ratio, which is thefraction of turbulence in the flow, as well as the scales of turbulence and streaky structures.
The experimental apparatus is a channel consisting of two flat glass walls. The total length is7320 mm and the height 7 mm. After an initial length where a trip wire is attached to one of
the walls, the channel width decreases thereby increasing the Reynolds number and the flow
becomes turbulent. The fully turbulent flow then enters a section where the width increases
which makes the Reynolds number decrease until it flows into the constant-width channel test
section where it becomes intermittent with mixed laminar and turbulent regions.
Polyacrylamide was used as the polymer. The flow was visualized by suspending reflective
pearl flakes into the water/polymer mixture and illuminating the flow downstream the exit of
the enlarged section with LED lights. The visualized flow is captured with a high-resolution
digital camera. Two moving averages of the visualized images were taken, and the local
standard deviation of the difference of the two moving averages was used to distinguishturbulent from laminar flow and to determine the intermittency ratio. Furthermore, by taking
autocorrelations of the laminar and turbulent parts cut out from the images, the streamwise
and spanwise scales of flow structures were estimated from the correlation values.
The results show that the transition to turbulent flow is delayed with polymer addition. It wasalso found that the length of the streak structures appearing around the turbulent patches
increases with increasing polymer concentration. These results indicate that polymer addition
does not only delay transition, but also significantly affects the turbulent structure in thetransitional flow.
REFERENCES[1] Den Toonder, J., Hulsen, M., Kuiken, G., and Nieuwstadt, F., “Drag reduction bypolymer additives in a turbulent pipe flow: Numerical and laboratory experiments”,
Journal of Fluid Mechanics, Vol. 337 (1997), pp. 193-231.
[2] Yimprasert, S., Alfredsson, P. H. and Matsubara, M., “Effects of polymer addition ontransition and length scales of flow structures in transitional channel flow”, 7thInternational Conference on Jets, Wakes and Separated Flows, (2022).

PSFVIP13-64

THREE-DIMENTIONAL DENSYTY MEASUREMENTUSING SIMULTANEOUS MULTI-ANGLE BOS MEASUREMENT SYSTEM
IN A SUPERSONIC WIND TUNNEL*Masato Yamagishi1, Yusuke Hirose2, Shinsuke Udagawa3, Tatsuro Inage4
and Masanori Ota1
1
Chiba University, 1-33 Yayoi Inage Chiba, 263-8522, Japan*masa0326yama@chiba-u.jp
2Tokyo Salesian College of Technology,
4-6-8 Oyamagaoka, Machida City, Tokyo, 194-0215, Japan
3
Tokyo Metropolitan College of Industrial Technology, Arakawa, Tokyo, 1168523, Japan
4
Shonan Institute of Technology, Fujisawa, Kanagawa, 2518511, Japan

ABSTRACTThe 3D-BOS technique is the three-dimensional density field visualization method for
fluid. In the past studies, the flow field around jets has been measured [1], and we succeeded inmeasuring the density around the projectile in the ballistic range for the first time [2]. On theother hand, the accuracy verification of the 3D-BOS technique is performed by comparing itwith the CFD result or conventional schlieren method, and there is no example of simultaneous
measurement of force and pressure in a supersonic wind tunnel. The 3D-BOS measurement in
the supersonic wind tunnel requires repeated experiments and the wind tunnel disturbance issignificant. Therefore, the measurement procedure is complex.
In this study, the 3D-BOS technique using the simultaneous multi-angle BOS
measurement system for density measurement is applied in a supersonic wind tunnel. With theproposed method, the number of projections can be increased for the same number of repetitions,and more accurate 3D reconstruction results are expected.
The experiment is conducted in a supersonic wind tunnel at JAXA / ISAS, and the flow
around the Cone Model installed in a uniform flow with a Mach number of 2.0 is measured. In
the conventional method, measurement with a single camera is mainly used. In contrast, theproposed method enables the measurement of the multi-angle projection data at once by thesimultaneous multi-angle BOS measurement system using 12 digital cameras. In the projection
data measured by the BOS method, the wind tunnel disturbance is observed in the entire image,and the result of the conventional method shows that the shock wave shape was distorted. On
the other hand, the proposed method succeeds in suppressing the distortion of the shock wave
shape due to the influence of the disturbance.
REFERENCES[1] F. Nicolas, D. Donjat, F. Micheli, G. L. Besnerais, A. Plyer, P. Cornic,F. Champagnat,
Y. Michou “EXPERIMENTAL STUDY OF A COUNTER-FLOW JET IN ONERA’SS1MAWIND TUNNEL BY 3D BACKGROUND ORIENTED SCHLIEREN” 18th
International Symposium on Flow Visualization Zurich, Switzerland (June 26-29, 2018)[2] Y. Hirose, K. Ishikawa, Y. Ishimoto, T. Nagashima, M. Ota, S. Udagawa, T. Inage,
K. Fujita, H. Kiritani, K. Fujita, K. Ohtani, H. Nagai “The Quantitative Density
Measurement of Unsteady Flow around the Projectile” Journal of Flow Control,
Measurement & Visualization, Vol. 7 No.2, (2019)

PSFVIP13-65

HIGH ACCURATE DENSITY MEASUREMENT OF TRANSONIC FLOW FIELDAROUND THE REENTRY CAPSULE MODEL*Yutaro Katagiri1, Nao Kosaka1, Masato Yamagishi1, Yusuke Hirose2, Masanori Ota1
Masayuki Nonura3, Koji Hujita3, Kiyonobu Kiyota3 and Hiroki Nagai3
1
Chiba University, 1-33 Yayoi Inage, Chiba, 263-8522, Japan*ykatagiri.17@chiba-u.jp
2
Salesian Polytechnic, 4-6-8 Oyamagaoka, Machida, 194-0215, Japan
3
Institute of Fluid Science, Tohoku University, 2-1-1 Katahira Aoba, Sendai, 980-8577, Japan

ABSTRACT
Quantitative measurement of unsteady flow field around the test model installed in thewind tunnel is investigated using Background Oriented Schlieren (BOS) technique. The reentry capsule is planned to use in the sample return mission, which plans to collect theastronomical sample and bring it back to our planet. Understanding the unsteady and complex
flow field around flying objects like the re-entry capsule in transonic flow is very important [1].
In the previous study, computational fluid dynamics (CFD) and qualitative experiments suchas the schlieren method are mainly used to find out flow field characteristics. We have studied
the BOS technique that is remarked as a quantitative experimental method using a simple
optical setup and image analysis [2]. However, this method was hardly used in the transonicflow because of its sensitivity. Therefore, the BOS technique with telecentric optical system [3]and digital projector is introduced in this study. They enable not only to obtain a parallel
projection of the flow field and test model but to adjust the distance from the background to thetest model. As a result, the sensitivity of the BOS technique is improved, and quantitative
experiment visualization is achieved. Visualization of the unsteady flow field around the reentry capsule model shows flow separation from the front shoulder part of the capsule and flow
disturbance in the wake region. Thanks to quantitative visualization, unsteady flow
characteristic around the capsule model can be compared with oscillation of the model, and therelation between them is revealed.
REFERENCES[1] Masayuki Nomura, Koji Fujita, and Hiroki Nagai., “Experimental Study of a Re-entry
Capsule to Reduce Self-excited Oscillation at Transonic Speed”, the 39th Aerospace
Numerical Simulation Symposium, 2021
[2] Meier GEA. Computerized background-oriented schlieren. Exp. Fluids Vol. 33, 2002, pp
181-187.
[3] Masanori Ota, Friedrich Leopold, Ryusuke Noda, Kazuo Maeno. Improvement in spatial
resolution of background-oriented schlieren technique by introducing a telecentric opticalsystem and its application to supersonic flow. Exp. Fluids Vol. 56, 2015

PSFVIP13-66

ULTRASOND VECTOR PROJECTILE IMAGING
OF URINARY FLOW DYNAMICS
Takuro Ishii
Frontier Research Institute for Interdisciplinary Sciences, Tohoku University
6-3 Aramaki Aza Aoba, Aoba ward, Sendai, Miyagi 980-8578 Japan
takuro.ishii@tohoku.ac.jp

ABSTRACT
Lower Urinary Tract Symptoms (LUTS) is a major age-related disease caused by changes inmechanical and physiological properties of the bladder and the urethra, such as benign prostatic
hyperplasia (BPH). Yet, it is difficult to directly observe the shape of the urinary tract and their
hydraulic effects to the internal urinary flow because the present in-vivo flow imaging modality(e.g., color Doppler imaging) does not have a sufficient time resolution to image the large
deformation of the urinary tract in the beginning and ending phases of the voiding or is notcapable of quantitatively measuring the multi-directional flow in the curved and obstructedurinary flow tract. Thus, this study aimed to develop a novel urodynamic flow imaging modality
based upon an ultrasound high-frame rate vector flow imaging technique, Vector Projectile
Imaging (VPI) [1].
The urodynamic flow imaging system was built using a research-purpose ultrasound platform(Vantage 128, Verosnics, Inc., WA, USA) equipped with a custom-made transrectal linear
probe (L10-5TR192V, Okusonic corp., Saitama, Japan). In addition, an original ultrasoundimaging framework, Uro-VPI [2], was implemented on the system. In general, the ultrasoundplatform was configured to emit unfocused ultrasound pulses from -10 and 10 degrees oftransmit steering angles alternatively to acquire Doppler shift maps of respective beam
direction, and those multiple Doppler data was processed to visualize time-resolved flow
vectors that depicted the spatio-temporal distribution of flow direction and speed. The efficacyof the developed system was tested in male patients with lower urinary tract symptoms.
The experiments showed the Uro-VPI system was capable of clearly visualizing the transientand complex urinary flow dynamics, such as formation of jet and vortex flow patterns at the
obstruction in the urethra. This new flow visualization modality in urology would provide
deeper insights into the hydrodynamic mechanisms causing LUTS.
REFERENCES[1] Yiu, B., Lai, S., Yu, A., “Vector Projectile Imaging: Time-resolved Dynamic Visualizationof Complex Flow Patterns”, Ultrasound Med Biol, Vol. 40 (2014), pp. 2295-2309.
[2] Ishii, T., Nahas, H., Suzuki, K., Yiu, B., Chee, A., and Yu, A., “Contrast-Enhanced
Urodynamic Vector Projectile Imaging (CE-UroVPI) for Urethral Voiding Visualization:
Principles and Phantom Studies”, Urology, Vol. 140 (2020), pp. 171-177.

PSFVIP13-67

COMPARISON OF STRAIGHT-SWIMMING PERFORMANCE OF PITCHINGWING BETWEEN STEADY AND PERIODIC FLOWS*Y. Isoda1, Y. Tanaka2
1

Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto-shi,
Kyoto-fu 606-8585 Japan
2
Faculty of Mechanical Engineering, Kyoto Institute of Technology, Kyoto-shi, Kyoto-fu
606-8585 Japan*d1821003@edu.kit.ac.jp

ABSTRACTIn this study, we investigated the difference in the straight-swimming performance of thepitching wing between steady and periodic flows, where the periodic flow is a time-varying
freestream velocity in the mainstream direction, and the pitching wing is a NACA 0012 airfoil
rotating about its quarter chord point. The swimming performance is evaluated using mean
thrust and lift coefficients. For instance, the pitching wing can swim straight in the forward
direction at positive thrust and the zero lift coefficient. The thrust and lift coefficients were
calculated by open-source computational fluid dynamics (CFD) software OpenFOAM. The
CFD was carried out under the conditions of Reynolds number of 4130. The Strouhal numberof periodic flow, Stp, is 0.5, and that of the pitching wing, Stw, is 0.5, 1, 1.5, and 2. The mostimportant parameter is the frequency ratio, k (= Stw/Stp), between the pitching wing and periodic
flow. In present conditions, the frequency ratio, k, becomes 1, 2, 3, and 4. We consider thesteady flow as a special case of periodic flow at a velocity amplitude of zero.
In steady flow, the thrust coefficient increases with increasing frequency ratio, k, and the lift
coefficient are 0.00, 0.00, 0.00, and 0.89 at each frequency ratio, k. At k = 4 (or Stw = 2), the lift
coefficient switches from zero to 0.89, and the wake becomes asymmetry. This phenomenon iscalled wake deflection [1]. In periodic flow, the thrust tendency to frequency ratio is the sameas the steady case. The lift coefficient is 0.32, 0.00, 0.00, and 0.80 at each frequency ratio. At k
= 4 (or Stw = 2), the lift coefficient is non-zero (0.80). That is the same as the steady case.
However, lift coefficient is also non-zero (0.32) at k = 1. In conclusion, we found that thepitching wing in steady flow can swim straight at frequency ratio of 1, 2, and 3. In contrast, thepitching wing in a periodic flow can swim straight at frequency ratio of 2 and 3.

REFERENCE[1] Yu, M., Hu, H., and Wang, Z., “Experimental and Numerical Investigations on the
Asymmetric Wake Vortex Structures of an Oscillating Airfoil”, In 50th AIAA aerospacesciences meeting including the new horizons forum and aerospace exposition, (2012), p.
299.

PSFVIP13-68

INFLUENCE ON THERMAL IMPEDANCE ALONG HEAT TRANSFER PATH
OF POWER SEMICONDUCTOR PACKAGE BY COPPER PAD
ON PRINTED CIRCUIT BOARD*K. Nishi1
1

Ashikaga University, 268-1 Omae-cho, Ashikaga, Tochigi 326-8558 Japan*nishi.koji@g.ashikaga.ac.jp

ABSTRACTPower electronics technologies are becoming more important than before with motor
application expansion. Motor drive system with three-phase inverter circuit is becoming
common to meet high controllability and lower power consumption demands. Especially,adequate thermal design is vital to enable inverter integrated motor drive system with lightweight and small size. To realize adequate thermal design, heat transfer structure of the system
is required to be grasped and its visualization technique is important.
There is one way to visualize heat transfer structure of the system by utilizing thermal
impedance distribution. In previous research [1], a methodology to obtain thermal impedance
distribution along heat transfer path is proposed. Transient junction temperature is measured byutilizing temperature-sensitive parameter and thermal impedance distribution is obtained by
optimizing thermal resistance and heat capacitance parameters of Cauer thermal network which
minimize junction temperatura prediction error.
In this paper, this methodology is applied to two test boards with power semiconductor devices
which employ a type of surface mount type package, “DPAK”. Each test board has different
copper pad configuration and the influence on thermal impedance by copper pad configuration
is discussed.
REFERENCES[1] Nishi, K., “A Methodology to Extract Thermal Impedance Distribution along Whole Heat
Transfer Path”, Journal of The Japan Institute of Electronics Packaging, Vol. 24, No. 6(2021), pp. 551-559 (In Japanese).

PSFVIP13-69

EXPERIMENTAL STUDY OF THERMAL CONVECTION BY HEATING AND
COOLING THE SIDE OR TOP SURFACE OF A ROTATING CYLINDRICALVESSELK. Shimoura1, *T. Ihara1, T. Noguchi1 and K. Hirata1
1

Doshisha University, 1-3 Tatara-miyakodani, Kyotanabe-shi, Kyoto 610-0321, Japan*cguc4017@mail4.doshisha.ac.jp
ABSTRACTThe objective of this study is to experimentally investigate a rotating flow field in a rotating
cylindrical vessel. Among the secondary flows from the most basic rigid-body rotational motion
generated in the rotating fluid in the cylindrical vessel, one has the columnar structure thatappears from the water surface to the bottom we suppose that the former secondary flow could
be related with the cooling of the top surface, and the latter secondary flow could be relatedwith the heating and cooling of the side wall, and another has the vortex structure that appears
just near the side wall.
As well as by Fowlis & Hide (1965) and Hide & Mason (1970), we made a regime diagramwith two dimensionless quantities such as the thermal Rossby number RoT and the Taylor
number Ta, observing visualized flow using Aluminum flakes. We also check whether thecolumnar flow structure is thermal convection or not, and investigate methods to prevent thegeneration of the two secondary flows.
We summarized the experimental results with various vertical temperature differences in a mapof depth versus rotation speed, comparing with a transformed equation of the approximate
equation for the critical Rayleigh number by Chandrasekhar (1953). We summarized theexperimental results with various horizontal temperature differences in a regime diagram of
RoT against Ta, comparing with the experimental results by Fowlis & Hide (1965) and Hide &Mason (1970).
As a result, it was found that the columnar structure is related with the thermal convection due
to vertical temperature difference caused by vapor cooling from the top water surface, and thatthe occurrence of the columnar structure could be suppressed by placing the lid on the top water
surface in the cylinder. It was also found that the vortex structure just near the side wall in oneof several regimes is related with thermal convection due to the horizontal temperature
difference. The thermal convection due to the horizontal temperature difference may be indifferent regimes due to heating or cooling of the side wall, and the temperature difference must
be controlled by heating and cooling of the side wall below 0.05 K except for the condition
where Ta is more than 108.
REFERENCES[1] Fowlis, W. W. and Hide, R., Thermal convection in rotating annulus of liquid: effect ofviscosity on the transition between axisymmetric and non-axisymmetric flow regimes,
Journal of the Atmospheric Sciences, Vol. 22, No. 5 (1965), pp. 541–558.
[2] Hide, R. and Mason, P., Baroclinic waves in a rotating fluid subject to internal heating,Philosophical Transactions of the Royal Society of London, Series A, Vol. 268 (1970), pp.
201–232.
[3] Chandrasekhar, S., The instability of a layer of fluid heated below and subject to Coriolis
forces, Proceedings of the Royal Society of London, Series A, Vol. 217 (1953), pp. 306–
327.

PSFVIP13-70

STUDY ON DRAG COEFFICIENT FOR CIRCULAR PLATE WITH HOLES*K. Namba1, Y. Kubota1 and O. Mochizuki 1
1

Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 Japan*mangetu2015@gmail.com

ABSTRACTThe estimation of drag coefficient can be written as CD = 2D/(ρu2A). Here, CD is dragcoefficient, D is drag force, ρ is density of fluid, u is flow velocity and A is the characteristic
area. The drag coefficient is different with the shape of objects. Furthermore, the dragcoefficient of annular plate as circular plate with hole is larger than the circular plate withouthole [1]. The size of hole relates the magnitudes of drag coefficient. The previous study
obtained the drag coefficient of circular plate with holes during the free-falling [2]. They
reported that the drag coefficient increased with the increase of aperture ratio and the numberof holes in a circular disk. Now we have a question, why does the drag coefficient of circular
disk with holes increasing compared with circular plate without holes? We have carried out thedrag force measurement and visualization under the steady condition to answer this question.
In our experiment, drag force measurement and flow visualization around the circular disk withholes were investigated. The experimental models were obtained from the number of holes andaperture ratio. Number of holes is 3, 4 and 6, and aperture ratio are 0.1, 0.2 and 0.3 respectively.
Measurement of drag coefficient was carried out with towing in 4000x 500x 500mm water tankand momentum sensor.
The results show that the increase of both the number of holes and the aperture ratio showed
the increase of drag coefficient. This result is agreed with previous result [2]. The results fromflow visualization showed that the jet flow from the holes in a circular plate. This suggested thereason of increasing the drag coefficient of circular plate with holes. From the comparison ofthese results, the drag coefficient was increased with the summation of circumference of holes
in model. This result suggests the effect of shear flow caused by the jet ejected from the holes
in a circular disk. The details of these results will be shown in the presentation.
REFERENCES[1] The Japan Society of Mechanical Engineering., Mechanical Engineers’ Handbook
Fundamentals, 1st Edition, Maruzen Publishing Co., Ltd, (2007), pp. α4-85.
[2] Naoki, H. and Yoshihiro, K., “Flow around circular plate with holes”, The Japan Societyof Mechanical Engineering Journal, (2020).

PSFVIP13-72

EFFECT OF SURFACE WETTABILITY FOR DISK FRCTION ON ROTATINGDISK IN CENTRIFUGAL IMPELLER*Kento Sakai 1, Yumeno Inaba1 and Kazuyoshi Miyagawa 1
1

Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan*kent2916@fuji.waseda.jp

ABSTRACTThe disk friction loss is a major issue for high efficiency for industrial pumps since the disk
friction loss increases remarkably in the low specific-speed pump. Flow fields in narrow
clearance between rotating disks and stationary disks are theoretically analysed [1]. Moreover,Watanabe et al. [2] developed a drag-reduction method using the spiral grooves on the disk
surface. However, it has few examples of the practical application though various kinds of study.
This research focuses on the relationship between surface wettability, internal flow, and disk
friction loss. The hypothesis that the effect of disk friction reduction could be obtained bycontrolling the wettability of the disk surface was tested by the experimental method.
The test disks were chemically coated with a thickness of about 3μm. The Ad-tech coating andthe Cytop coating were selected for hydrophilic coating and for hydrophobic coating,respectively. The measured contact angles were about 14° for the hydrophilic coating and about
110° for the hydrophobic coating. Using the rotating disk with these coating and without coating,the torque and pressure measurement test was performed, and the results are compared. The
closed-loop experimental apparatus simulates the clearance flow between a rotating impeller
and a stationary casing as such in centrifugal pumps. Measurements of friction torque andpressure distribution in radial direction were conducted in various testing conditions changing
rotational speed, flow rate and water temperature. In addition, the flow field was simulated bysolving the unsteady RANS equations by three-dimensional computational fluid dynamics
simulations to compare with the experimental results. The Shear Stress Transport k-omega
model was used to include the effects of turbulence model.
Experimental results show radial pressure distribution are almost same between the surface withhydrophilic/hydrophobic coating and without coating. These results suggest that the flow fieldin the clearance are nearly unchanged depending on the surface wettability. On the other hand,when we organized the disk friction coefficient calculated from the measured torque by therotating Reynolds number, the disk friction coefficient with coating is smaller than without
coating, regardless of the hydrophilic/hydrophobic effects. It should be additionally noted that
effects of coating for friction reduction is greater when the Reynolds number is smaller.
In conclusion, our experimental results provide the evidence for the reduction of the disk
friction loss by controlling the wettability of the surface.
REFERENCES[1] Daily, J.W. and Nece, R.E.,“Chamber Dimension Effects on Induced Flow and Frictional
Resistance Enclosed Rotating Disks”, ASME Journal of Fluid Engineering, Vol.821(1960), pp.217-230.
[2] Watanabe, K., Budiarso, Ogata, S. and Uemura, K., “Drag Reduction of an Enclosed
Rotating Disk with Fine Spiral Grooves”, Journal of Environment and Engineering,
Vol.2(2007), No.1, pp.97-107.

PSFVIP13-73

VISUALIZATION OF SHOCK WAVES ABOVE WATER DRIVEN BY WATER
ENTRY USING SHADOW GRAPH METHOD*Y. Ebii1, T. Kikuchi1 and A. Muramatsu1
1

Nihon University, 7-24-1 Narashinodai, Funabashi, Chiba 274-8501, Japan*csys21009@g.nihon-u.ac.jp

ABSTRACTThe high-speed water entry phenomenon is a complicated unsteady flow, which involves awater splash, an underwater shock wave, an underwater projectile, and an underwater cavity.
We are interested in physics of this complicated phenomena. A shock wave in air above water
also occurs even when the entry speed is less than the speed of sound in the air[1]. We guessthat this shock wave affects phenomena above water phenomena and causes a threshold value
between low-speed and high-speed. In order to confirm the entry speed at which a shock wave
above water begun to be generated, 5.97 mm diameter plastic resin spheres were launched at
different entry speeds. The flow fields above water were optically visualized by the shadow
graph method. Although a week shock wave above water was observed at the entry speed 55.19
m/s, this shock wave attenuated and disappeared on next video frame. The propagation velocityof the shock waves above water at entry speeds of 69.15-152.8 m/s were calculated from theresulting sequence photographs. The shock propagation velocities were almost constant at lessthan 130 m/s of the projectile entry speed. The shock propagation velocities increased linearlywith respect to the entry speed at greater than 130 m/s of the entry speed. Therefore, theinfluence of shock waves above water on water-surface phenomena may not be negligible atentry speeds of 130 m/s or higher. The entry point was enlarged and optically visualized theinception of shock waves above water by the same way. Some initial shock waves were attachedto the water splash at entry speeds of 125-152.8 m/s. It was guessed that the initial speed of thewater splash exceeded the speed of sound in air.

REFERENCES[1] Kikuchi, T. and Takayama, K. The influence of the entry speed to flow field above water
surface on the water entry phenomenon, International Journal of scientific and technicalresearch in engineering, Vol 2, Issue 12, 2017.

PSFVIP13-74

DEVELOPMENT OF HIGH-RESOLUTION PSV USING CODED ILLUMINATION
AND FEATURE MATCHING ALGORITHM*Yusaku Tsukamoto1, Shumpei Funatani1
1

University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan*g21dts03@yamanashi.ac.jp

ABSTRACTPSV is a high-resolution flow velocimetry method using a digital SLR camera, and its spatial
dynamic range is one order of magnitude higher than that of PIV. Several recent studies
proposed new PSV methods to measure flow fields that cannot be measured by PIV or PTV.
Wang et al. developed a new measurement technique named CSPSV using a color illumination
system and applied it to a large-scale 3D measurement (1.5 m × 1.4 m × 0.8 m in width × height× depth) using two digital SLR cameras [1].
We developed an analysis method to detect particle trajectories using a feature matchingalgorithm to improve the resolution of PSV. Feature matching algorithms are well known as
one of the image recognition techniques, and this study used the KAZE algorithm [2] to findkey points and matched them by the k-nearest neighbor algorithm (k-NN algorithm). In addition,
the direction of particle flow was recorded in the visualized image by using the codedillumination method proposed by Khalighi et al [3].
In this study, we first verified the validity of the trajectory detection methods using the KAZE
and k-NN algorithms in advance by using synthetic images that artificially simulate thetrajectory of particles captured by the coded illumination method. In the next validation, theapplicability of the KAZE and k-NN algorithms to actual airflow measurements was evaluatedusing a device that generates a swirling airflow. The optical system consists of a semiconductor
laser (continuous wave laser, 532 nm, 1 W) and a high- resolution digital SLR camera (image
size: 6000 × 4000 pixels), and the illumination timing of the laser is controlled by a TTL signal.
The validation results show that the coded illumination method can successfully visualize
asymmetric particle trajectories from swirling flows, and that the KAZE and k-NN algorithms
can detect trajectories in the visualized images.
REFERENCES[1] Wang, H., Li, X., Shao, X., Wang, B., and Lin, Y. “A colour-sequence enhanced particle
streak velocimetry method for air flow measurement in a ventilated space.”, Building andEnvironment, Vol. 112, No. 1 (2017), pp. 77-87.
[2] Alcantarilla, P.F., Bartoli, A., and Davison, A.J. “KAZE features.”, In: 12th European
conference on computer vision, Italy, (2012), pp. 214-227.
[3] Khalighi, B., and Lee, Y.H. “Particle tracking velocimetry: an automatic image processing
algorithm.”, Applied Optics, Vol. 28, No. 20, (1989), pp. 4328-4332.

PSFVIP13-75
DETECTION OF LARGE-SCALE STRUCTURES IN A TEMPORAL ROUND JETUSING MULTIDIMENSIONAL DYNAMIC MODE DECOMPOSITION*M. Takahashi1, R. Fukui1, K. Tsujimoto1, T. Ando1 and T. Shakouchi1
1

Mie University, 1577 Kurimamachiya-cho, Tsu-shi, Mie 514-8507 Japan*takahashi@mach.mie-u.ac.jp
ABSTRACT

Numerical simulations reproducing the turbulent flows generated in the laboratory using windtunnels or water channels are called spatially-developing simulations, which often require large
computational domains and long computation times for convergence of statistics. In this respect,
temporally-developing simulations can save computational resources and have been used inmany studies of shear flows.
Round jet in a temporally-developing simulation (temporal round jet) obtains the streamwise
homogeneity in exchange for temporal stationarity. In a cylindrical coordinate system, thetemporal round jet is not only homogeneous but also periodic in both streamwise and azimuthal
directions. Thus, the flow field of the temporal round jet is expected to be decomposed into
spatially oscillating modes. Dynamic mode decomposition (DMD) provides the modal
decomposition according to the temporal or spatial oscillation. In recent years, DMD has beenfurther generalized for multidimensional oscillation analysis, which is originally documented
as Spatio-temporal Koopman decomposition[1]. This enables us to analyze the dominating
structures in a temporal round jet based on the streamwise and azimuthal oscillations.
It is considered that the helical large-scale structures are dominant in the far-field of round
jets[2]. In this study, we use the multidimensional DMD to detect the dominant large-scale
structures in a temporal round jet. The jet is generated in a cubic computational domain whose
length in all three directions is 4πDE, where DE is the initial diameter of the jet core. The jet
Reynolds number is 2500. Consequently, we demonstrate that the large-scale structure in thepresent temporal round jet consists of single- and double-helical structures, which is in good
agreement with that supposed by the existing experimental results.

REFERENCES[1] Le Clainche, S. amd Vega, J. M., “Spatio-Temporal Koopman Decomposition”, Journal of
Nonlinear Science, Vol. 28, No. 5 (2018), pp. 1793-1842.

[2] Samie, M., Lavoie, P. and Pollard, A., “Quantifying eddy structures and very-large-scale motions
in turbulent round jets”, Journal of Fluid Mechanics, Vol. 916, No. 10 (2021), A2.

PSFVIP13-76

HEAD-ON VORTEX RING COLLISIONS UPON SMALL LATTICE POSTS*Daniel Tze How New1, Chuanhua Liu2, Darius Koi Yik Tham2, Bowen Xu 1and Haotian
Li31

School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50
Nanyang Avenue, 639798, Singapore
2
NUS High School of Mathematics and Science, 20 Clementi Avenue 1, 129957, Singapore
3
VOMMA (Shanghai) Technology Co. Ltd, Nerobay 1, 951 Jianchuan Road, Shanghai,
China

ABSTRACTAn experimental time-resolved particle-image velocimetry study had been conducted in wateron round vortex rings colliding head-on with surfaces with lattice posts. The vortex rings weregenerated by an impulsively started piston driven by a stepper motor, where “cylindrical waterslugs” were ejected out of a d=20mm round nozzle. The Reynolds numbers of the vortex rings
range from Re=Ud/=1000 to 4000, where U is the mean piston velocity and  is the kinematic
viscosity of water. The lattice posts comprised of circular cylinder with diameters of 1mm and
2.5mm, as well as spaced at 5mm and 10mm apart in a square grid. The research goal is to
study how effective these lattice posts and their different arrangements are in terms ofenhancing the breaking up of the primary vortex rings and mitigating the formations ofsecondary and tertiary vortex rings. Earlier study by [1] have shown that it is possible to control
head-on collisions between vortex rings and flat walls via lattice posts and thus motivated thepresent study. Findings from the study will have relevance in better understanding how strong
counter-rotating vortices, such as those produced by aircraft wing-tips, may be encouraged todissipate faster through the use of similar physical structures strategically located by the sidesof airport take-off runways. Results from the study reveal that the lattice posts are able todissipate the various vortex ring structures faster than when no lattice posts are present (see [24] for latter), with the dissipation rate/behaviour depending on the post diameter and spacing.
References[1] Li, Q., & Bruecker, C. H. (2018). Vortex interaction with a rough wall formed by ahexagonal lattice of posts. Physics of Fluids, 30(5), 054107.
[2] Verzicco, R., & Orlandi, P. (1994). Normal and oblique collisions of a vortex ring with awall. Meccanica, 29(4), 383-391.
[3] Cheng, M., Lou, J., & Luo, L. S. (2010). Numerical study of a vortex ring impacting a flat
wall. Journal of Fluid Mechanics, 660, 430-455.
[4] New, T. H., Shi, S., & Zang, B. (2016). Some observations on vortex-ring collisions upon
inclined surfaces. Experiments in Fluids, 57(6), 1-18.

PSFVIP13-77

ADAPTIVE WINDOW TECHNIQUE FOR LIFETIME-BASED TEMPERATURE
AND VELOCITY SIMULTANEOUS MEASUREMENT USING THERMOGRAPHICPARTICLE TRACKING VELOCIMETRY WITH A SINGLE CAMERA*T. Cai, J. Han, M. Kim, J. Jung and †K.C. Kim

School of Mechanical Engineering, Pusan National University, Busan, 46241, Korea.
†
kckim@pusan.ac.kr

ABSTRACTThe simultaneous measurement of temperature and velocity in the fluid has been attracted
increasing interest as it could provide synchronized temperature and velocity information,
which is important in the basic research on fluid mechanics and thermodynamics. As one of theeffective velocity and temperature simultaneous measurement methods, thermographic
PIV/PTV[1] has experienced rapid development in recent years as its outstanding capability invarious application areas, wide temperature range, and in-situ measurement.
The most widely used thermographic PIV/PTV method is the intensity-ratio-based method[2].
Although this method is relatively mature and has been applied in film cooling, combustion,and other applications, it still has many obvious shortcomings including 1) susceptible tosurrounding light such as multiple scatters and near-wall reflections, 2) its expensive solutionin which several lasers and cameras are needed, 3) cumbersome process: aligning several laser
sheets will be difficult, and since two different viewing angles are used, a correction is needed.
Compared with the intensity ratio method, the lifetime method[3] has been proven to have higher
temperature measurement accuracy in the field of surface temperature measurement because of
its self-referencing characteristics. In addition, the single camera-based measurement could
reduce the cost and cumbersome arrangement to a certain extent. With the continuous
development of high-precision measurement requirements, it is necessary to develop a lifetimebased thermographic PTV/PIV. It will greatly reduce the difficulty of the measurement setup
and the cost of equipment while improving the measurement accuracy.
In this study, we proposed an adaptive window technique for lifetime-based temperature andvelocity simultaneous measurement using thermographic PTV with a single camera. Thismethod generates windows for calculating the phosphorescence decay lifetime constant by
capturing the position and velocity of phosphorescent particles. It overcomes the problem of
inaccurate temperature acquisition of dynamic particles in the traditional lifetime method.
Despite the disadvantages of sacrificing resolution and adding post-processing steps, the highprecision measurement results, single-camera realization, and application of moving targets
make it an alternative method for thermographic PTV measurement.
REFERENCES[1] Abram. C., Fond. B., Beyrau. F., Temperature measurement techniques for gas and liquid flows
using thermographic phosphor tracer particles, Progress in energy and combustion science, 64(2018)
93-156.
[2] Omrane. A., Juhlin. G., Ossler. F., and Aldén. M., Temperature measurements of single droplets byuse of laser-induced phosphorescence, Appl Opt, 43(2004) 3523-9.
[3] Someya. S., Uchida, M., Tominaga, K., Terunuma, H., Li. Y., and Okamoto. K., Lifetime-based
phosphor thermometry of an optical engine using a high-speed CMOS camera, International journal ofheat and mass transfer, 54(2011) 3927-32.

PSFVIP13-78

EXPERIMENTAL INVESTIGATION ON THE FLOW STRUCTURE OFBUOYANCY VORTICES USING PARTICLE IMAGE VELOCIMETRY*Z. Wang1, N.A. Hawkes1, M. MacDonald1, J.E. Cater2 and R.G.J. Flay1
1

Department of Mechanical and Mechatronics Engineering, University of Auckland, 1010,
New Zealand*zwan472@aucklanduni.ac.nz
2
Departement of Engineering Science, University of Auckland, 1010, New Zealand

ABSTRACTA buoyancy vortex is similar to many naturally occurring vortices, such as dust devils. For dust
devils, the source of buoyancy is from intense surface heating from solar radiation that can
result in strong winds with peak tangential velocities of approximately 10 m/s near groundlevel [1, 2]. Field measurements of atmospheric vortices have been complicated by unsteady
temperature gradients and unpredictable winds. To obtain a better understanding of the flow
structure of a buoyancy vortex, a laboratory investigation in a controlled environment isrequired without the influence of ambient conditions.
One of the earliest laboratory buoyancy vortex studies was by Mullen and Maxworthy [3],where the flow was visualised and measured using soap bubbles. However, the accuracy of theearly measurements and the flow visualisation near the vortex core were not ideal due to theshort survival time of the tracer particles and the limitations of the recording system. Therefore,
this study is intended to create a more holistic understanding of the flow characteristics aroundthe vortex core, the potential flows at the outer region, and the temperature-driven flow
structures using the particle image velocimetry (PIV) technique.
This research carried out a quantitative analysis to explore an artificial buoyancy-driven
columnar vortex at a laboratory scale. Based on experimental investigations using flow
visualisation [4] and PIV, the horizontal cross-section of the vortex at 0.6 m above the ground
was captured. The formation and decay stages of the vortex were visualised, and bothinstantaneous and time-averaged tangential and radial velocity profiles were derived from the
PIV results. The temperature profiles were also measured from thermocouples mounted at thesame height. A correlation was investigated between the temperature profile in the radial
direction of the vortex and the location of the peak velocity.
REFERENCES
1.
2.
3.
4.

Sinclair, P.C., Ph.D. Thesis, A quantitative analysis of the dust devil. 1966, The
University of Arizona.
Sinclair, P.C., The Lower Structure of Dust Devils. Journal of the Atmospheric
Sciences, 1973. 30(8): p. 1599-1619.
Mullen, J. and T. Maxworthy, A laboratory model of dust devil vortices. Dynamics ofAtmospheres and Oceans, 1977. 1: p. 181-214.
Hawkes, N. & Flay, R. & Cater, J. & MacDonald, M., Scaling of Experimental
Buoyancy Vortex Structures with Respect to Power Generation, 2020. Journal of
Physics: Conference Series

PSFVIP13-79
FREQUENCY RESPONSE OF
CARBON-NANOTUBE TEMPERATURE-SENSITIVE PAINT*T. Ikami1, 2, K. Takahashi1, Y. Konishi1 and H. Nagai1
1Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagiprefecture 980-8577, Japan*tsubasa.ikami.s7@dc.tohoku.ac.jp
2
Department of Aerospace Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai,
Miyagi-prefecture 980-8577, Japan

ABSTRACT
Temperature-sensitive paint (TSP) is a flow measurement technique that optically measures
global temperature distribution. TSP allows visualization of flow fields by measuring thetemperature difference caused by laminar and turbulent flows. The turbulent flow has a higher
heat transfer coefficient than the laminar flow. Therefore, the temperature distribution is formed
due to the heat transfer between the test model and flow when there is a temperature difference
between them.
Recently, cntTSP has attracted much attention. cntTSP is a combination of TSP and acarbon nanotube (CNT) layer for the thin internal heater. The CNT layer supplies constant heatto the model surface and a temperature difference occurs between the model and flow when avoltage is applied to the CNT layer. As a result, the laminar-to-turbulent boundary layertransition can be measured as the temperature difference. In previous studies, cntTSP has been
applied to unsteady flow field measurements in models in motion, such as pitch oscillations.
However, the quantitative response of cntTSP has not yet been evaluated to apply to unsteadyflow fields.
In this study, the frequency response of cntTSP was quantitatively evaluated by making
changes in the flow field by periodically introducing local disturbances to the boundary layer
on a flat plate using a loudspeaker. The turbulent wedge caused by the introduction of the local
disturbance was visualized as a low-temperature region, which indicates a large heat transfer
coefficient. Moreover, the temperature in the wedge-shaped region varied according to theperiod of introduction of the local disturbance. Furthermore, the amplitude of the temperaturefluctuation was quantitatively evaluated. The temperature amplitude decreased with theincrease in the frequency of the introduction of the local disturbance, and it reached O(10-3 K)
at 10 Hz.
REFERENCES[1] Ikami, T., Fujita, K., Nagai, H. and Yorita, D., “Measurement of Boundary Layer
Transition on Oscillating Airfoil using cntTSP in Low-speed Wind Tunnel”, Measurementof Science and Technology, 32 (2021), 075301, 11pp.
[2] Simon, B., Filius, A., Tropea, C. and Grundmann, S., “IR Thermography for Dynamic
Detection of Laminar-turbulent Transition”, Experiments in Fluids, 57:93 (2016).

PSFVIP13-80

LOCAL AND TRANSIENT HEAT TRANSFER MEASUREMENTFOR DROPWISE CONDENSATION USING TEMPERATURE SENSITIVE PAINTS*K. Matsushima1, T. Uchimura1, N. Sakoda1,2 and Y. Kita1,2
1Department of Mechanical Engineering, Kyushu University, 819-1395 Japan* k.matsushima@heat.mech.kyushu-u.ac.jp
2
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu
University, Japan
ABSTRACT
Condensation is a phase-change phenomenon in which vapor turns into liquid and used in many
applications such as electronic cooling, air conditioners and thermal power plants. On a solid
surface, condensation can occur in two modes: filmwise condensation, in which a liquid film isconstantly present, and dropwise condensation, in which the condensate liquid collects in theform of droplets. Dropwise condensation has been of considerable interest due to higher heattransfer coefficients than those of filmwise condensation. Although research is underway forthe industrial application of dropwise condensation, numerous researchers have focused on
droplet evolution and shapes, departure mechanisms and jumping phenomena withoutcompleting the task of actually evaluating local and transient heat transfer phenomena whichshould come along with the droplet behavior [1]. Understanding of such microscopic andtransient nature of dropwise condensation heat transfer is needed for the development of acomprehensive predictive model.
In this contribution, we develop a technique capable of simultaneously measuring temperature
distributions on a heat transfer surface and monitoring droplet behavior using TSPs
(Temperature-Sensitive Paints). TSPs are fluorescent paints that are excited by UV light andemit light with a longer wavelength. The temperature can be determined based on the intensityof the emitted light. As it can measure through materials that are opaque to IR with high spatial
and temporal resolution at low cost [2], TSP is more suitable for condensation experiment thanother methods such as IR cameras or thermocouples.
In our experiments, a thin titanium plate was used as the condensing surface and attached to asapphire substrate using an adhesive. Two TSP layers were created across the adhesive, and the
local heat flux was calculated using the temperatures measured at those two layers. As a result,
we have succeeded in capturing the TSP brightness changes coupled with droplet motion withhigh spatial resolution. We have demonstrated the potential of TSP-based local heat transfer
measurement for condensation research.
REFERENCES[1] El Fil, B., Kini, G. and Garimella, S., “A review of dropwise condensation: Theory,modeling, experiments, and applications”, Int. J. Heat Mass Transfer, Vol. 160 (2020),
120172.
[2] Al Hashimi, H., Hammer, C.F., Lebon, T.M., Zhang, D. and Kim, J., “Phase-Change Heat
Transfer Measurements Using Temperature-Sensitive Paints”, Journal of Heat Transfer,Vol. 140, No. 3 (2018), 031601.

PSFVIP13-83
VIDEO ANALYSIS ABOUT THE GLIMMER SYNCHRONIZATION OF
LUCIOLA PARVULA FIREFLIES*Shiro Kobayashi1, Nao Ninomiya1, Masayuki Iigo2 and Rion Tada1
1

Deptartment of Optical Engineering, Utsunomiya University, 7-1-2 Yoto, Utsunomiya 3218585 Japan*nino@utmu.jp
2Center for Bioscience Research and Education, Utsunomiya University, 350 Mine,
Utsunomiya 321-8505 Japan

ABSTRACT
It is known that the Luciola parvula fireflies clearly emit lights at regular time intervals andsynchronize between multiple males are observed, but the details of synchronization have notyet been clarified. Presently, we took videos of the luminescence phenomenon of multiple male
Luciola parvula fireflies and performed a correlation analysis on the details of the time changeof the luminescence brightness of each male Luciola parvula fireflies. The 12 Luciola parvula
fireflies are kept in glass wells so that each Luciola parvula fireflies can only moves in restricted
areas and their luminescence is recorded by a digital movie camera from above at the video rateof 30 fps. According to the preliminary study, each glimmer lasts about 3 frames and thus thetime series brightness is fitted by a parabolic function in order to give a precise timing of
maximum brightness. First of all, time intervals between glimmers of each Luciola parvula
fireflies are evaluated. Secondly, the glimmer correlation between different Luciola parvula
fireflies are investigated. As a result, it was clarified that the light emission cycle of Luciola
parvula fireflies is almost constant at 0.54 seconds, more than 70% of all light emissions aresynchronized and the order of synchronization is almost fixed with very small delay.
Consequently, it has been shown quantitatively that the glimmers of male Luciola parvula
fireflies are well synchronized. The synchronization of fewer individuals and thesynchronization to the external stimulus and many other aspects remain for the future study.
REFERENCES[1] Nakagawa, M. and Tanaka, H., “A Plausible Model of Synchrony in Pteropyx effulgens
and Its Occurrence Condition for Traveling Waves”, Journal of the Japan Society for
Industrial and Applied Mathematics, Vol. 29, No. 3 (2019), pp. 250-293.
[2] Hanson, F. E., Case, J. F, Buck, E. and Buck, J., “Synchrony and flash entrainment in a
New Guinea firefly”, Science, 174 (1971), 161–164.

PSFVIP13-84

TIME-RESOLVED PIV MEASUREMENTS OF FLOW FIELD AROUND A
BADMINTON SHUTTLECOCK DURING TURNOVER PROCESS*Y. Sakurai1, K. Nakagawa1 and H. Hasegawa1
1

Utsunomiya University, 7-1-2 Yoto, Utsunomiya-city, Tochigi 321-8585 Japan*mc216725@cc.utsunomiya-u.ac.jp

ABSTRACT
Badminton is one of the most popular sports in the world. The shuttlecock is used in badminton
game has the unique shape. The shuttlecock is truncated cone-shaped and consists of a cork,
gaps and a skirt portion. The shuttlecock has aerodynamic properties which differ from the ballused in other racquet sports. As an example of unique aerodynamic property, the shuttlecockshows high deceleration. It is known that the initial velocity immediately after smashing may
reach up to 137m/s (493 km/h) at maximum. The mechanism of high deceleration of the
shuttlecock was clarified in a previous study [1]. In addition, turnover refers to the flipping
experienced by a shuttlecock when undergoing heading change from nose pointing against theflight path at the moment of impact and a shuttlecock indicates the aerodynamically stablefeature for the flip movement just after impact [2]. In a previous study, the flow field around the
shuttlecock during turnover process was visualized [3]. However, the mechanism of turnoverstability of the shuttlecock has not been fully understood.
In this study, unsteady flow field during turnover process was investigated to clarify themechanism of turnover stability. In the present, we simulated the flipping motion by windtunnel experiments and visualized the flow field around the shuttlecock by a PIV technique.
It was confirmed that the flipping time in turnover process for the standard shuttlecock (withgaps) was shorter than that for the shuttlecock without gaps [3]. In the standard shuttlecock, theflow through the gap produces a vortex behind the shuttlecock, which increases the pressure
difference between the front and back of the shuttlecock and generates a restoring force. This
restoring force relates to the turnover stability.
REFERENCES[1] Hasegawa, H., Kitta, S., and Obayashi, S., “Flow analysis and aerodynamic characteristics
of a badminton shuttlecock with spin at high Reynolds numbers”, Sports Engineering,
Vol.16 (2011), 91-98.
[2] Cohen C., Texier B.D, Quere D., and Clanet C., “The physics of badminton”, New Journalof Physics, Vol.17 (1989), 063001.
[3] Nakagawa K., Hasegawa H., Murakami M., and Obayashi S., “Aerodynamic stability of abadminton shuttlecock”, Transactions of JSME (in Japanese), Vol.83(2017), No856.

PSFVIP13-85

UNSUPERVISED DEEP LEARNING OF THE STRUCTURAL CHARACTERISTICS
IN A TURBULENT CHANNEL FLOW AT A LOW REYNOLDS NUMBER*Mohammad Javad Sayyari 1, Jinyul Hwang1, Kyung Chun Kim1
1

School of Mechanical Engineering, Pusan National University, Busan 46241, Republic of Korea*sayyari@pusan.ac.kr

ABSTRACTIn this study, we examine the capability of an unsupervised deep learning network to capture
the spatial organization of large-scale structures in a turbulent channel flow at a low friction
Reynolds number. For this purpose, the Wasserstein generative adversarial network withgradient penalty (called GAN here for simplicity) is trained based on the cross-stream datasetof a direct numerical simulation (DNS) at the friction Reynolds number 𝑅𝑒𝜏 ≈ 180 to generate
artificial flow fields. Then, we explore the turbulence statistics and the corresponding coherent
structures using the generated flow fields. The generated flow fields show quite similar onepoint and two-point statistics when compared with those obtained from the DNS data. Further
analysis reveals that the GAN learns important structural information hidden in the training
data, such as the length-scale of the energetic motions, the spanwise distance of the low-speed
streaks in the logarithmic region, and the wall-normal variation of the integral length scales.
The success of GAN to predict these features inspires us to evaluate its capability to learn thespatial organization of the coherent structures. In this regard, we measure the size distributionof all the intense velocity structures identified in the instantaneous flow fields and find a very
good agreement between the DNS and GAN results. Then, we focus our study on the largescale structures and investigate their spanwise waviness and inclination angle with respect tothe horizontal axis as the cross-stream imprints of their large-scale meandering motion in thestreamwise direction. The relations among the waviness, inclination angle, width and height ofthe structures are discussed by computing their joint probability density functions. The results
show increasing waviness behaviour as the size of the structures increases. Also, it is observedthat the structures are almost symmetrically distributed around 0° when they are averaged
unconditionally. This is further analysed by conditionally averaging the identified structures,categorizing them into negative and positive clusters. The success of GAN to learn the structuralcharacteristics hidden in the turbulent flow fields in the low Reynolds number suggests its
potential to predict this information at a high Reynolds number and thus be utilized as an inflow
turbulence generator to provide instantaneous boundary conditions for more complicatedproblems such as spatially evolving turbulent boundary layers. This has a great potential for
reducing the computational costs of DNS related to a required large computational domain athigh Reynolds numbers. However, further studies are required to assess the GAN capability forpredicting the vortical structures associated with the coherent structures studied in this work.

PSFVIP13-86

VISUALIZATION AND MEASUREMENT OF INTERNAL FLOW IN A THINVORTEX CHUCK RESEARCH ON IMPROVEMENT OF SILICON WAFERADSORPTION PERFORMANCE* Naoyuki Fukaya 1 , Shumpei Funatani1, Katsuhiro Koshiishi 2 , Hitoshi Iwasaka 2
1

University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan*g22tm022@yamanashi.ac.jp
2
HARMOTEC CO., LTD., 4-1-32 Sumiyoshi, Kofu, Yamanashi 400-0851, Japan

ABSTRACT
Conventionally, silicon wafers and other semiconductor products have been transported bysuction or gripping in direct contact. However, direct contact with a wafer adversely affects thequality and characteristics of semiconductor products because it causes contamination of thewafer surface by fine particles and generates static electricity. Therefore, nowadays, noncontact transfer equipment using a swirling flow (hereinafter referred to as a vortex chuck) is
often used for transporting such precision semiconductors. In addition to the feature of noncontact work holding, vortex chucks have the advantages of not generating heat, not generatinga magnetic field, and having a simple structure. However, the effects on air flow and workpieces
have not been clarified for the thin vortex chucks that have been developed in recent years. In
this study, turbulent flow during suction by a vortex chuck was measured visually, and thelocations where turbulence occurs were evaluated.
A transparent acrylic plate was used as the work material for visualization. The air compressor
is connected to the vortex chuck via a regulator, pressure gauge, and valve. The supply pressure
was set at 0.2 MPa. The surface of the workpiece is uniformly coated with high-viscosity oil
and sprinkled with titanium dioxide powder as tracer particles. The gap between the workpieceand the vortex chuck was maintained at approximately 0.2 mm using a micrometer to adjust theheight of the workpiece.
Negative values tend to be observed near the wall of the vortex chuck, indicating that large
turbulence is generated by the sudden change in vorticity. At one location, the vorticity was 0.007 /ms, which is larger than the vorticity at other locations, indicating that the pressure isconcentrated. This suggests that the pressure distribution during suction by the vortex chuck isuneven, leading to a narrower suction range and reduced stability during suction retention.
As a result of visualization and measurement of turbulence during suction by the vortex chuck,it was confirmed that there were variations in turbulence energy due to the structure of thevortex chuck. In the future, we will study and fabricate a vortex chuck structure that improves
the stability of silicon wafer adsorption and retention based on the conditions of turbulence
generation.
REFERENCES[1] Li, X. Tokunaga, H., Cai, M., Funaki, T., Kawashima, K., Kagawa, T. “Research on a
non-contact handling system using swirling flow (1st Report: Basic characteristics of avortex chuck)”, Trans JFPS, Vol. 38, No. 1 (2007), pp. 1-6 (Japanese).

PSFVIP13-87
DEVELOPMENT OF VISUALIZATION TECHNIQUE FOR
HYDRODYNAMIC STRESS FIELD UTILIZING FLUORESCENT FORCE PROBE*R. Kuriyama1, R. Okamoto2, W. Yamamoto1, H. Kitakado3, S. Saito3,
K. Tatsumi1 and K. Nakabe1
1Graduate School of Engineering, Kyoto University, Kyotodaigaku-katsura, Nishikyo-ku,
Kyoto 615-8540 Japan* kuriyama.reiko.2m@kyoto-u.ac.jp
2
Faculty of Engineering, Kyoto University, Kyotodaigaku-katsura, Nishikyo-ku, Kyoto 6158540 Japan
3
Graduate School of Science, Kyoto University, Kitashirakawa Oiwake, Sakyo-ku, Kyoto
606-8502 Japan
ABSTRACTThe present study investigates the fluorescence response of a molecular force probe called
FLAP (flexible and aromatic photofunctional systems), which undergoes stress-induced
conformational change in elongational flow. We aim at developing a technique for visualizing
the hydrodynamic stress field in channel flow through fluorescence imaging of the FLAP force
probe. FLAP is composed of two rigid fluorescent aromatic wings fused with a flexible eightmembered ring (cyclooctatetraene). This molecule flexibly changes its conformation between
V-shape and planar shape in response to the external force. FLAP is excited by UV light andemits blue or green fluorescence depending on its conformation. We have visualized the tensile
force distribution during deformation of a polymer film through ratiometric fluorescenceimaging of FLAP doped in the film[1]. In the present study, the response of FLAP tohydrodynamic elongational stress was experimentally evaluated by measuring spatiallyaveraged fluorescence spectra and two-dimensional fluorescence images of FLAP solution in
microchannel flow. We used three types of FLAP whose molecular ends were chemicallyfunctionalized with PEG (polyethylene glycol) chains of different molecular weights (5000,
10000, and 20000), and their stress-responses were compared. Each FLAP-PEG was dissolvedin a dimethyl sulfoxide/glycerol mixture, and the solution was supplied to a sudden contraction
part of the microchannel at constant flow rates in the range of 2.2−446 µL/min. These flow
rates correspond to the elongational stress of approximately 0.1−20 kPa at 40 µm upstream ofthe entrance of the contraction part. The spectral measurements showed that the intensity ratioof green (529 nm) to blue (494 nm) fluorescence increased monotonically with the flow rate,
which indicates that the number of FLAP in planar shape increased with increasing elongational
stress. In addition, FLAP bearing the longest PEG chain showed the highest increasing rate of
the intensity ratio, which suggests the possibility of adjusting the stress sensitivity of FLAP bychanging the length of the PEG chain. In fluorescence imaging, two-dimensional distributionsof the fluorescence intensity ratio were visualized around the entrance of the contractions part.
The intensity ratio varied significantly in the region where the velocity gradient was large inthe streamwise direction.
REFERENCES[1] Kotani, R., Yokoyama, S., Nobusue, S., Yamaguchi, S., Osuka, A., Yabu, H. and Saito, S.,“Bridging pico-to-nanonewtons with a ratiometric force probe for monitoring nanoscale
polymer physics before damage”, Nature Communications, Vol. 13, No. 303 (2022), 9pp.

PSFVIP13-88

UNSTEADY PRESSURE DISTRIBUTION MEASUREMENT ON CYLINDER
SURFACE USING ANODIZED ALUMINUM PRESSURE-SENSITIVE PAINT
DURING SHOCK WAVE PASSAGE*S. Tamakuma1,2, K. Yomo1,2, T. Ogawa1 and H. Nagai1
1Institute of Fluid Science, Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai 980-8577,
Japan*shintaro.tamakuma.r7@dc.tohoku.ac.jp
2
Department of Aerospace Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku,
Sendai 980-8577 Japan
ABSTRACT

Pressure-sensitive paint (PSP) is an optical sensor that can measure the global pressure
distribution using the oxygen quenching of dye molecules. Anodized-aluminum pressuresensitive paint (AA-PSP) has excellent oxygen permeability and responsivity among various
PSPs and has been applied to visualize high-speed fluid phenomena. In order to capture such
ultrafast phenomena using PSP and a high-speed camera, the frame rate of the camera must be
fast, and the exposure time must be short to avoid blur. It is desirable for AA-PSP to have brightluminescence, high-pressure sensitivity, and fast response time. The time-response of AA-PSP
depends mainly on the lifetime of luminescence and oxygen diffusion in a pore of an anodized
aluminum layer[1].
Fujii et al. investigated the relationship between the electrolyte temperature and the poresize and depth[2]. The 90% rise time of their AA-PSP, the fastest time response to date is 0.81
µs. It has also been applied to visualize the interaction of a shock wave with a cylinder. However,the signal-to-noise ratio was poor, and image intensifiers were used due to the lack ofluminescence intensity.
In this study, we conducted the time response tests using the shock tube based on the resultsof luminescence intensity and pressure sensitivity investigations at different anodizing times
and dipping concentrations. In this test, the shock wave passing through the specimen coatedwith the PSP was visualized, and the rise time was calculated. When calculating the time
constant, the delay in the rise time caused by blurring of the shock wave surface due to exposure
time was corrected to calculate a more accurate time constant.
As a result, the 90% response time of this AA-PSP was approximately 2.6 µs.
This AA-PSP was applied to measure the unsteady pressure distribution on the cylinder surface
when the shock wave passed over the cylinder. This resulted in the time series visualizations of
the pressure distribution when the shock wave passed over the cylinder even under shooting
conditions with a frame rate of 50,000 fps and an exposure time of 1.0 µs.
Future work will include measuring the unsteady pressure distribution as the shock wave passes
through the cylinder and calculating the unsteady air force.
REFERENCES[1] Kameda, M., Tezuka, N., Hangai, T., Asai, K., Nakakita, K., and Amao, Y. “Adsorptive
Pressure-Sensitive Coatings on Porous Anodized Aluminium.” Measurement Science andTechnology, Vol. 15, No. 3, 2004, pp. 489–500.
[2] Numata, D., Fujii, S., Nagai, H., and Asai, K. “Ultrafast-Response Anodized-Aluminum
Pressure-Sensitive Paints for Unsteady Flow Measurement.” AIAA Journal, Vol. 55, No.
4, 2017, pp. 1118–1125.

PSFVIP13-89
DEVELOPMENT OF PRESSURE DISTRIBUTION MEASUREMENTTECHNOLOGY ON FREE-FLIGHT OBJECT SURFACE AT TRANSONIC SPEED*Y. Hosono1,2, K. Yomo1,2, K. Takahashi1, T. Ogawa1, K. Ohtani1 and H. Nagai1
1Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai,
Miyagi 980-8577 Japan*hosono.yota.q6@dc.tohoku.ac.jp
2
Department of Aerospace Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku,
Sendai, Miyagi 980-8577 Japan

ABSTRACT
A measurement technology using Pressure-Sensitive Paint (PSP) is developed to capture thesurface pressure distribution of an object during free flight at transonic speed. In a PSP
measurement, the pressure distribution is calculated by substituting the ratio of the pressureindependent image (reference image) and the pressure-dependent image (signal image) into thecalibration equation. However, in a measurement of unsteady motions, the reference image
required for the signal image changes in time. Therefore, it is necessary to adjust the position
and attitude of the object in the images. As a solution to this issue, a two-color PSP
measurement technology has been proposed, which enables simultaneous capturing of both
images [1]. On the other hand, this measurement is performed with a color camera, which isinferior in ISO sensitivity, and the signal-to-noise ratio is not sufficient.
Thus, this study aims to develop a measurement technology using the intensity-based method,which allows us to use a monochrome camera and measure with a higher signal-to-noise ratio.
Then, to capture a large number of reference images corresponding to the position and attitudeof the signal image in advance, we developed a system that automatically collects reference
images with 3-axis attitude control. The models measured were cylinder models (ϕ30 × 15 mm),and Hayabusa capsule models (1/16 scale), the surfaces of which were coated with anodized
aluminum PSP (AA-PSP). The models were flighted at a speed of M=1.1, and the luminescenceemissions of the PSP in flight were captured with a high-speed monochrome camera at a rateof 100 kHz. The captured data showed that the signal-to-noise ratio was more than 10 when the
exposure time was more than 3 μs.
REFERENCES[1] Sakaue, H., Miyamoto, K., and Miyazaki, T., “A motion-capturing pressure-sensitive paintmethod”, J. Appl. Phys. 113, 084901, (2013).

PSFVIP13-90

VISUALIZATION STUDY OF NANO PARTICLE BEHAVIOR WITHIN PORES*Y. Abe1, Y. Matsuda1
1

Department of Modern Mechanical Engineering, Waseda University, 3-4-1 Ookubo,
Shinjuku-ku, Tokyo 169-8555, Japan*ya-jupiter0309@toki.waseda.jp

ABSTRACT
Porous media are materials that have many pores inside, and they have the property ofadsorption of particles. Due to this property, porous media are widely used in industries.
Therefore, it is important to clarify how particles behave within pores. In this study, we
visualize nano particle behaviour within pores using single-particle tracking. Single-particle
tracking enables us to observe particles within the measurement object directly. For example,
single-particle tracking is used to reveal particle diffusion in a cell [1] and polymer layer [2],[3].
Moreover, we analyze particle behaviour using physical property values and find out uniquefeatures of particle behaviour within pores.
REFERENCES[1] Saxton M and Jacobson K, “Single-particle tracking: Applications to Membrane
Dynamics”, Annual Review of Biophysics and Biomolecular Structure, Vol. 26 (1997), pp.
373-399.
[2] Wöll D, Braeken E, Deres A, Schryver F, Uji-I H, and Hofkens J, “Polymers and single
molecule fluorescence spectroscopy, what can we learn?”, Chemical Society Reviews, Vol.
38 (2009), pp. 313-328.
[3] Iwao R, Yamaguchi H, Niimi T, Matsuda Y, “Single-molecule tracking measurement of
PDMS layer during curing process”, Physica A: Statical Mechanics and its Applications,Vol. 565 (2021), p.125576.

PSFVIP13-91
Development of Paddlewheel Aerator Performance Predictions Model* P. N. A. Nugroho1, M.A. Mustaghfirin1, D.S.A. Pambudi1, E. Novianarenti1,
D.A.Wulandari2 and S. Torii3
1 Politeknik Perkapalan Negeri Surabaya, 60111, Indonesia*priyambodo@ppns.ac.id
2 Department of Mechanical Engineering, Faculty of Engineering,

Universitas Negeri Jakarta, Indonesia.
3 Department of Advanced Mechanical System Engineering, Kumamoto University,

Kurokami, 2-39-1, Kumamoto 860-8555, Japan

ABSTRACTThe intensive aquaculture industry is mainly affected by the ability to maintain the water
quality, and low dissolved oxygen could be improved through the aeration process. The
paddlewheel aerator is one of the supporting devices required for the intensive aquaculture pond
system. The paddlewheel aerator still has a low aeration performance, resulting in higher
operational costs. This paper presents an analytical model to predict the optimal performanceof a paddlewheel aerator. The model considers the most influential factors affecting theperformance of the paddlewheel aerator. Then, Computational Fluid Dynamics (CFD) is
employed to simulate and validate the developed analytical model. The experimental model isalso performed to validate the result. The simulation results demonstrate that the model isaccurate enough to be used for estimating the paddlewheel aerator's optimal operational
condition.
Keywords: paddlewheel aerator, analytical model, experimental model

REFERENCES[1] World Resources Institute 2012 Coastal and Marine Ecosystems - Marine Jurisdictions: Coastline
length[2] Leung P, Carole R 2006 Shrimp Culture: Economics, Market, and Trade Wiley-Blackwell 5[3] Kooiman J 2005 Fish for Life: Interactive Governance for Fisheries Amsterdam University Press
94[4] Fast A 1992 Penaeid Growout Systems: An Overview Marine Shrimp Culture Amsterdam Elsevier
345-353[5] Boyd C 1998 Pond water aeration systems Aquacultural Engineering 18 1 9-40,[6] Moore J, and Boyd C 1992 Design of small paddlewheel aerators Aquacultural Engineering 11 1
55-69
[7] Boyd C, Torrans E, and Tucker C 2018 Dissolved oxygen and aeration in ictalurid catfish
aquaculture Journal of the World Aquaculture Society 49 1 7-70
[8] Boyd C, Darryl E, Chamberlain G Global Aquaculture 2006 Aerated pond management in
Operating Procedures for Shrimp Farming: Global Shrimp OP Survey Results andRecommendations, 1st ed. St. Louis, MO, USA: Global Aquaculture Alliance 68-75[9] Zhu D, Cheng X, Sample D, and Yazdi M 2020 Effect of intermittent aeration mode on nitrogenconcentration in the water column and sediment pore water of aquaculture ponds Journal ofEnvironmental Sciences 90 331-342[10] Hoagland R, Rouse D, Teichert-Coddington, and Boyd C 2001 Evaluation of automated aeration
control in shrimp ponds Journal of Applied Aquaculture 11 3 45-55

PSFVIP13-93

STUDY THE EFFECT OF DOWNSTREAM BLUFF BODY TO ENHANCE FIVBASED ENERGY HARVESTING, A VISUALIZATION STUDY*S. Hosseini1, *A. Afsharfard 2, K.C. Kim1
1

School of Mechanical Engineering, Pusan National University, Busan 46241, Republic of Korea
sajjad_hosseini@pusan.ac.kr
2
Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iranafsharfard@um.ac.ir

ABSTRACTWith the global population swelling and industrialization on the rise in developing nations,humanity’s hunger for energy has reached to unprecedented levels. As a results different typesof the energy harvesters are developed by researchers within the last three decades and it isremained as a necessary topic for global needs. In this study a modified Flow Induced Vibration(FIV) based energy harvester is presented. In this system, effect of employing the second bluff
body behind of a nature-inspired FIV-based energy harvester is studied. In doing so
multidisciplinary research that studies the following contents is presented:(a) experimentally studying the approaches to increase amplitude of FIV(b) utilizing the enhanced vibrations to extract energy
In this way, to increase the oscillation amplitude of bluff body and consequently increase in theenergy harvesting, the near-wake flow is studied comprehensively using smoke and laser flow
visualization and Particle Image Velocimetry (PIV). Then the electromechanical equation of
motion for the piezoelectric vibration-based energy harvester is derived. The experimentally
validated electromechanical equations of motion are used to study the FIV-based energy
harvesting.
REFERENCES[1] Lam, K., Wang, F. H. & So, R. M. C., 2004. Three-dimensional nature of vortices in thenear wake of a wavy cylinder. Journal of Fluids and Structures, Volume 19, pp. 815-833.
[2] Xia, C. et al., 2018. POD analysis of the wake behind a circular cylinder coated with porous
media. Visualization Society of Japan, Volume 21, pp. 965-985.

PSFVIP13-94

FSI-BASED DESIGN OF A DVA FOR DECREASING UNDESIRED VIBRATIONS
OF A ROTATING BEAM, A VISUALIZATION STUDY*A. Shahsavari1, *A. Afsharfard2, K.C. Kim1
1

School of Mechanical Engineering, Pusan National University, Busan 46241, Republic of Korea
amirreza @pusan.ac.kr
2
Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iranafsharfard@um.ac.ir

ABSTRACTIn this study, a Dynamic Vibration Absorber (DVA) will be designed to decrease undesired
lateral vibrations of a rotating beam like wind turbine blade. To do so, the effect of aerodynamic
forces on the dynamic response of the rotating beam will be studied. Then the DVA is designed
according to the Fluid Solid Interaction (FSI) content. In other words, the dynamic behaviourof the rotating beam is studied from the following perspectives:••

Effects of attaching or detaching the DVA on its dynamic response
Effect of using the DVA on the aerodynamics of the rotating beam

For studying the dynamic effect of the DVA on the vibratory behaviour of the rotating beam, it
is analytically modelled using the Euler Bernoulli model with presence of lateral excitation.
The dynamic effect of DVA is considered as an external force, and its application for decreasing
lateral vibration is studied. Then, the aerodynamic effect of attaching the DVA to the rotating
beam is experimentally studied. The experiments were performed in a wind tunnel at a speedof 1.1 m/s on two models of the antenna with and without DVA on the surface of the rotating
beam. Smoke and laser flow visualization was used to better understanding the effect of
attaching the DVA on the flow over the rotating beam. The flow visualization tests were
performed in two sections, one section perpendicular to the surface of the antenna, and theantenna surface section at three different angles. Changes in flow over the rotating beam andthe wake region were also examined and compared by flow visualization results. Finally, thegeometry of DVA is changed to improve the aerodynamic properties of the rotating beam anddecrease its undesired lateral vibration.
REFERENCES[1] Zhang, Mingjie, and Fuyou Xu. "Tuned mass damper for self-excited vibration control:
Optimization involving nonlinear aeroelastic effect." Journal of Wind Engineering andIndustrial Aerodynamics 220 (2022).
[2] Zhang, Zili. "Optimal tuning of the tuned mass damper (TMD) for rotating wind turbine
blades." Engineering Structures 207 (2020).

PSFVIP13-95
IMPROVEMENT IN ACCURACY OF THE BACKGROUND ORIENTEDSCHLIEREN TECHNIQUE WITH PARALLEL PROJECTION*N. Kosaka1, Y. Igari1, Y. Katagiri1, M. Yamagishi1, M. Ota1
1

Chiba University, 1-33 Yayoi Inage, Chiba, 263-8522, Japan*nao.kosaka@chiba-u.jp

ABSTRACTVisualization of supersonic flow field around the test model is important in thedevelopment of aircraft and spacecraft. The schlieren or shadowgraph methods have beencommonly used as visualization methods. These methods measure the refractive index change
in the medium as brightness change in the image plane due to the refraction of the light ray. If
the density can be written with refractive index using Glad-stone Dale relation, density
information can also be obtained. High sensitivity measurement is possible with a parallel lightobservation however, the schlieren method is difficult to measure the density quantitatively andis used for qualitative visualization as a projected two-dimensional image. We have studied the
Background Oriented Schlieren (BOS) technique which is a new visualization method
developed by Meier.[1] The BOS technique measures the displacement of the background image
caused by refractive index change as for the schlieren method. The big advantage of the BOS
is that quantitative measurement is possible with a very simple setup consist of a backgroundand a digital camera. Quantitative density measurement is achieved with image analysis of theacquired images. However, drawbacks are that the sensitivity is lower than that of the Schlieren
method and that the camera cannot focus on both the background image and the test model. In
order to overcome these drawbacks, the telecentric optical system [2] and digital projector are
introduced into BOS measurement. The parallel projection of the test model with the flow field
can be captured with this setup and the background position can be set at any position.
Experiments are carried out at suction-type supersonic wind tunnel at Chiba University toevaluate the proposed BOS setup. As a result, the experimental data were confirmed to be
proportional to the theoretical values.
REFERENCES[1] G.E.A. Meier. Computerized background-oriented schlieren. Experiments in Fluids,
Vol.33, pp181-187, 2002
[2] Masanori Ota, Friedrich Leopold, Ryusuke Noda, Kazuo Maeno. Improvement in spatial
resolution of background-oriented schlieren technique by introducing a telecentric opticalsystem and its application to supersonic flow. Exp. Fluids Vol. 56, 2015

PSFVIP13-96

STEREO-PIV MEASUREMENT OF A BI-STABLE WAKE BEHIND A SIMPLIFIEDSEDAN-TYPE VEHICLE MODEL IN A CROSSWIND*C. Hasegawa1, T. Hiraoka1, T. Nakashima1, T. Kanehira1,
H. Mutsuda1, K. Shimizu2 and Y. Nakamura2
1

Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527 Japan*m220112@hiroshima-u.ac.jp
2Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima 730-8670 Japan

ABSTRACTIn the automotive aerodynamics field, development efforts are underway to reduce
aerodynamic drag and improve driving performance. Conventionally, these performances areevaluated under yaw zero wind conditions. However, in recent years, particular attention has
been paid to aerodynamic performance in the real world, where the apparent wind directionchanges due to a natural wind on the road, another vehicle traveling around. Especially, thewind direction change sometimes causes sudden change in aerodynamic characteristics at a
certain wind direction. When such aerodynamic change occurs, each wake flow structurecausing the two aerodynamic characteristics may randomly appear around the critical winddirection. Furthermore, transient change in wind direction across the critical wind direction
cause long-time delay of the change in the wake flow structure and aerodynamic characteristics.
Then, undesirable characteristics due to a short disturbance sometimes maintain for a long time.
These phenomena make an aerodynamic performance of a vehicle worse and they must be
suppressed. In order to develop aerodynamic techniques to suppress them, it is necessary to
clarify the wake structure of the two stable states in detail.
In the present study, wake flow structures of a simplified sedan-type automobile model[1], for which bi-stability has been reported in previous studies, was experimentally clarified
by a stereoscopic PIV measurement. The bi-stable velocity distributions under the same winddirection condition were measured in a number of parallel planes, respectively. Then, by
stacking the results in their normal direction, three-dimensional wake structures in each stablestate were visualized in detail. From a comparison between the two stable wake structures, it
was shown that the main difference of flow feature regarding the sudden change in aerodynamic
characteristics was the entrainment flow from the side of the model to the base of the model. It
was also found that the increased entrainment flow caused the formation of longitudinal vortices,which may significantly increase the aerodynamic drag.
REFERENCES[1] Nakamura, Y. et al., “Identification of wake vortices in a simplified car model duringsignificant aerodynamic drag increase under crosswind conditions, Journal of
Visualization (2022), DOI: 10.1007/s12650-022-00837-8.

PSFVIP13-97

NUMERICAL ANALYSIS ON THE TEMPERATURE OF AN ETHANOL SPRAY IN
ITS MIXTURE FORMATION PROCESS UNDER DIESEL ENGINE OPERATING
CONDITIONS*H. Saitoh1 and H. Tsunoda2
1

Department of Mechanical Engineering, Sojo University, Ikeda 4-22-1, West Ward,
Kumamoto City 860-0082, Japan*saitoh@mec.sojo-u.ac.jp
2
Former Student of the Graduate School of Mechanical Engineering, Sojo University, Ikeda
4-22-1, West Ward, Kumamoto City 860-0082, Japan
ABSTRACTThis study deals with the development of controlled-ignition technology for high performance
CI (Compression Ignition) alcohol engines. Among the alcohol fuels, we focused on ethanol as
one of the promising candidates of alternative fuels. The objective of this study is to physicallyand chemically reveal the mixture formation process up to auto-ignition of an ethanol spray. In
our previous experiments and numerical analysis by using a constant volume combustion
chamber (CVCC), surrounding gas temperature and pressure conditions before fuel injection
for stable auto-ignition of an ethanol spray were revealed. As the next step, we originallydesigned and built up a rapid compression and expansion machine (RCEM) with variable
compression ratio and supply air pre-compression and heating device in order to investigate theeffect of gas flow in the combustion chamber after compression stroke on the mixture formation
process of an ethanol spray. Prior to experiments, we performed numerical analysis of fluid
flow in the intake and compression strokes of the RCEM, and we also performed the mixture
formation process of an ethanol spray in the expansion stroke. Instantaneous spatial
distributions of excess air ratio, temperature, and activated chemical species inside a spray andtheir temporal histories from fuel injection were calculated by using the commercial CFD code
“CONVERGE”. Results showed that enhancement of atomization and evaporation of ethanol
due to the fluid flow induced by the compression stroke physically obstructed temperature
increase of a spray, and endothermic reactions of H2O2 and HO2 generations chemicallyobstructed temperature increase. Generations of OH radical and H atom which are recognized
as the activated chemical species relating the chain branching reactions as auto-ignition
occurred after the H2O2 and HO2 generations. These results allow us to draw one conclusion;
Amount of heat supplied into an ethanol spray by the entrainment of high-temperaturesurrounding gas has to be superior to the above introduced physical and chemical factors oftemperature-increase-obstruction for auto-ignition. In this numerical prediction of ethanol spraymixture formation process, sufficient surrounding gas temperature for stable auto-ignition
existed between 1100K and 1200K.
REFERENCES[1] H. Saitoh, K. Uchida, N. Watanabe：Numerical Study on the Required Surrounding Gas
Conditions for Stable Auto-Ignition of an Ethanol Spray, Journal of Combustion, Volume
2019-10, Article ID 1329389, (2019), https://doi.org/10.1155/2019/1329389[2] N.M.Marinov：Detailed Chemical Kinetic Model for High Temperature Ethanol
Oxidation, International Journal of Chemical Kinetics, Lawrence Livermore National
Laboratory, p.183-220(1999)

PSFVIP13-98

MICROSCOPIC IMAGE DIAGNOSTICS WITH VISIBLE EMISSION LIGHT FOR
SELF-BURNING SURFACE TEMPERATURE DISTRIBUTION OF CFRP (CARBONFIBER REINFORCED PLASTIC) IN OXYGEN*Yojiro Ishino1 and Rion Ito1
1

Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 Japan

ABSTRACT
Carbon Fiber Reinforced Plastic(CFRP) has been widely used in variety industries because of
its high strength-density ratio. Therefore disposal method of waste CFRP should beconsidered in advance now. We have been proposed a combustion incineration of carbon
fiber(CF) residue after recycle use. However, carbon fiber residue is almost impossible to beburned out by even high temperature burnt gas because of extremely high melting point ofcarbon fiber and a low oxygen concentration in burnt gases[1].
In this study, self-sustained combustion of carbon fiber in oxygen has been reported. In orderto obtain information of the self-sustaining mechanism of the combustion, in this paper, aconvenient optical technique to acquire the 2D distribution of high surface temperature ofglowing solid material was conducted.
In this technique, magnified thermographic view of the high temperature specimen wasprovided by comparison between RGB brightness information of conventional photograph ofthe visible light emission of the surface and previously-calculated values from Planck's law
and the spectral sensitivity of the camera system.
In this paper, first, accuracy of the method was verified by comparison between the 2D
temperature distribution result of a glowing fine (0.5 mm dia.) graphite rod in burnt gas of a
propane-air premixed laminar flame and its estimated temperature distribution measured by
PR-type thermocouple and compensated by Kaskan's method. Next magnified instantaneous
2D temperature diagnostics of self-burning carbon fiber bundle in oxygen was made. The 2D
surface temperature distribution result gives very high temperature over 2900 K on carbon
fiber surface in in-oxygen combustion incineration.
Key Words: CFRP, Oxygen Combustion, 2D Measurement of Surface Temperature, Visible
Light Emission
REFERENCES[1] Ishino, Y. and Ishihara, Y., “Temperature Measurement of Self-burning CFRP(Carbon
Fiber Reinforced Plastic) in Oxygen (Image Diagnostics of High Surface Temperature
with Visible Light Emission )”(in Japanese), Proceedings of Thermal Engineering
Conferrence 2021, Japan Society of Mechanical Engineers, No.21-35, (2021), pp. 1-6.

PSFVIP13-99
NANOPARTICLES ACCUMULATION IN A PREDETERMINED POSITIONUNDER AC ELECTRIC FIELD*A. Abdelghany1, Y. Okui1, Y. Ichikawa1,2, and M. Motosuke1,2
1

Department of Mechanical Engineering, Tokyo University of Science, 6-3-1 Niijuku,
Katsushika, Tokyo 125- 8585, Japan.
*mot@rs.tus.ac.jp
2
Water Frontier Research Center, Research Institute for Science and Technology, Tokyo
University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan.
ABSTRACT
Particles accumulation under AC electric filed around electrodes embedded in a microfluidic
device is an efficient technique. However, the accumulation position and performanceoccasionally depend on the design of the electrode array and applied voltage characteristics.
For instance, on symmetric coplanar electrodes at a low-frequency range, typically < 1kHz, theinteraction between the electric field and the electric double layer generates a fluidic motion
named as AC electroosmosis (ACEO). ACEO flow is always perpendicular to the electrodeedge, driving fluid onto the electrode surface, from the gap between the electrodes across theelectrode surface [1]. Thus, using single-gap parallel symmetric coplanar electrodes, theparticles will accumulate in two different positions far from the electrodes’ gap [2].
Furthermore, enhancing the accumulation performance may require a limited design for theelectrodes such as the double-gap electrodes [3].
In this study, the use of coplanar symmetric electrodes was also able to induce a flow to the gap
between the electrodes in a high-frequency range, namely 50-100 kHz. This flow is used toaccumulate polystyrene nanoparticles (PsNPs) in a microfluidic device embedded withsymmetric coplanar electrodes. Different from previous research that used the symmetriccoplanar electrodes to accumulate particles at two different positions under low frequency [2],the symmetric coplanar electrodes microfluidic device is utilized to accumulate thenanoparticles to a predetermined single spot at high frequency. The concentration performance
was systematically studied by using particles with a size of 100 nm. In addition, the relation
between the concentration factor (CF) and voltage characteristic was also examined, and as aresult, we found that accumulation location and resultant factor were completely changed
according to applied frequency and voltages.
REFERENCES[1] Green, N.G., Ramos, A., González, A., Morgan, H. and Castellanos, A., “Fluid flow
induced by nonuniform ac electric fields in electrolytes on microelectrodes. I.
Experimental measurements.”, Physical review E, Vol. 61, No. 4 (2000), pp. 4011-4018.
[2] Islam, N. and Wu, J., “Microfluidic transport by AC electroosmosis.”, Journal of Physics:
Conference Series, Vol. 43, No. 1 (2006), pp. 356 -361.
[3] Motosuke, M., Yamasaki, K., Ishida, A., Toki, H. and Honami, S., “Improved particle
concentration by cascade AC electroosmotic flow.” Microfluidics and Nanofluidics, Vol.
14, No. 6 (2013), pp. 1021-1030.

PSFVIP13-100

RESOLUTION ENHANCEMENT BY THE EDSR METHOD FOR BOS ANALYSES*K. Ota1 and T. Ukai1
1Osaka Institute of Technology, 5-16-1 Omiya, Asahi-Ku, Osaka 535-8585 Japan*m1m21407@st.oit.ac.jp
ABSTRACT

Background Oriented Schlieren (BOS) methods are substituted for the conventional schlieren
methods for quantitative density measurements. A schlieren system requires the expensive
optical components such as concave mirror and lens, whereas the BOS method has anadvantage in that it can take images using only a digital camera, light source, and backgroundpattern, thereby allowing the measurements without the complicated optical components [1].
Additionally, the flow field can be quantitatively visualized using post processing in a BOS
analysis. The cross-correlation method, which vector resolution is reduced than an original
image resolution, is used in the most of post processing of the BOS analysis. Therefore, theenhancement of the vector resolution is necessary to visualize detailed flow structure.
important for visualizing a detailed flow field.
A super-resolution technique based on convolutional neural networks is used for resolution
enhancement. An application of the super-resolution technique for the flow field is not too
much. One of the applications is that Kong et al. used the super-resolution technique for a
supersonic flow visualized by the schlieren method [2]. Additionally, Liu et al. reproduced
the turbulent structure of a two-dimensional flow field using super-resolution technique [3].
In these typical applications, they focus generally on the enhancement of the image resolution
without post image processing. The post processing plays a key role in the BOS analysis, andthe effectiveness of the super-resolution technique for such a post processing is unknown.
In this study, we applied EDSR (Enhanced Deep Residual Networks for Single Image SuperResolution) method, which is a representative super-resolution technique, to the BOS analysis. The BOS
images and the open source images were used for training in the machine learning. We used the Bicubic
interpolation and the EDSR method to evaluate the comparison of their performances. Consequently,
the EDSR method provided a better quality of the BOS image than that of the Bicubic interpolation.
And then, we will investigate the effects of the different interrogation window sizes on the BOS image
which its resolution is enhanced by the EDSR method.

REFERENCES[1] G. Meier, “Computerized background-oriented schlieren,” Exp. Fluids 33, pp.181-187(2002).
[2] C. Kong, J. Chang, Z. Wang, Y. Li, W. Bao, “Data-driven super-resolution
reconstruction of supersonic flow field by convolutional neural networks,” AIP Adv. 11,065321 (2021).
[3] B. Liu, J. Tang, H. Huang, X.Y. Lu, “Deep learning methods for super-resolution reconstructionof turbulent flows,” Phys. Fluids 32,025105 (2020).

PSFVIP13-101

Free surface flow of concentrated particle suspension in HeleShaw cell
T. Koshiba1 and T. Yamamoto2
1

National Institute of Technology, Nara College, 22, Yatacho, Yamatokoriyama,
Nara 639-1080 Japan
koshiba@mech.nara-k.ac.jp
2
Osaka Electro-Communication University, 18-8, Hatsucho, Neyagawa,
Osaka 572-8530 Japan

ABSTRACT
Particle suspensions dispersed solid particles in liquid are seen in many fields, for example, themanufacturing of composite materials, food industry, the development of pharmaceutical, andcivil engineering, etc. In general, it is well known that the flow of particle suspension is affectedby various factors relating to dispersions and solvents. Especially, particle concentration is oneof important factors and closely relates to complex phenomena in flow. In the case ofconcentrated suspension, peculiar phenomena like a jamming and a phase transition arise frominteraction between particles. The effect of the particle interaction on flow behavior ofsuspension is interesting in the view of rheology. In this study, the particle behaviors in freesurface flow of suspension were examined experimentally. As free surface flow, we used aradial flow pattern flowing in a Hele-Shaw cell which is constructed by two parallel plates.
Furthermore, we prepared six kinds of suspension with different concentrations and particle
sizes as test fluids and observed temporal change in interface shape in flow. The suspension
flow was controlled by adjusting a supply pressure to Hele-Shaw cell. In the observation of freesurface, we found that the undulation of liquid surface with time occurred. Additionally, in theinside region of the concave and convex part on free surface, we confirmed the non-uniformityof particle concentration suggesting particle aggregation [1]. The undulation of free surface
depends on the particle concentration and the pitch of undulation becomes large with increasing
the particle concentration. Furthermore, in experiments using smaller size of particles, we foundthat the undulation of free surface transited to the viscous fingering seen in flow of two fluidswith different viscosity. In the radial flow pattern between parallel plates, since the velocity
component of the radial direction decreases with increment in interface radius, the mean shear
rate acting on fluids also decreases. Accordingly, it was considered that the non-uniformity ofparticle concentration seen in the inside of free surface suggested the hydrodynamicalinteraction between particles accompanying to the change in shear deformation.
REFERENCES[1] Luo, R., Chen, Y. and Lee S., “Particle-Induced Viscous Fingering: Review and Outolook”,
PHYSICAL REVIEW FLUIDS, Vol. 3, (2018), pp. 110502-1-110502-15.

PSFVIP13-102

SIMULTANEOUS MEASUREMENT OF GASEOUS FLOW AND SPARK CHANNELUSING INEXPENSIVE INORGANIC FLUORESCENT TRACER*C. Kondo1 and M. Yoshioka1
1

Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005 Japan*c-kondo@ous.ac.jp

ABSTRACT
Flow dynamics near the spark-plug gap and its effect on the behavior of spark dicharge andthe development of initial flame kernel have become important in promoting more stablelean/dilute combustion in internal combustion engines. One of the experimental techniques formeasuring instantaneous gaseous flow near solid objects such as a spark plug is fluorescentparticle image velocimetry (f-PIV). However, many of the available fluorescent particles are
expensive and/or combustible because they are organic materials. Then, previous our studies
have proposed mass production of inexpensive inorganic-based fluorescent particles (fparticles), and we found that such f-particles have also been used in f-PIV measurements of the
air flow around a spark-plug gap in automotive applications, and the flow even between theplug gap could be detected under atmospheric conditions [1]. In the present study, weinvestigated the possibility of simultaneous measurements of the spark channel and the flow
behind of it including even between a spark-plug gap using f-PIV with the proposed f-particles,in future in order to validate the corresponding numerical models, such as the behavior of spark
channel. As a result, under atmospheric air condition, the fluorescence images of particles wasable to be detected, separating from the spectrum of spark discharge even between the gap of
spark plug at spark timing, using combinations of the proposed f-particles and adequate opticalband-pass filters, then the flow behind of spark channel was analyzed. This measurement
technique also possibly leads to validate the models of development and extinction of initial
flame, by developing the simultaneous measurement of gaseous temperature, underinvestigation using f-particles which emit multi-color fluorescence [2].
REFERENCES[1] Kondo, C., “Fluorescent PIV measurement of gaseous flow near spark plug gap using
inexpensive inorganic fluorescent tracer”, Proc. The 29th International Symposium on
Transport Phenomena, No.58 (2018), pp.1-6.
[2] Kondo, C. and Yoshioka, M., “Production of two - color inexpensive inorganic fluorescent
tracer as an advancement toward the simultaneous measurement of gaseous flow andtemperature in engines”, Proc. The 32nd International Symposium on Transport
Phenomena, No.90 (2022), pp.1-7.

PSFVIP13-104

EFFECT OF CONTTAINER SIZE ON FLOW STRUCTURE IN A RECTANGULARCONTAINER INJECTED AIR FROM A SLIT NOZZLE*T. Ichihara1, T. Kiwata2, K. Toyoda3, H. Uchida4, Y. kawamura4 and M. Tsuji4
1

Graduate School of Natural Science and Technology, Kanazawa University
Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192, Japan*itakuto@stu.kanazawa-u.ac.jp
2
School of Mechanical Engineering, Kanazawa University
Kakuma-machi, Kanazawa-shi, Ishikawa 920-1192, Japan
3
Hokkaido University of Science,
7-Jo 15-4-1 Maeda, Teine, Sapporo, Hokkaido 006-8585, Japan
4
Universal Can Corporation, 1500 Suganuma, Oyama-cho,Sunto-gun, Shizuoka 410-1392, Japan

ABSTRACT
Plane jets have been used for drying, heating, cooling, dust removal, and many otherapplications. The jet injected from a nozzle inserted in a container is used to dry and heat on
the inside wall of the container. Shakouchi et al. [1] and Mataoui et al. [2] have shown the effects
of nozzle length and location and Reynolds number on the flow structure in a container with an
inserted rectangular nozzle. However, the effect of jets injected from outside the container has
not been examined. The present paper experimentally investigates the effect of container sizeon the flow structure in a container when air is injected from a slit nozzle installed outside thecontainer.
Air was injected into the container through a slit nozzle of 5 mm in width b0 and 300 mm
in length, which was installed at the top of the container. The Reynolds number of the jet waschanged from Re = 2,000 to 4,000 (Re = U0b/ν, where U0 is the velocity at the center of thenozzle exit and ν is the air kinematic viscosity). Three types of containers with widths of D =50, 60 and 70 mm were tested. The velocity in the container was measured by PIV for aspectratios of H/D = 1 to 3, where H is the container depth. The nozzle position was also changed
horizontally from the center of the container to the container wall.
It was found that the aspect ratio H/D of the container and the Reynolds number of the jet
had an influence on the flow structure in the container. When the H/D of the container is small,a single recirculation vortex region is generated in the whole container. When the H/D of thecontainer is large, two recirculation vortex regions are created in the container. Vortex 1 isgenerated at the upper part of the container, and vortex 2 is generated at the lower part of thecontainer and rotates the opposite direction of vortex 1. The size of vortex 1 does not change as
the depth of the container increases. However, the size of vortex 2 expanded as the depth of thecontainer increases.
REFERENCES[1] Shakouchi, T., Suematsu, Y. and Ito, T., “A Study on Oscillatory Jet in a Cavity”, Bulletinof JSME, Vol. 25, No. 206 (1982), pp.1258-1265.
[2] Mataoui, A., Schiestel, R. and Salem, A., “Flow Regimes of Interaction of a Turbulent
Plane Jet into a Rectangular Cavity: Experimental Approach and Numerical Modelling”,
Flow, Turbulence and Combustion, Vol 67, No.4 (2001), pp.267-304.

PSFVIP13-105

EVALUATION OF PRESSURE DISTRIBUTION AROUND SMALL ROTORBLADE IN LOW OXYGEN PARTIAL PRESSURE REGION USING PSP
K. Ogawa1, *Y.R. Li1, S. Someya2, T. Inagaki1, S. Saito2, S. Baba2 and N. Takada2
1

Graduate School of Sci. and Eng., Ibaraki Univ., 4-12-1 Nakanarusawa, Hitachi 316-8511
2
AIST, 1-2-1 Namiki, Tsukuba 305-8564 Japan*yanrong.li.mech@vc.ibaraki.ac.jp

ABSTRACTIn recent years, pressure distribution measurement with high accuracy by PSP (Pressure
Sensitive Paint) has been performed for high-speed moving objects with large pressure changes.
However, there remains a problem in measuring pressure around low-speed moving objects
such as small rotating machines, because the pressure sensitivity of PSP near atmosphericpressure is too small. In the present study, the effects of oxygen partial pressure on the static
properties of PSP were investigated. Sample coupon tests using a vacuum container wereconducted for PdTFPP/Poly(IBM), PtOEP/Poly(IBM), Ru(dpp)3/Poly(IBM) and Ru(dpp)3. The
oxygen partial pressure was set to be between 2 - 10 kPa (with an interval of 2 kPa) and thetotal pressure was set to be between 20 - 100 kPa (with an interval of 20 kPa). The intensities
of PSP emission, that are normalized by the maximum intensity in oxygen partial pressure = 0
kPa, i.e., the relative intensity of PSP emission, decreases with the increasing of oxygen partialpressure. Total pressure had almost no effect on the relative intensity change of tested PSP. The
relationship of the rate of change in relative intensity is Ru(dpp)3/Poly(IBM) > Ru(dpp)3 >PtOEP/Poly(IBM) > PdTFPP/Poly(IBM). Ru(dpp)3/Poly(IBM) shows the highest pressure
sensitivity, where PdTFPP/Poly(IBM) shows the lowest pressure sensitivity between the tested
PSP.

Acknowledgment
This work was supported by JSPS KAKENHI Grant Number JP20K20978.
REFERENCES[1] Taku NONOMURA, Keisuke ASAI, “Simple estimation of Frequency Response of Two-layer
Pressure sensitive pint Model”, Trans. Japan Soc. Aero. Space Sci., Vol. 62, No. 2, pp. 112–115,
2019

PSFVIP13-106

NOISE SUPPRESSION METHOD FOR PSP DATABASED ON REDUCED-ORDER MODELING*T. Inoue1, Y. Matsuda1,2, T. Ikami3,4, T. Nonomura3, Y. Egami5 and H. Nagai4
1

Department of Modern Mechanical Engineering, Waseda University, 3-4-1 Ookubo,
Shinjuku-ku, Tokyo, 169-8555, Japan* deseiko@ruri.waseda.jp
2
Japan Science and Technology Agency, PRESTO, Saitama 332-0012, Japan3
Department of Aerospace Engineering, Tohoku University, 2-1-1 Katahira, Aoba-ku,
Sendai, Miyagi-prefecture 980-8577, Japan
4
Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagiprefecture 980-8577, Japan
5
Department of Mechanical Engineering, Aichi Institute of Technology, 1247 Yachigusa,
Yakusa-Cho, Toyota, Aichi-prefecture 470-0392, Japan

ABSTRACTPSP (Pressure-Sensitive Paint) is one of the effective pressure measurement techniques. The
PSP method is based on oxygen quenching of the phosphorescence emitted from the PSP
coating, and pressure can be measured by detecting the variation of the phosphorescence usinga camera. Since the PSP images contain noticeable noise such as the camera shot noise and thereadout noise, it is important to remove the noise to detect small fluctuation of the pressure.
One of the most effective ways to remove noise is to average images taken under the same
conditions. But this method cannot be used for unsteady pressure field.
Therefore, we propose a method to remove noise from unsteady pressure field data. basedon the proper orthogonal decomposition (POD) calculated from time-series PSP data and theLASSO (Least Absolute Shrinkage and Selection Operator) regression. The noise is suppressedby truncating the lower modes of POD. To determine the coefficients for each POD mode, we
use the sensor selection algorithm and LASSO regression. We applied our method to thepressure field induced by the Kármán vortex street behind a square cylinder. As a result, theerror between the processed PSP data and the pressure tap data is greatly reduced, indicatingthat the proposed method is effective in removing the noise.

REFERENCES[1] Inoue, T., Matsuda, Y., Ikami, T., Nonomura, T., Egami, Y., Nagai, H., “Data-Driven
Approach for Noise Reduction in Pressure-Sensitive Paint Data Based on Modal
Expansion and Time-Series Data at Optimally Placed Points”, Physics of Fluids, Vol. 33(2021), 077105.
[2] Suzuki, K., Oshima, A., Hong, C. and Mochizuki, M., “Subcooled Flow Boiling in a
Minichannel”, Heat Transfer Engineering, Vol. 32, No. 7-8 (2011), pp. 667-672.
[3] Zienkiewicz, O.C. and Taylor, R.C., The finite element method, 4th Edition, Vol. I(1989), McGraw Hill.

PSFVIP13-107

SCHLIEREN VISUALIZATION OF EXTINGUISHING PROCESS OF DIFFUSION
FLAMES IN AIRBURST BLAST EXTINGUISHMENT WITH MICRO EXPLOSIVES*A. Yuma Yoshida and B. Hiroyuki Torikai
Hirosaki University, Bunkyo Town 1, Hirosaki, Aomori 036-8560 Japan*A. h22ms543@hirosaki-u.ac.jp and B.torikai@hirosaki-u.ac.jp

ABSTRACT
A blast extinguishment is one of methods to extinguish a fire, which basically consists of adiffusion flame, using a blast waves produced by detonation of explosives and a flow of gaseous
detonation products. Using the method, we can put out intense fires instantaneously and it
controls the extinguishing effective range by adjusting the amount of input energy to the
explosion. Therefore, it can be said that it is used as emergency mitigation measures for large
forest fires and post-earthquake fires. The authors have conducted experimental studies of
airburst blast extinguishment on a laboratory scale [1-3]. In airburst, the blast wave is reflectedon the ground. When the reflected blast wave merges with the incident shock wave to form asingle wave, which is known as the Mach Stem. Few studies have focused on elucidation ofrelationship between the extinguishing effectiveness of the airburst blast extinguishment andthe Mach stem.
In this study, in order to clarify the blowoff characteristics of airburst blast
extinguishment, we have conducted laboratory-scale experiments to blast off a methane-air jet
diffusion flame using 10 mg silver azide pellets. In addition, to reveal the extinguishing effectof the Mach stem, the extinguishing processes have been investigated with a schlieren
visualization method.
From the experimental results, we show the existence of the optimal height of burst for
extinguishing the jet diffusion flame. At the optimal height of burst, the Mach stem is formed
just before the incident blast wave interacts with the diffusion flame. Thus, the formation of theMach stem is considered to play an important role in airburst blast extinguishment.
REFERENCES[1] Torikai, H., “Basic research on blast extinguishment”, Journal of JAFSE “KASAI”, Vol.
67, No. 6 (2017), pp. 14-19 (in Japanese).
[2] Torikai, H., Soga, Y., and Ito, A., “Schlieren visualization of blast extinguishment withlaser-induced breakdown”, Proceedings of the Combustion Institute, Vol. 36, No. 2 (2017),
pp. 3297-3304.
[3] Sekikawa, R. and Torikai, H., “Blast extinguishment of a methane-air jet diffusion flameusing a silver azide pellet”, Science and Technology of Energetic Materials, Vol. 80, No.
1 (2019), pp. 12-14.

PSFVIP13-108
A CRYOGENIC TEMPERATURE SENSITIVE PAINT MEASUREMENT USINGMETAL COMPLEX MATERIALS AND PHOSPHORS ~PLELIMINARY
EXPERIMENTS~
S. Yasuzawa1,2, *S. Someya2, Y.R. Li1 , S. Saito2, S. Baba2 and N. Takada2
1

Graduate School of Sci. and Eng., Ibaraki Univ., 4-12-1 Nakanarusawa, Hitachi 316-8511
2
AIST, 1-2-1 Namiki, Tsukuba 305-8564 Japan* s.someya@aist.go.jp
ABSTRACT

Thermal control, an effective utilization of unused heat, is important for ensuring the efficiency
of sophisticated mechanical systems. The measurement of temperature and heat flux is
indispensable for realizing advanced thermal control. An effective use and a control of a cold
thermal energy of the liquid natural gas or the liquid hydrogen is essential for reducing
greenhouse gas emissions and for achievement of carbon neutral society. However, temperature
measurement methods applicable to such cryogenic system are limited, e.g., using an infrared
camera in a low temperature condition is difficult because of the low IR emission. A
commercial IR camera can be used at temperature over -40 degrees.
We investigated temperature sensitivity of many kinds of organic / inorganic luminescentmaterials and clarified several temperature sensitive materials. In this presentation, we show ademonstration of transient temperature measurement of a low temperature copper surface
heated by a pulsed electro-heater. The copper plate was cooled by using liquid nitrogen and its
temperature was kept at -90 degrees before the heating. Then, a part of the copper plate washeated during 10ms using a nichrome wire heater.

Acknowledgment
This work was supported by JSPS KAKENHI Grant Number JP20H02073.
REFERENCES[1] Someya, S., “Particle-based temperature measurement
measurement”, Meas. Sci. Technol. 32 (2021) 042001.

coupledwithvelocity[2] Kim, D., Kim, M. and Kim, K. C., “Effect of frost on phosphorescence for thermographic
phosphor thermometry”, Meas. Sci. Technol. 28 (2017) 125202.
[3] Egami, Y., Fey, U., Klein, C., Quest, J., Ondrus, V. and Beifuss, U., “Development of new
two-component temperature-sensitive paint (TSP) for cryogenic testing”, Meas. Sci.
Technol. 23 (2012) 115301.

PSFVIP13-109
A CRYOGENIC TEMPERATURE SENSITIVE PAINT MEASUREMENT USINGMETAL COMPLEX MATERIALS AND PHOSPHORS ~TEMPERATURESENSITIVITY OF OPTICAL PROPERTIES ~Y.R. Li1 , S. Yasuzawa1,2, *S. Someya2, S. Saito2, S. Baba2 and N. Takada2
1

Graduate School of Sci. and Eng., Ibaraki Univ., 4-12-1 Nakanarusawa, Hitachi 316-8511
2
AIST, 1-2-1 Namiki, Tsukuba 305-8564 Japan* s.someya@aist.go.jp
ABSTRACTAn effective use of a wasted cold thermal energy of the liquid natural gas or the liquid hydrogenis essential for reducing greenhouse gas emissions and for achievement of Net-zero CO2 society.
The measurement of temperature and heat flux is indispensable for realizing advanced thermal
control. However, there is no way to measure the temperature two-dimensionally at the lowtemperature. Using an infrared camera in a low temperature condition is difficult because of the
low IR emission. A commercial IR camera can be used at temperature over -40 degrees.
One of the other approaches of low temperature measurement is the temperature sensitive paintmethod, however, the information of temperature sensitive luminophore is quite limited.
Therefore, in this paper, we investigated the optical properties of various organic / inorganic
luminescent materials at low temperature conditions. The luminescent intensity, the shape ofemission spectra (color) and the luminescent lifetime at various cryogenic conditions from -190
degrees to the room temperature were evaluated by using a photomultiplier tube and aspectorometer. The temperature sensitivity of optical properties were summarized.

Acknowledgment
This work was supported by JSPS KAKENHI Grant Number JP20H02073.
REFERENCES[1] Someya, S., “Particle-based temperature measurement
measurement”, Meas. Sci. Technol. 32 (2021) 042001.

coupledwithvelocity[2] Kim, D., Kim, M. and Kim, K. C., “Effect of frost on phosphorescence for thermographic
phosphor thermometry”, Meas. Sci. Technol. 28 (2017) 125202.
[3] Egami, Y., Fey, U., Klein, C., Quest, J., Ondrus, V. and Beifuss, U., “Development of new
two-component temperature-sensitive paint (TSP) for cryogenic testing”, Meas. Sci.
Technol. 23 (2012) 115301.

PSFVIP13-110
IMPROVEMENT OF SPATIAL RESOLUTION OF HIGH-SPEED-BACKGROUNDORIENTED SCHLIEEN THROUGH ATOMOSPHERIC TURBULENCE*T. Mizukaki1, M. Kondo1, and T. Minezaki2
1

Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 Japan*mzkk@tsc.u-tokai.ac.jp
2
Tokyo University, 2-21-1, Osawa, Mitaka, Tokyo 181-0015 Japan

ABSTRACT
Background-oriented schlieren (BOS) method has been applied for flow visualization for bothin-door and out-door experiment on aerodynamic phenomena to obtain quantitative density
distribution around objects since Raffel[1] proposed in 2000. The BOS provides spatiallyintegrated information on density changes around objects as same as ordinally schlieren method.
On the other hand, one of advantages of the BOS against ordinally schlieren is less limitationof visualization area by optics because schlieren mirrors are not always needed. Therefore, the
BOS has advantage for flow visualization on real-size phenomena such as flow field around areal aircraft.
For application of the BOS for flow visualization around a real aircraft, one big problem besolved is improvement of distortion of images by atmospheric turbulence. Even one uses large
magnification image system, the atmospheric turbulence would prohibit high spatial resolution
in out-door because atmospheric turbulence must be strong near ground level.
In this paper, the authors applied adaptive optics[2] for improvement of spatial resolution ofvisualized images by the BOS. The adaptive optics includes a telescope, a Shack-Hartman
wavefront censer, and a MEMS-type deformable mirror. Laser-induced shock waves werevisualized by the BOS though turbulence generated by a heated steel plate. Obtained images
were determined its displacement from reference one with cross-correlation function.
Numerical analysis was also involved to evaluate the experimental results.
The experimental results showed that adaptive optics can provide improvement of spatial
resolution through atmospheric turbulence more than twice better than the case without it.
REFERENCES[1] Raffel, M., Richard, H., and Meier, G. E. A. "On the applicability of background oriented
optical tomography for large scale aerodynamic investigations," Experiments in Fluids Vol.
28, No. 5, 2000, pp. 477-481.
[2] Hardy, J. W. "Active optics: A new technology for the control of light," Proceedings of theIEEE Vol. 66, No. 6, 1978, pp. 651-697.

PSFVIP13-111
VISUALIZATION STUDY ON DROPLET ELECTROHYDRODYNAMIC
DEFORMATION IN COMBINED DC ELECTRIC FIELD AND SHEAR FLOW
Guanqiu Hao1, Xiangdong Liu1,2 and *Yongping Chen1,2,3
1

Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,
School of Energy and Environment, Southeast University,
Nanjing, Jiangsu 210096, PR China*ypchen@seu.edu.cn
2School of Electrical, Energy and Power Engineering, Yangzhou University,
Yangzhou, Jiangsu 225009, PR China
3
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy
Application, School of Environmental Science and Engineering, Suzhou University of
Science and Technology, Suzhou, Jiangsu 215009, P. R. China
ABSTRACT

A visualization experiment is conducted to investigate electrohydrodynamic deformation ofdroplet in combined DC electric field and shear flow. The detailed experimental data about bothtransient and steady droplet deformation parameter (D) and orientation (φd) are provided at R>Sand R<S (R: conductivity ratio; S: permittivity ratio) under different combinations of electricfield and shear flow. The internal flow characteristics of the deformed droplet are also examined
via the DPIV method. It is indicated that, owing to the competition of the extensional
component (EC) and the rotational component (RC) on the droplet from these two fields, theresponse of φd is faster than that of D when the electric field is combined with the shear flow.
Also under different competition of the EC and RC under R>S and R<S, the steady D and φdshow distinct variation. Especially, surface charge convection plays a non-ignorable role inenhancing and reducing droplet deformation for R>S and R<S, respectively. In addition, an
asymmetric vortex occurs inside the deformed droplet in the combined two filed, and its
velocity is reduced under R>S and enhanced under R<S when compared with those in the pure
shear flow. The available prediction models are demonstrated by the experimental data to
predict D, and a modified prediction model is proposed to improve the prediction accuracy ofφd.

PSFVIP13-113

DEVELOPMENT OF TEMPERATURE MEASUREMENT SYSTEM OF AIRFLOWUSING ULTRA-FINE THERMOSENSITIVE LUMISIS PHOSPHOR WIRE
*Yu Morito1, Shumpei Funatani1
1

University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan*g21tm033@yamanashi.ac.jp

ABSTRACTThe measurement of atmospheric temperature of gases is difficult due to the measurement
process, and new measurement methods are required by the industry. For the measurement of
hot water in a tank, a temperature measurement method using the two-color LIF method isknown [1].
The authors have proposed a method for simultaneous measurement of temperature andvelocity fields using the two-color LIF method and the PIV method with a single color
camera by optimizing the type and concentration ratio of fluorescent dyes [2].
The LIF method is a method to observe the fluorescence of a specific fluorophore by using alaser beam. Using this method, ultra-fine fluorescent wires coated with a temperaturedependent phosphor are placed in the measurement area and visualized by a camera tomeasure the temperature distribution of gases. The measurement system is relatively
inexpensive because the optical system is maintenance-free and the imaging system is a single
CCD camera of a common RGB type. The ultra-thin wire enables non-contact measurement
without affecting the flow field.
In the previous study, it was found that the two-wavelength spectroscopy using Rhodamine B
has a large measurement error due to the slight temperature dependence of the center
wavelength of Rhodamine B. In order to solve this problem, the temperature dependence ofRhodamine B was investigated using a luminescent material. Therefore, we evaluate thetemperature dependence of Lumisis phosphors and propose a two-color LIF airflow
temperature distribution measurement method using a wire with two types of Lumisis
phosphors, and evaluate the accuracy of the temperature measurement.
The validation results confirmed the usefulness of the temperature distribution measurement
using temperature-dependent phosphors, and the measurement error was significantly reducedby the temperature distribution measurement method using lumisis phosphors.

REFERENCES[1] Sakakibara,J. and Adrian,R.J.: Whole field measurement of temperature in water using two-colour
laser induced fluorescence, Exp.Fluids, Vol.26, (1999) pp.7-15.

[2] Funatani, S., Fujisawa, N. and Ikeda,H.: Simultaneous measurement of temperature and velocity using
two-colour LIF combined with PIV with a colour CCD camera and its appliccation to the turbulent
buoyant plume, Meas. Sci. and Tech., Vol.15, (2004) pp.983-990.

PSFVIP13-114

VISUALIZATION OF MICROBIAL TRANSPORT IN THE GUT
OF A ZEBRAFISH LARVA*Y. KIKUNAGA1, K. KIKUCHI1,2, K. NUMAYAMA-TSURUTA1 and T. ISHIKAWA1,2
1

Department of Biomedical Engineering, Tohoku University
6-6-01 Aoba, Aramaki, Aoba-ku 980-8579 Japan*kikunaga.yuta.r5@dc.tohoku.ac.jp
2
Department of Engineering, Tohoku University
6-6-01 Aoba, Aramaki, Aoba-ku 980-8579 Japan

ABSTRACT
There are more than 100 trillion gut bacteria in our guts, which are involved in the breakdown,
digestion, and absorption of food. Also, they have a significant impact on various diseases.
However, it is not clear how gut bacteria affect these diseases spatially and temporally, and noremedial measure has been found for diseases in which gut bacteria is the main cause. Zebrafish
have recently been used as an animal model for human disease because of high genetic homology
to humans. A particular advantage of zebrafish is that zebrafish larvae have transparent body,making in vivo imaging easy. Thus, they are a good model for intestinal studies. In this study,
therefore, to elucidate the relationship between intestinal flow and distribution of gut bacteria
under intestinal peristalsis, we used zebrafish larvae, and we performed visualization
measurements under chemically controlled intestinal peristalsis. To control intestinal peristalsis,
Zebrafish larvae were immersed in water dissolved with a drug that is either a peristaltic promoter
or inhibitor. Then, the fluorescent dye was orally injected into the zebrafish larva, and thespecimen was observed under a fluorescence microscope. Obtained fluorescence images wereanalyzed by a software Fiji. The frequencies of peristalsis in the posterior and anterior intestines
were measured because the temporal mechanical functions differ between the posterior andanterior intestines. The frequency of peristalsis was promoted by acetylcholine and inhibitedby atropine in both the posterior and anterior intestines. However, we observed that the effective
duration of the promoters and inhibitors differed between the posterior and anterior intestines.
This may affect the intestinal peristalsis and the distribution of the gut bacteria in a zebrafish
larva. This study could be essential for future studies on the interaction between gut bacteria
and intestinal peristalsis.
REFERENCES[1] P.J. Turnbaugh, R.E. Ley, M.A. Mahowald, V. Magrini, E.R. Mardis and J.I. Gordon, “Anobesity-associated gut microbiome with increased capacity for energy harvest”. Nature.
444, (2006), pp. 1027-1031.
[2] Q. He, L. Wang, F. Wang, and Q. Li, “Role of Gut Microbiota in a Zebrafish Model with
Chemically Induced Enterocolitis Involving Toll-Like Receptor Signaling Pathways”.
Zebrafish, Vol. 11 (2014), pp. 255-264.
[3] J. L. Cocchiaroand and J. F. Rawls, “Microgavage of Zebrafish Larvae”. J. Vis. Exp. 72,
e4434, (2013), pp. 1-12.

PSFVIP13-119

FUNDAMENTAL RESEARCH ON COMBINATION OF SOLID-LIQUID LEVELMEASUREMENT AND ELEMENTAL COMPOSITION ANALYSIS USINGULTRASOUND AND LASER* Y. CHEN1, N. SHOJI2, Z. ZHANG1, T. V. TRAN2, H. TAKAHASHI2 and H. KIKURA2
1

Tokyo Institute of Technology, School of Environment and Social Science, Department ofTransdisciplinary Science and Engineering, Nuclear Engineering Major, 2-12-1
Ookayama, Meguro-Ku, Tokyo, Japan 152-8550* chen.y.bm@m.titech.ac.jp
2
Tokyo Institute of Technology, Institute of Innovative Research, Zero Carbon Energy
Laboratory, 2-12-1 Ookayama, Meguro-Ku, Tokyo, Japan 152-8550

ABSTRACT
Since the accident at the Fukushima Daiichi Nuclear Power Plant (1F NPP) on March 11, 2011,
a decommissioning of the 1F NPP is underway. Data on fuel debris distribution and chemical
properties of fission products (FPs) in primary containment vessels (PCVs) will provide
valuable information for planning fuel debris removal and accident analysis. Conventionally,small samples are collected by a robot and transported to an analysis center for elemental
analysis. However, it takes a long time and is impractical to analyze the entire PCVs.
Meanwhile, a remote survey has been conducted using robots with optical cameras. However,
the images have a narrow field of view due to the dark environment in PCVs. [1]Therefore, this study focused on a laser induced breakdown spectroscopy (LIBS), whichenables in-situ elemental analysis, and constructed a remote LIBS system using a microchip
laser [2] to mount the system on a robot. However, the accuracy of LIBS measurement
decreases when the object’s surface is far from the laser irradiation focus, it is necessary toadjust the distance between the focus position and the object. In addition, In the removal of fueldebris, the process of adjusting the water level of the cooling water accumulated by fuel debris
and removing the exposed fuel debris with a mechanical arm is planned. According to the heightof fuel fragments, the best manipulator is different. Therefore, it is required to develop asimultaneous measurement method for the location of fuel debris and water level.
Therefore, this study aims to construct an elemental mapping system that can measure the solidliquid level while performing elemental analysis. In this paper, the constructed system is
described, and an integration experiment was conducted. Through the experiment, the element
distribution is successfully mapped based on the shape reconstruction result. The experimentresults also show that the integration between LIBS and ultrasonic measurement could improve
the focus of the LIBS system and could make the ultrasonic shape measurement more accurate.
REFERENCES[1] Tokyo Electric Power Company Holdings, Inc .:About the investigation inside the Unit 1
containment vessel, Decommissioning / Contaminated Water Countermeasure Team
Meeting 44th Secretariat Meeting, Tokyo (2017) pp.1-17.
[2] Koji, T., Ryuzo, N., Hironori, O., Takunori, T., Ikuo. W.: Recovery of the laser-induced
breakdown spectroscopy system using a ceramic microchip deteriorated by radiation for
the remote elemental analysis, Journal of Nuclear Science and Technology, Vol.57,
No.10 (2022) pp.1189-1198.

PSFVIP13-120

REMOTE LEAKAGE FLOW VISUALIZATION WITH
ARM-TYPE ROBOT AND THREE-DIMENSIONAL VECTOR UVP*N. Shoji1, T. Moriya1, Y. Chen1, H. Takahashi1 and H. Kikura1
1

Laboratory for Zero-Carbon Energy, Tokyo Institute of Technology, 1-12-1 Ookayama,
Meguro-ku, Tokyo 152-8550 Japan*shoji@us.nr.titech.ac.jp

ABSTRACTOn March 11th, 2011, the severe accident of the Fukushima Dai-ichi nuclear power plant (1F
NPP) was happened by the earth quack and the massive tsunami in Tohoku area, Japan. And
then, fuel debris was generated in the primary containment vessels (PCVs) of units 1, 2, and 3,
respectively. Fuel debris removal is necessary for the accident restoration, but contaminatedcoolant water leakage is an issue, and identification of its location is required.
Ultrasonic measurement techniques are promising as a method that can overcome theenvironment within the PCVs (darkness, high-radioactive, muddy water). Ultrasonic sound canbe used in opaque liquids and ultrasonic transducers are generally suited to high radiation levels,
as used in the decommissioning of Three Mile Island NPP (TMI-2) [1]. In our previous work,
we have suggested an idea to identify the leak locations by monitoring the coolant water flow
conditions (velocity and direction of the flow) [2] and focused on an ultrasonic velocity profiler(UVP) [3] as a flow measurement method that can be adapted to the environment in PCVs.
The UVP can measure the instantaneous velocity profile along on the ultrasonic propagation
path, and the original UVP is basically one-dimensional velocity component measurement.
However, real flow forms three-dimensional (3-D) flow and expected to be complex flow
structure due to interferences of objects inside the PCVs. Therefore, a measurement system isrequired to extend to 3-D flow measurement. In addition, the environmental within PCVs areunder high radiation. Thus, humans cannot access to directory, and a remote measurement by arobot is necessary.
The purpose of this study is development of the remote 3-D flow vector measurement system
combined with the robot. To extend the UVP to 3-D vector measurement, ultrasonic transducer
array was constructed by using four transducers, and signal processing method of vector
reconstruction was developed. As the robot, we constructed an arm-type robot, and theultrasonic transducer array was mounted on the arm tip. Moreover, this system applied to asimulated leakage flow to confirm the validity for identification of leakage point of 1F NPP.
REFERENCES[1] Beller, L. S., “Design and operation of the core topography data acquisition system for
TMI-2”, Three Mile Island Reports, GEND-INF-012 (1984).
[2] Nishiwaki, R., Hamdani, A., Takahashi, H., Endo, G., Kikura, H., “Development of a
Remote Water Leakage Localization System Combined with Phased Array UVP and
Robot”, Proceedings of 11th International Symposium on Ultrasonic Doppler Methods for
Fluid Mechanics and Fluid Engineering (ISUD11), (2018), pp. 88-91.
[3] Takeda, Y., “Development of an ultrasound velocity profile monitor”, Nuclear Engineeringand Design, Vol. 126 (1991), pp. 277-284.

PSFVIP13-121
VISUALIZATION OF FUEL DEBRIS SHAPE AND
MEASUREMENT OF WATER LEVEL USING PARAMETRIC ULTRASOUND*T.V. Tran1, H. Tanabe1, H. Takahashi1 and H. Kikura1
1

Tokyo Institute of Technology, 2-12-1, N1-7 Ookayama, Meguro-ku, Tokyo,152-8550 Japan*tran.t.ae@m.titech.ac.jp
ABSTRACT

Estimation of the position and shape of fuel debris is one of the most important missions indecommissioning the Fukushima Daiichi Nuclear Power Plant. Investigations using ultrasoundhave been considered recently due to its advantages to working in cloudy, dark, and highradiation environments of nuclear reactors. However, a limitation of the ultrasound method isthat the ultrasonic wave intensity is attenuated by the distance to the reflected objects. To
overcome this limitation, in this study, the parametric sound was applied to measure the distanceand the shape behavior of a simplified sample that simulated nuclear fuel debris. The parametricsound is characterized by higher directivity and lower attenuation; thus, it is expected tomeasure the shape of debris from longer distances. In this paper, the shape of fuel debris was
visualized by reconstructing the distance measurement data using parametric ultrasoundsignals. In addition, a new algorithm was developed to discriminate between the solid/liquidstates and measure the level of the water surrounding the debris.
REFERENCES[1] Endo G., Takahashi, H. & Kikura, H., "Challenge to investigation of fuel debris in RPV
by an advanced Super Dragon articulated robot arm (2) design and prototyping of alightweight super long reach articulated manipulator". 2020 International Conference on
Nuclear Engineering collocated with the ASME 2020 Power Conference, (2020).
[2] Takahashi, H., Shoji, N., Ito, A. and Kikura, H., "Fundamental Study on UltrasoundSensing Technology using Parametric Sound", WIT Transactions on Engineering
Sciences, Vol. 12, (2020), pp. 103-111.

PSFVIP13-122

RANGE EXTENSION ON ULTRASONIC MEASUREMENT OF BUBBLY FLOW VELOCITYPROFILE*W. Wongsaroj1, H. Takahashi2, N. Thong-un1, W. Treenuson3 and H. Kikura2
1 King Mongkut's University of Technology North Bangkok, 1518 Pracharat 1 Road, Wongsawang,Bangsue, Bangkok 10800 Thailand*wongsakorn.w@eng.kmutnb.ac.th
2 Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8550, Japan
3 Ministry of Higher Education, Science, Research and Innovation, 16 Vibhavadi Rangsit Road
Bangkok 10900, Thailand

ABSTRACTTwo-phase bubbly flow occurs in many industrial sectors, especially in the boiling water reactor (BWR).
It influences the operation of the reactor. The reactor can be operated safely if the behavior of bubbly
flow is understood clearly. Experimental work is required to clarify flow behavior. Generally, theexperiment has been executed on the channel or pipe. The bubbly flow velocity of bubble and liquid
phases is an important parameter affecting reactor safety. Hence, this parameter is necessary to beobtained accurately. The Ultrasonic Velocity Profiler (UVP) method [1] is applicable to obtain thevelocity distribution in fluid flow. It has been applied in several applications [2-3]. Then, the UVP has
been proposed for measuring bubble and liquid velocity on the bubbly flow [4]. However, in the normal
operation of BWR, the velocity value of both phases on the reactor core is about 2-3 m/s. This range ishigher than the maximum velocity (Nyquist velocity) of the UVP in case of the incident angle at 45°
degrees, in which the transmission ratio is high, has maximum sensitivity, and has no two-wave mode.
Therefore, the extension of the measurement range is a necessity. This paper presents the range extensionof the ultrasonic velocity profiler (UVP) to measure the flow velocity profile of bubbly flow beyond
Nyquist velocity level. The single transducer is utilized for the measurement. The phase separation
algorithm based on the integration of time-frequency analysis (TFA) and Doppler amplitudeclassification (DAC) collaborates with the cross-correlation function and is applied to achieve the target.
In order to confirm the ability of the proposed technique, the experiment at bubbly flow velocity beyond
Nyquist level in vertical pipe flow apparatus was conducted. The measurement result obtained was able
to guarantee the applicability of the proposed technique to extend the measurement range.
REFERENCES[1] Takeda, Y., "Velocity Profile Measurement by Ultrasonic Doppler Shift Method," International
Journal of Heat and Fluid Flow, Vol. 7 (1986), pp. 313-318.
[2] Kikura, H., Takeda, Y.and Durst, F., "Velocity Profile Measurement of the Taylor Vortex Flow of aMagnetic Fluid using the Ultrasonic Doppler Method" Experiments in Fluids, Vol. 26 (1999), pp.
208-214.
[3] Wada, S., Kikura, H., Aritomi, M., Mori, M. and Takeda, Y., " Development of Pulsed Ultrasonic
Doppler Method for Flow Rate Measurement in Power Plant ; Multilines Flow Rate Measurement on
Metal Pipe" Journal of Nuclear Science and Technology, Vol. 41 (2004), pp. 339-346.
[4] Wongsaroj, W., Hamdani, A., Thong-Un, N., Takahashi, H. and Kikura, H., "Extended Short-Time
Fourier Transform for Ultrasonic Velocity Profiler on Two-Phase Bubbly Flow Using a Single
Resonant Frequency". Applied Sciences, Vol. 9 (2019), 5

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MEASUREMENT OF MULTIPHASE FLOW IN ROTATING FIELD BYULTRASONIC VELOCITY PROFILER*Takumi KONNO1, Yoshihiko OISHI1, Hideki KAWAI1, Sho OSANAI1
1

Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido 050-8585 Japan*oishi@mmm.muroran-it.ac.jp

ABSTRACT
Taylor-Couette flow (TCF) has the most important and interesting characteristics in fluid
physics and engineering. TCF is generated from spinning inner cylinder in gap between innerand outer cylinders of concentric circle. TCF is more reliable as a mixing system than theprevious mixing methods such as a magnetic stirrer and a mechanical stirrer. In a culture
technique using a bioreactor, the commercialized stirrer is not applicable to the bioreactor
because the microorganisms are weak to the shear stress. The bioreactor by TCF is expected tobe performed in low shear flow in order to prevent physical disruption of microorganic cells.
Concentration and location of the microorganisms are required to measure for control of thecultivation accurately. This study shows the experimental results by an ultrasonic measurementin multiphase flows with the TCF with small aspect ratio [1]. In particular, we investigated threeflow fields: isolated mixing phenomenon in particle-dispersed solid-liquid two-phase flow,
W/O emulsion in droplet-dispersed liquid-liquid flow and microbial dispersion-based solidliquid two-phase flow.
The microorganisms behave like particles of poly-dispersion in TCF. Therefore, an isolated
mixing region (IMR) exists during low-Reynolds-number TCF in solid-liquid two-phase flow[2]. The flow in IMR causes a program of inhomogeneous particle-location while stirring. As
a fundamental study, we investigated the detection of concentration of particle in lowReynolds-number TCF using the echo variation caused by attenuation of ultrasonic energy. In
the droplet-dispersed liquid-liquid flow, we evaluated W/O emulsified fuels using ultrasonicmeasurement, produced 10 %, 20 %, 30 % water-vegetable oil emulsion at 300-800 rpm witha Taylor-Couette reactor [3]. We measured velocity profiles and attenuation of echo at every
100 rpm utilizing the ultrasonic Doppler method and echo intensity measurement. As a result,transitions of the velocity profiles and the echo attenuation were different in each water content
ratio. Finally, we performed UVP measurement on the flow of photosynthetic microorganisms
and found the possibility of measurement.
REFERENCES[1] Fujii, T., Oishi, Y., Kawai, H., Kikura, H., Situmorang, R.S. and Ambarita, H., “Frequency
Analysis of Chaotic Flow in Transition to Turbulence in Taylor-Couette System with Small
Aspect Ratio”, Journal of Physics: Conf. Series, Vol.801 (2017) 012063.
[2] Kato, Y., Oishi, Y., Kawai, H. and Kikura, H., “Measurement of particle concentration andlocation in Taylor-Couette flow by ultrasound echo intensity”, Proceedings of EPAM2016,(2016), pp. 174-175.
[3] Oishi, Y. Kawai, H., Sasayama, D. and Kikura, H., “Frequency Analysis of WaterVegetable Oil Emulsion Produced by Taylor-Couette System with Small Aspect Ratio
using Ultrasonic Doppler and Attenuation Method”, Proc. the 13th Int. Symp. Ultr.
Doppler Meth. Fluid Mech. Fluid Eng., (2021), pp. 90-93.

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EVOLVING ULTRASONIC VELOCITY PROFILER and eUVP
Y. TAKEDA1, E. WINDAHB2 and H. KIKURA3

3

1

Faculty of Engineering, Hokkaido University, N13W8, Sapporo, Hokkaido, 060-8628, Japan

2

Laboratory for Food Process Engineering, Dep. Health Science and Technology, ETH Zürich,
Switzerland

Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro,
Tokyo 152-8550, Japan
ABSTRACTUVP (Ultrasonic Velocity Profiler) has been established as a tool in experimental fluid mechanics as
wll as in food engineering as UVP-PD method. Since it has expanded a flow measurement capability froma simple velocity profiling to obtaining flow related characteristics of flowing media, the method is still
evolving to a wider range of flow measurement to plant controlling components. This evolution is
introduced. One of the further implications of evolution is to change the basic knowledge-gathering
methodology from point measurement in space or time to linear or areal measurement of time-dependent
velocity distribution. This is effectively identical to obtaining a solution of basic equation such as NS
equation – without solving the equation. The mind for such basic approach to the problem solution is yet
oldish and classical in general, so that it is expected that new idea must be given to new-comers or young
students and researchers. A development of eUVP (educational UVP) is an example of such effort at ETHZ
with TIT, and experience of introduction to the class lecture will be presented.
REFERENCES[1] U. Frisch & S. A. Orszag, “Turbulence: Challenges for theory and experiment”, Physics Today,
January 1990, p24.

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