JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical Study on Combustible Flow in Supersonic Flight Engines and Rocket Engines
Report Number：R17EACA01
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4402/
Responsible Representative
Nobuyuki Tsuboi,
Department of Mechanical and Control Engineering, Kyushu Institute of Technology

Contact Information
Nobuyuki Tsuboi tsuboi@mech.kyutech.ac.jp

Members
Satoshi Koduka, Maiko Iwai, Toshihiro Iwasa, Takahide Araki, Keisuke Yoshida,Nobuyuki Tsuboi, Yoshiki Nishikawa, Tomoki Uzaki, Ryuji Takahashi, Ayu Agou,
Kouhei Ozawa, Hichamnicolas Jourdaine

Abstract
Fundamental studies on nozzles and combustors for Japanese rocket engines and supersonic engines
are performed by using numerical simulations.

Reasons for using of JSS2
Academic and applicative researches on fluid dynamics and combustion mechanism, and developmentof effective numerical methods are carried out in order to develop Japanese rocket engines andsupersonic engines.

Achievements of the Year
Three-dimensional numerical simulation on a hydrogen jet and a freestream hydrogen flow under
supercritical pressures are performed to estimate the effects of pressure on mixing process. The results
show that the jet trajectory strongly depends on the momentum flux ratio, and pressure and Reynolds
number also affect the jet trajectories in Figs. 1 and 2. In addition, it was demonstrated that the cryogenic
jets pass through the higher trajectories under the transcritical pressure condition. By using these results,
we proposed a new scaling rule for the jet trajectories including the effect of supercritical condition.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Time averaged density contours near injection

Fig.2 Time averaged temperature contours near injectionJAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Presentations
1) Maiko Iwai, Keisuke Yoshida, Youhi Morii, Nobuyuki Tsuboi and A.Koichi Hayashi, "Twodimensional

Numerical

Analysis

on

Shock

Flame

InteractioninPremixed

Gasof

Hydrocarbon/Oxygen with Multi-Step Reaction Model," 26th ICDERS(International Colloquium
on the Dynamics of Explosions and Reactive Systems) , 1050, Aug. 2017.
2) Maiko Iwai, Keisuke Yoshida, Youhi Morii, Nobuyuki Tsuboi, A.Koichi Hayashi, Tetsuro Obara andShinichi Maeda, "Numerical Analysis on Shock/Flame Interaction in Hydrocarbon/Oxygen
Premixed Gas - Difference in the Propagation Types-," ISEM 2017(The 6th International
Symposium on Energetic Materials and their Applications) , O02-3, Nov. 2017.
3) Toshihiro Iwasa, Keiichiro Fujimoto, Daiki Muto, Nobuyuki Tsuboi, "Numerical Simulations ofTransverse Jet in Supersonic Crossflow toward an Understanding of Interaction Mechanism," 31st
International Symposium on Shock Waves (ISSW), SBM000350, Nagoya, Japan, July 2017.
4) Satoshi Kozuka, Daiki Muto, Hiroshi Terashima, Nobuyuki Tsuboi, "Numerical Study of Cryogenic
Hydrogen Jet in Crossflow under Supercritical Pressures," Asia-Pacific International Symposium on
Aerospace Technology, E6-2, Seoul, Korea, October 2017.
5) Ryuji Takahashi, Nobuyuki Tsuboi, Takashi Tokumasu, Shin-ichi Tsuda, "Validation of
applicability of classical mixing rule in a van der Waals type equation of state for oxygen-hydrogenmixture system", The 13th International Symposium on Experimental and Computational
Aerothermodynamics of Internal Flows, ISAIF13-S-0074, Okinawa, Japan, May, 2017.
6) Ryuji Takahashi, Nobuyuki Tsuboi, Takashi Tokumasu, Shin-ichi Tsuda, "Validation of classicalmixing rule coupled with a cubic equation of state for the thermodynamic properties in oxygenhydrogen mixture system", The Ninth JSME-KSME Thermal and Fluids Engineering Conference,
TFEC9-1422, Okinawa, Japan, October, 2017.
7) Ryuji Takahashi, Nobuyuki Tsuboi, Takashi Tokumasu, Shin-ichi Tsuda, "Validation of classicalmixing rule in van der Waals type equation of state applied to a non-ideal binary mixture fluid",
Fourteenth International Conference on Flow Dynamics, CRF-49, Miyagi, Japan, November, 2017.
8) Tomoki Uzaki, Tomoyuki Muta, Nobuyuki Tsuboi, Yusuke Maru, Kazuhisa Fujita, "A Numericaland Experimental Approaches on Aerodynamic Characteristics of Waverider with Orbiter", 31th
International Symposium on Space Technology and Science, g-21, June, 2017.
9) Yoshiki Nishikawa, Nobuyuki Tsuboi, Takashi Ito, Satoshi Nonaka "Aerodynamic Characteristics
Steady on Reusable Sounding Rocket using Numerical Calculation", 31th International Symposiumon Space Technology and Science, 2017-g-22, Ehime, Japan, May 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

72

Elapsed Time per Case

83.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.26
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,047,352.81

0.27

SORA-PP

200.550.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

133.51

0.09

/data

1,335.14

0.02

/ltmp

27,343.76

2.06

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Study of high-fidelity numerical schemes for compressible turbulent flows
Report Number：R17EACA04
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4403/
Responsible Representative
Soshi Kawai, Tohoku University, Aerospace Engineering

Contact Information
Hiroyuki Asada asada@cfd.mech.tohoku.ac.jp

Members
Hiroyuki Asada, Soshi Kawai

Abstract
This study focuses on developing numerical scheme based on discontinuous Galerkin (DG) methods
and large eddy simulation (LES) for high-fidelity compressible turbulent flow simulations around aircraft
to enhance guidelines for designing next-generation low-noise aircrafts by clarifying the details of
airframe noise generation.
http://www.cfd.mech.tohoku.ac.jp/kawai/index.html

Reasons for using of JSS2
Massively parallel computations using supercomputer is mandatory for high-fidelity aeroacoustic
simulations by DG methods and LES because of its high computational cost. DG methods are wellknown to be parallelization-friendly due to the high parallel efficiency and high execution efficiency.

Achievements of the Year
This study has developed fast high-order implicit DG methods (Asada et al., 2018, Computers&Fluids
submitted) and parallelization-friendly implicit time integration schemes for high-order DG methods(Asada and Kawai, in preparation). In this year, we have carried out LES of aeroacoustic using thedeveloped numerical schemes to assess its performances and investigate the physics of aeroacoustic.
Aeroacoustic around a single cylinder is first computed to validate the developed solver, and thenaeroacoustic around a high-lift device is simulated to demonstrate the capability for practical cases. In
the computations of the aeroacoustic around a cylinder, 4th-order accurate DG methods and developed
implicit time integration scheme are employed, and obtained solutions are compared with solutions by
the 6th-order compact difference scheme reported by Khalighi et al. (AIAA Journal, 2010). GoodJAXA Supercomputer System Annual Report April 2017-March 2018agreements with the reference data for turbulent statistics such as the mean velocities and velocity
fluctuations near the cylinder are obtained as well as for spectrums of velocity and pressure (sound) far
from the cylinder. In the simulations of aeroacoustic around the high-lift device, obtained results arecompared with experimental data and solutions by past works (Terracol and Manoha, AIAA paper, 2014),
and characteristic flow and aeroacoustic are investigated. In the instantaneous field of density gradient(see Fig. 1), we can observe characteristic flows such as the impingement of the shear layer generated at
the lower-edge of the slat, which makes the flows advecting in the slat cove and flows merging with thewake, and the laminar-to-turbulence transition on the upper-surface of the main-wing and the flap
provoked by the interaction between the boundary layer and the wake. The existence of flow separationon the flap has been reported to highly depend on the numerical and experimental conditions, while suchseparation can be seen in the present simulation. In the instantaneous field of div(rho u) expressing theacoustic field (see Fig. 2), the aeroacoustic generated by vortex shedding at the slat trailing edge, which
is well known to be dominant noise around the high-lift devices, is well simulated.
Similarly, we can expect the noise is generated at the wing trailing edge, but such noise is not soprominent in the present computation. The aeroacoustic is slightly generated at the location of laminarto-turbulence transition in our simulation because the flow is separated before the transition, which isdifferent trend with the work of Terracol and Manoha. We can also see the different trend of the
aeroacoustic generated at the flap trailing edge. This can be attributed to the existence of the flow
separation on the flap, and which is possibly derived from the size of the spanwise computational domain.
In future works, we will conduct the simulation with wider spanwise computational domain than in thepresent simulation, and the physics of aeroacoustic will be quantitatively investigated in detail.

Fig.1 Instantaneous density gradient around a high-lift device obtained by LES
with 4th-order implicit DG methods

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.2 Instantaneous div(rho u) around a high-lift device obtained by LES with 4thorder implicit DG methods

Publications
 Peer-reviewed papers
1) H. Asada, S. Kawai and K. Sawada," A quadrature simplification method for fast implicit
discontinuous Galerkin schemes", Computers&Fluids, accepted (in press).
2) H. Asada, S. Kawai, "A block Jacobi based high-order implicit discontinuous Galerkin scheme forturbulent flow simulations", transactions of JSASS, in preparation.
3) H. Asada, S. Kawai and K. Sawada, "Aerodynamics prediction of NASA common research modelusing high-order DG methods", Aerospace Technology, JSASS, 2017, 2017JSASS-D-17-00033.
 Presentations
1) H. Asada, "An attempt to extend split forms to modal discontinuous Galerkin schemes", Opening
Ceremony of the UW-TU : AOS, Poster Session on Composite Materials for Aircraft and Aero SpaceEngineering, University of Washington, Seattle, Washington, April, 2017.
2) H. Asada and S. Kawai, "A kinetic energy preserving modal discontinuous Galerkin methods", 49th
Fluid Dynamics Conference/35th Aerospace Numerical Simulation Symposium, JSASS-2017-2113A, Tokyo, Japan, June, 2017.
3) H. Asada and S. Kawai, "Aeroacoustic simulations using high-order implicit DG methods", JSASS
north conference, JSASS-2018-H041, Miyagi, Japan, March, 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

160 - 3000

Elapsed Time per Case

280.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.33
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,763,076.97

0.36

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

010.60

0.01

/data

9,776.23

0.18

/ltmp

2,170.14

0.16

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical Simulations of Fully Developed Turbulence
Report Number：R17EACA05
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4404/
Responsible Representative
Susumu Goto, Graduate School of Engineering Science, Osaka University

Contact Information
Susumu Goto goto@me.es.osaka-u.ac.jp

Members
Keita Hanajima, Susumu Goto, Ken Komoda, Jun Kanki, Yutaro Motoori

Abstract
In this project, we are revealing the universality in the statistics and dynamics of fully developed
turbulence at sufficiently high Reynolds numbers. For this purpose, we conduct direct numericalsimulations of turbulence under different boundary conditions so that we can investigate the small-scale
university of the simulated turbulence. We conducted, in this year, the simulations of a turbulent
boundary layer, turbulence in a rotating container, and turbulence in a periodic cube.

Reasons for using of JSS2
The main aim of the current study is to reveal the statistics and dynamics of fully developed turbulence.
This is one of the most important subjects in aerospace engineering, and it is deeply related to projects
in JAXA. In addition, the numerical simulations of turbulence at high Reynolds numbers require asupercomputer with sufficient memory and cores, we have considered the use of the JSS2.

Achievements of the Year
We have conducted direct numerical simulations of the turbulence in a periodic box, turbulence in aprecessing container, a turbulent boundary layer; and we have investigated, in detail, the statistics anddynamics of the simulated turbulence. This year, in particular, we have obtained interesting results on
the turbulent boundary layer. It is known that the hairpin-like vortices, which are observed (Fig. 1) inthe low-Reynolds-number turbulent boundary layer, disappear in regions at higher-Reynolds numbers.
Our numerical simulations reveal that the essential difference in the sustaining mechanics of small-scalevortices at low and high Reynolds numbers. This explains the disappearance of the hairpin-like vortices
in high-Reynolds-number turbulent boundary layers.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Hairpin-like vortices in a turbulent boundary layer at low Reynolds numbers.

Publications
 Peer-reviewed papers
1) Susumu Goto, Yuta Saito, Genta Kawahara, Hierarchy of antiparallel vortex tubes in spatiallyperiodic turbulence at high Reynolds numbers, Phys. Rev. Fluids 2 (2017) 064603.
2) Yasufumi Horimoto, Susumu Goto, Sustaining mechanism of small-scale turbulent eddies in aprecessing sphere, Phys. Rev. Fluids 2 (2017) 114603.
3) Yasufumi Horimoto, Gabriel Simonet-Davin, Atsushi Katayama, Susumu Goto, Impact of a small
ellipticity on the sustainment condition of developed turbulence in a precessing spheroid, Phys. Rev.
Fluids 3 (2018) in press.
 Oral Presentations
1) Susumu Goto, Lennaert van Veen, Statistics of Spatially-Periodic Turbulence Driven by SteadyForces (22nd May 2017, SIAM Conference on Applications of Dynamical Systems)
2) Susumu Goto, Hierarchy of vortices in turbulence at high Reynolds numbers (31st October 2017,
OIST seminar)

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

16

Elapsed Time per Case

100.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.29
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,336,396.14

0.31

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

580.61

0.40

/data

10,337.83

0.19

/ltmp

13,671.88

1.03

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Multiobjective design exploration for Aerodynamic Optimization
Report Number：R17EACA09
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4540/
Responsible Representative
Koichi Yonemoto,
Kyushu Institute of Technology, Faculty of Engineering, Department of Mechanical and Control
Engineering

Contact Information
Koichi Yonemoto yonemoto.koichi873@mail.kyutech.jp

Members
Koichi Yonemoto, Yusuke Ura, Hirotoshi Tsukamoto, Masatomo Ichige

Abstract
Kyushu Institute of Technology has been studying a fully reusable space transportation system using
winged rocket called WIRES (WInged REusable Sounding rocket). One of the objectives of this projectis to design optimized airfoil of the winged rocket using evolutionary algorithms associated withcomputational fluid dynamics.

Reasons for using of JSS2
An enormous number of airfoils should be evaluated for optimization. It will be a nontrivial problem
for a workstation at our resource. Therefore, calculation cost reduction using JSS2 is desired.

Achievements of the YearIn this fiscal year, we planned to describe the optimization algorithm and carry out the multi-objective
optimization for airfoils using JSS2 which can maintain the high angles of attack at re-entry phase andhave a good lift-to-drag ratio. However, due to the delay in development, we only made calculations
using a small scale workstations.

Publications
N/A

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

N/A

Thread Parallelization Methods

N/A

Number of Processes

1

Elapsed Time per Case

1.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.01
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

0.36

0.00

SORA-PP

0.03

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

095.37

0.07

/data

572.20

0.01

/ltmp

11,718.76

0.88

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Development and application of two-phase flow solver around moving objects
Report Number：R17EACA10
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4405/
Responsible Representative
Shun Takahashi, Tokai University

Contact Information
Shun Takahashi takahasi@tokai-u.jp

Members
Shun Takahashi

Abstract
Two-phase flows with moving objects are commonly used in practical engineering products. This study
is subject to investigate the effect of the micro particles in the exhausted gas from the rocket engine tothe strong pressure waves and the thermal conductance modification due to the water film around themenisci in the heat pipes. These multiphase flows that are important from the points of the industrial
application and the academic interest must be solved by the large scaled simulation.

Reasons for using of JSS2
The micro scaled flow is solved by Direct Numerical Simulation for the statistical analysis andmodelling to predict the macro scaled flow phenomena and applies to the design of the products. The
multiphase flow simulation like a gas-particle flow based on Cartesian mesh and immersed boundary
method, however, becomes expensive in order to capture the interaction between particles and flows.
Also, the number of the time integration becomes large due to obtain the equilibrium state of the gasparticle flows. The gas-liquid two-phase flow simulation becomes large scale due to the restriction of thetime increment from the surface tension.

Achievements of the Year
We conducted large scale numerical simulations of flow including multiple particles at low Reynolds
number and high Mach number based on immersed boundary method and Cartesian mesh. Also,
accuracy of heat transfer between sphere and fluid was confirmed by comparing with the result byboundary-fitted grid.
In addition, a numerical method to solve gas-liquid two-phase flows in heat pipes was developed andapplied to thermos-fluid phenomena in a heat pipe. A rising bubble problem was used to the validation

JAXA Supercomputer System Annual Report April 2017-March 2018of the flow solver consisting of conservative level set method.

Fig.1 Vortex structure identified by the isosurface of second invariant value of thevelocity gradient tensor around multiple particles

Fig.2 A rising bubble simulation around an obstacle by two-dimensional thermosfluid analysis.

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Peer-reviewed papers
1) Nagata, T., Nonomura, T., Takahashi, S., Mizuno, Y., and Fukuda, K, "Direct Numerical Simulationof Flow around a Heated Cooled isolated Sphere up to a Reynolds Number of 300 under Subsonicto Supersonic Conditions", International Journal of Heat and Mass Transfer, Vol. 120, pp. 284-299,
2018.
 Presentations
1) Nagata, T., Nonomura, T., Takahashi, S., Mizuno, Y., and Fukuda, K, Direct numerical simulationof flow past a sphere at a Reynolds number between 500 and 1000 in compressible flows, 56th AIAA
Aerospace Sciences Meeting, Gayload Parms, Florida. January 2018.
2) Kuribayashi, T., Hamagata, Y., Mizuno, Y., Takahashi, S., Nonomura, T., Nagata, T., and Fukuda,
K. "Investigation of Heat Transfer for a Flow around a Sphere in Cartesian Mesh by using Immersed
Boundary Method," MNTC International Symposium 2017, P123, Tokai University, Kanagawa,Japan, August, 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

289

Elapsed Time per Case

250.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.48
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

4,099,214.20

0.52

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

039.34

0.03

/data

10,375.98

0.19

/ltmp

2,075.20

0.16

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

13.67

0.59

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Construction of LES Model for High Mach-number-turbulent-multi-phase-flow
model based on DNS
Report Number：R17EACA11
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4406/
Responsible Representative
Kota Fukuda, Tokai University

Contact Information
Kota Fukuda fukuda@tokai-u.jp

Members
Kota Fukuda

Abstract
In order to construct LES model for high Mach number multi-phase turbulent flow, direct numericalsimulation (DNS) of high Mach number and low Reynolds number flow around a particle will be carriedout and construction of its data base and examination of the flow phenomena will be conducted.

Reasons for using of JSS2
In this project, direct numerical simulation (DNS) of high Mach number and low Reynolds number
flow around a particle and construction of the data base will be carried out using a boundary-fitted
coordinate system. Large scale numerical simulation is essential to construct the data base.

Achievements of the YearThe characteristics of flow around a particle at a Reynolds number between 500 and 1000 and a Mach
number between 0.8 and 2.0, such as drag coefficient, flow pattern, and Strouhal number were examined.
Furthermore, effects of temperature and rotation were also investigated.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Vortex structure identified by the isosurface of second invariant value of thevelocity gradient tensor.

Fig.2 Relationship between Reynolds number and drag coefficient.

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Peer-reviewed papers
1) Nagata, T., Nonomura, T., Takahashi, S., Mizuno, Y., and Fukuda, K, "Direct Numerical Simulationof Flow around a Heated/Cooled isolated Sphere up to a Reynolds Number of 300 under Subsonicto Supersonic Conditions," International Journal of Heat and Mass Transfer, Vol. 120, pp. 284-299,
2018.
 Presentations
1) Nagata, T., Nonomura, T., Takahashi, S., Mizuno, Y., and Fukuda, K, "Direct numerical simulationof flow past a sphere at a Reynolds number between 500 and 1000 in compressible flows," 56th
AIAA Aerospace Sciences Meeting, Gayload Parms, Florida. January 2018.
2) Kuribayashi, T., Hamagata, Y., Mizuno, Y., Takahashi, S., Nonomura, T., Nagata, T., and Fukuda,
K. "Investigation of Heat Transfer for a Flow around a Sphere in Cartesian Mesh by using Immersed
Boundary Method," MNTC International Symposium 2017, P123, Tokai University, Kanagawa,Japan, August, 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

169 - 289

Elapsed Time per Case

200.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.33
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,671,845.29

0.35

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

039.34

0.03

/data

19,683.85

0.36

/ltmp

2,075.20

0.16

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

9.97

0.43

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Computational Study on Aerodynamic Characteristics of Slender Body Configurations
Report Number：R17EACA12
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4407/
Responsible Representative
Keiichi Kitamura, Gaduate School of Engineering, Yokohama National University

Contact Information
Takuya Aogaki aogaki-takuya-rf@ynu.jp

Members
Keiichi Kitamura, Takuya Aogaki, Yuya Takagi

Abstract
We conducted numerical analysis on a slender body configuration which mimics a reusable rocket. In
this study, we acquired detailed flowfields which have not been obtained from previous experiments andrelated them with aerodynamic characteristics. We also investigated and clarified effects of aerodynamic
devices such as fins and canards on the aerodynamic characteristics.
http://www.aero.ynu.ac.jp/index_en.html

Reasons for using of JSS2
From earlier studies, it is known that our calculations require at least 10 million cells. In order to reducethe computational time of such large-scale calculations significantly, we used JSS2.

Achievements of the Year
We conducted numerical simulations on a slender body configuration which mimicked a reusablerocket. From results, we found that pitching moment coefficients changed by installing canards or finsin the vehicle (Fig.1). In addition, from visualization results, it was revealed that flowfields on the leeward
side of the vehicle are affected by such aerodynamic devices (Figs.2 and 3). As a result, we clarified therelationship between aerodynamic characteristics and flowfields.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Pitching moment coeficients

Fig.2 Q isosurface (canards, 40 degrees of AOA)JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.3 Q isosurface (fins, 40 degrees of AOA)

Publications
 Peer-reviewed papers
1) Aogaki T., Kitamura K., and Nonaka S., "Computational Study on Finned Reusable Rocket
Aerodynamics during Turnover", Transactions of the Japan Society for Aeronautical and Space
Sciences. (Accept)
 Presentations
1) Aogaki T., Kitamura K., and Nonaka S., "Computational Study on Finned Reusable Rocket
Aerodynamics during Turnover", 31st International Symposium on Space Technology and Science,
2017-o-3-04, Matsuyama, June 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

128 - 1024

Elapsed Time per Case

30.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.20
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

1,413,528.60

0.19

SORA-PP

9,364.05

0.12

SORA-LM

15,468.60

7.97

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

007.15

0.00

/data

071.53

0.00

/ltmp

1,464.84

0.11

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.62

0.03

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Studies on nonlinear vortex dynamics in the later-stage of laminar-turbulent transition incompressible boundary layers
Report Number：R17EACA13
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4408/
Responsible Representative
Kazuo Matsuura, Ehime University, Graduate School of Science and Engineering

Contact Information
Kazuo Matsuura matsuura.kazuo.mm@ehime-u.ac.jp

Members
Kazuo Matsuura

Abstract
In hypersonic transitional flows, there are many complicated factors such as density fluctuation andtemperature fluctuation due to the co-existence of the region slower than the speed of sound and theregion faster than the speed of sound inside the boundary layer. Detailed investigations into the vortex
dynamics occurring inside the boundary layers are expected. In this study, we aim to clarify the nonlinear
vortex dynamics especially in the late-stage by conducting direct numerical simulations of laminarturbulent transition in compressible boundary layers observed in hypersonic flows. Also, we develop amathematical methodology to directly introduce vortices responsible for the late stage to the boundary
layers, and its computational methods.

Reasons for using of JSS2
For the investigation of boundary layer transition of hypersonic flows, numerical simulation is a central
tool because measurement is difficult due to the existence of acoustical disturbance in a wind tunnel.
Because boundary layer transition is susceptible to disturbance, and in addition transition is hard tooccur due to strong compressibility, powerful supercomputers that enable high-accuracy large-scalecomputation are necessary to get results in a short time period.

Achievements of the Year
New results are obtained regarding vortical structures generated downstream of a protuberance place
in a boundary layer, and secondary hairpin vortices generated in a transitional boundary layer.
Regarding instability that promotes the deformation and bifurcation of a hairpin vortex, a relationshipbetween the circulation magnitude of a leg and the linear stability of a shear layer is investigated.

JAXA Supercomputer System Annual Report April 2017-March 2018

Also, a new fully-nonlinear disturbance equation is derived.
Computing it simultaneously with a DNS, both linear and nonlinear instability are investigated in a
unified manner.

Publications
 Peer-reviewed papers
1) K. Matsuura, "DNS Study on the Effect of Free-Stream Turbulence on Hairpin-Vortex Evolution,"
Proc. of the 44th National Conference on Fluid Mechanics and Fluid Power, Dec. 14-16, 2017,
Amrita University, Amritapuri Campus, Kollam, Kerala, India, pp. 1-4 (2017).
2) K. Matsuura, K. Matsui, N. Tani, "Effects of Free-Stream Turbulence on the Global Pressure
Fluctuation of Compressible Transitional Flows in a Low-Pressure Turbine Cascade," International
Journal of Numerical Methods for Heat & Fluid Flow, pp. 1-13 (2017) (accepted).
3) K. Matsuura, K. Matsui, N. Tani, T. Goto, "Compressible Transitional Boundary Layers Subjectedto Rotor-Stator Interaction in a Low-Pressure Turbine," 53rd 3AF International Conference on
Applied Aerodynamics, 26-28 March 2018, Salon de Provence, France, pp. 1-7 (2018).

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

Automatic Parallelizatio

Number of Processes

16 - 64

Elapsed Time per Case

168.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.05
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

448,337.82

0.06

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

009.54

0.01

/data

095.37

0.00

/ltmp

1,953.13

0.15

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical study of the convection structure in Venus' atmospheres
Report Number：R17EACA14
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4409/
Responsible Representative
Ko-ichiro Sugiyama, National Institute of Technology, Matsue College

Contact Information
Ko-ichiro Sugiyama sugiyama@gfd-dennou.org

Members
Ko-ichiro Sugiyama, Hiroki Ando

Abstract
Our purpose is to support the observation performed by AKATSUKI (Venus Climate Orbiter) by
developing a numerical fluid dynamics model (cloud resolving model) and providing a lot of numericalsimulation data. The motion of Venus' cloud-level convection and the propagation of gravity wave driven
by convection obtained by our numerical simulation are very useful to analysis the cloud morphology at
various altitudes and characteristics of gravity wave obtained by AKATSUKI. By comparing ournumerical simulations data and the observation data of AKATSUKI, it is expected that atmosphericstructure of Venus' cloud-level will be more clearly understood.

Reasons for using of JSS2
Supercomputer is used for developing and running our cloud resolving model. To reproduce thestructure of convective motion and gravity wave propagation, it is necessary that the resolution of themodel is set to be several tens to several hundred meters. To avoid the influence of the computationalboundary and to compare with AKATSUKI's data, horizontal region of hundreds to thousands ofkilometers is required. The numerical simulations with such high resolution and wide computational
region can be performed using supercomputer only.

Achievements of the Year
We proceed further analysis of our previously performed two-dimensional simulation and find that thealtitude at which gravity wave breaking occurs and amplitude of gravity waves are consistent with thoseobtained by the observational results of radio occultation measurements. We also start to perform anumerical simulation in order to investigate a possible three-dimensional structure of Venus' cloud-level
convection and propagation of gravity wave driven by the convection. The preliminary results show that

JAXA Supercomputer System Annual Report April 2017-March 2018

the convective motion and gravity wave propagation are obtained successfully (Fig.1, 2).

Fig.1 Horizontal cross-section of vertical velocity associated with convection at 51 km altitude.

Fig.2 Horizontal cross-section of vertical velocity associated with gravity wave at 59 km altitude.

Publications
N/A

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

128 - 1024

Elapsed Time per Case

100.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.03
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

226,607.97

0.03

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

356.71

0.25

/data

3,287.00

0.06

/ltmp

1,302.08

0.10

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Fluid-discharge coupling simulation in DBD plasma actuator
Report Number：R17EACA16
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4410/
Responsible Representative
Naofumi Ohnishi, Tohoku University

Contact Information
Naofumi Ohnishi ohnishi@rhd.mech.tohoku.ac.jp

Members
Naofumi Ohnishi, Shintaro Sato

Abstract
Dielectric-Barrier-Discharge Plasma Actuators (DBD-PAs) are novel active-flow-control devices
using electrohydrodynamic force caused by atmospheric discharge. However, the practical application of
the DBD-PA is still challenging due to the low induced flow-velocity. In order to improve the DBD-PA
performance, clarification of the discharge process is a key issue because the flow is induced through thecomplicated discharge process. In this study, the discharge-fluid coupling simulation is conducted forthe elucidation of the detailed discharge process and the proposal of the applied voltage-waveform which
is suitable for the electrohydrodynamic force generation.
http://www.rhd.mech.tohoku.ac.jp/index_en.html

Reasons for using of JSS2
The numerical simulation requires enormous computational cost because both the discharge process,which has a nanosecond time scale, and the induced-flow process, which has a millisecond time scale,should be taken into account. In addition, we solve the equation of motion of the charged particle and
the Poisson's equation for the electrical potential for every time step in the discharge simulation,requiring the supercomputer. In order to investigate the effect of the applied voltage waveform on the
discharge process and the induced-flow structure, we should conduct a parametric study of the applied
voltage waveforms by using the JSS2.

Achievements of the Year
We proposed a two-stroke cycle DBD plasma actuator, which is driven by a DC voltage combined withnanosecond pulse voltage, focusing on the cycle of the dielectric surface charge. Enhancement of theJAXA Supercomputer System Annual Report April 2017-March 2018

electrohydrodynamic force was demonstrated in our numerical simulation compared to the sinusoidal
waveform case (Fig. 1). On the one hand, the sinusoidal voltage forms four strokes depending on the
dielectric surface charge; on the other hand, the DC-biased nanosecond pulse forms two strokes. A highconstant voltage is desirable for the charged particle acceleration, and a nanosecond pulse is suitable forthe charged particle generation and neutralization of the dielectric surface charge.
The induced flow simulation was also conducted using a data map, which was created by thedischarge simulation because it is not realistic to run a simulation for tens of milliseconds by couplingflow and discharge models. Our simulation result shows that the wall jet is formed by the two-stroke
cycle operation and the blast waves are repetitively generated with the same frequency as the pulse
repetition rate due to the localized heating in the vicinity of the exposed electrode tip (Fig. 2).

Fig.1 Distributions of electron number density during the pulse superposition

Fig.2 Distribution of the induced velocity magnitude in the quiescent air when the
8-kV DC voltage combined with the 25 kHz nanosecond pulses is applied

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Peer-reviewed papers
1) S. Sato, M. Takahashi, and N. Ohnishi, 'Enhanced electrohydrodynamic force generation in a twostroke cycle dielectric-barrier-discharge plasma actuator', Applied Physics Letters 110, 194101(2017).
2) S. Sato, M. Takahashi, and N. Ohnishi, 'Computational study of body force production process andperformance improvement in dielectric-barrier-discharge plasma actuator', Transactions of theJapan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, accepted.
 Non peer-reviewed papers
1) S. Sato, M. Takahashi, and N. Ohnishi, 'Induced flow simulation with detailed discharge modelingin dielectric-barrier-discharge plasma actuator', AIAA paper 2018-1293 (2018).
 Presentations
1) S. Sato, M. Takahashi, and N. Ohnishi, 'Computational study of body force production process andperformance improvement in dielectric-barrier-discharge plasma actuator', 31st International
Symposium on Space Technology and Science, 26th International Symposium on Space Flight
Dynamics & 8th Nano-Satellite Symposium, Matsuyama, June 3-9, 2017.
2) S. Sato, M. Takahashi, and N. Ohnishi, 'Numerical analysis of discharge process and induced flowin DBD plasma actuator', Tokyo, June 28-30, 2017.
3) S. Sato, M. Takahashi, and N. Ohnishi, 'Control of dielectric surface charge toward performance
improvement in DBD plasma actuator', Saitama, September 3-6, 2017.
4) S. Sato, M. Takahashi, and N. Ohnishi, 'Numerical analysis of induced flow with discharge process
in DBD plasma actuator', Kyoto, December 12-14, 2017.
5) S. Sato, M. Takahashi, N. Ohnishi, 'Induced flow simulation with detailed discharge modeling indielectric-barrier-discharge plasma actuator', AIAA SciTech Forum, Kissimmee, Florida, January 812, 2018.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

160 - 320

Elapsed Time per Case

120.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.31
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,544,476.92

0.33

SORA-PP

3,464.08

0.04

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

195.50

0.14

/data

9,813.31

0.18

/ltmp

2,929.69

0.22

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.99

0.04

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical Study of Breakdown and Shock Wave Structures for Improvement of Flight
Performance in a Beamed-Energy Vehicle
Report Number：R17EACA17
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4411/
Responsible Representative
Masayuki Takahashi, Tohoku University

Contact Information
Masayuki Takahashi mtakahashi@rhd.mech.tohoku.ac.jp

Members
Masayuki Takahashi

Abstract
Propulsion performance of a beamed-energy vehicle is improved by reproducing breakdown physics
and shock wave propagation induced inside a rocket nozzle.

Reasons for using of JSS2
We used JSS2 because computational costs for reproducing a multi-dimensional physics of the
breakdown process and shock wave propagation inside the rocket nozzle of the beamed-energy vehicle
were increased.

Achievements of the YearA multi-dimensional breakdown structure was numerically reproduced when an external magnetic field
was applied to the inside of the rocket nozzle, which indicated that the asymmetric plasma structure was
induced because of the polarization drift. In addition, the open-front approach was proposed byequipping a butterfly valve on the nozzle front, which improved the propulsion and air-breathing
performances of the beamed-energy vehicle by removing the expansion wave propagating inside therocket nozzle.

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Peer-reviewed papers
1) M. Takahashi and N. Ohnishi, "Joule-Heating-Supported Plasma Filamentation and Branching
During Subcritical Microwave Irradiation," AIP Advances, Vol. 7, 055206, 2017.
2) M. Takahashi, "Physics of Millimeter-Wave Discharge and Its Application to Microwave Rocket,"
Journal of Plasma Fusion Research, Vol. 93, No. 10, pp. 478-483, 2017.
3) M. Takahashi and K. Komurasaki, "Discharge from a High-Intensity Millimeter Wave Beam and Its
Application to Propulsion," Advances in Physics: X, Vol. 3, Issue 1, 1417744, 2018.
4) M. Takahashi and N. Ohnishi, "Open-Front Approach a Microwave Rocket Sustained by a Resonant
Magnetic Field," Journal of Propulsion and Power (accepted).
5) M. Takahashi and N. Ohnishi, "Postural Control for Beam-Riding Flight of a Microwave Rocket
Using an External Magnetic Field," Transactions of the Japan Society for Aeronautical and Space
Sciences, Aerospace Technology Japan (accepted).
6) M. Takahashi and N. Ohnishi, "Thrust-Performance Maximization of Microwave Rocket Sustained
by Resonant Magnetic Field," Transactions of the Japan Society for Aeronautical and Space Sciences,
Aerospace Technology Japan (accepted).
7) M. Takahashi and N. Ohnishi, "Gas-Species-Dependence of Microwave Plasma Propagating under
External Magnetic Field," Journal of Applied Physics (under review).
 Non peer-reviewed papers
1) M. Takahashi and N. Ohnishi, "Numerical Modeling for Microwave Breakdown on a Beaming
Rocket Supported by an External Magnetic Field," Proceedings of 10th International Workshop ofStrong Microwaves and Terahertz Waves: Sources and Applications, A3.3, 2017.
2) M. Takahashi and N. Ohnishi, "Numerical Study for Interactions between Separation on SupersonicFlow and Laser-Induced Blast Wave," Proceedings of the 31st International Symposium on ShockWaves, SBM000130, 2017.
3) M. Takahashi and N. Ohnishi, "Two-Fluid Model Development for Magnetized Plasma Driven by
an Intense Microwave Irradiation," Proceedings of Plasma Conference 2017, 21P-98, 2017.
4) M. Takahashi, T. Kogushi and N. Ohnishi, "Fluid-Orbit Coupling Calculation for Maintaining
Stable Flight of a Laser Propulsion Vehicle," Proceedings of 3rd Symposium on SSPS, 2017.
5) M. Takahashi and N. Ohnishi, "Separation Control on an Airfoil Using Repetitive Laser
Pulses,"AIAA Paper 2018-1430, 2018.
6) M. Takahashi, M. Myokan, Francesca Gnani, Henny Bottini, A. Iwakawa, N. Ohnishi and A. Sasoh,"Separation Control Using Repetitive Laser Pulses," Proceedings of Aerodynamics Symposium, 2L4,
2018.
7) M. Takahashi, M. Myokan, Francesca Gnani, Henny Bottini, A. Iwakawa, N. Ohnishi and A. Sasoh,"Separation Flow Control Using Blast Wave Propagation Induced by Repetitive Pulse Irradiation,"
Proceedings of Symposium on Shock Waves, 080, 2018.

JAXA Supercomputer System Annual Report April 2017-March 2018

 Presentations
1) M. Takahashi and N. Ohnishi, "Numerical Modeling for Microwave Breakdown on a Beaming
Rocket Supported by an External Magnetic Field," 10th International Workshop of Strong
Microwaves and Terahertz Waves: Sources and Applications, Nizhnij Novgorod, Russia, 2017.
2) M. Takahashi, "Examination of Microwave-Driven In-Tube Accelerator (MITA)," Seminar on
Discharge Induced by High-Energy Electromagnetic Beam and Its Application, Rokkasyo Village,
2017.
3) M. Takahashi, T. Kogushi and N. Ohnishi, "Fluid-Orbit Coupling Calculation for Maintaining
Stable Flight of a Laser Propulsion Vehicle," 3rd Symposium on SSPS, Tohoku University, 2017.
4) M. Takahashi and N. Ohnishi, "Separation Control on an Airfoil Using Repetitive Laser Pulses,"2018 AIAA Aerospace Sciences Meeting, Kissimmee, Florida, 2018.
5) M. Takahashi, M. Myokan, Francesca Gnani, Henny Bottini, A. Iwakawa, N. Ohnishi and A. Sasoh,"Separation Control Using Repetitive Laser Pulses," Aerodynamics Symposium, Tendo, 2018.
6) M. Takahashi, M. Myokan, Francesca Gnani, Henny Bottini, A. Iwakawa, N. Ohnishi and A. Sasoh,"Separation Flow Control Using Blast Wave Propagation Induced by Repetitive Pulse Irradiation,"
Symposium on Shock Waves, Tohoku University, 2018.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

2 - 100

Elapsed Time per Case

50.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.11
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

869,058.46

0.12

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

476.84

0.33

/data

9,765.63

0.18

/ltmp

1,953.13

0.15

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Study on Aerodynamic Design for Mars Exploration Airplane
Report Number：R17EACA18
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4412/
Responsible Representative
Seiichiro Morizawa,Tottori university

Contact Information
Seiichiro Morizawa morizawa@mech.tottori-u.ac.jp

Members
Seiichiro Morizawa

Abstract
The discussion on the aerodynamic characteristcs for a Mars exploration airplane is conducted. The
conditon of the airplane is the low Reynolds number and high high Mach number conditions, and thedata for conventional airplanes on Earth cannot be direcrely applied to the design of a Mars airplane. So,
study with CFD of these conditions around the wing is conducted for a Mars exploration airplane.

Reasons for using of JSS2
A huge computational cost is required when three-dimensinal simulation with

CFD.

So, thecomputations with a super-computer are necessary to conduct our research because the available
memory and CPU of supercomputer like JSS2 are much larger than the workstation at our laboratory.

Achievements of the Year
Three-dimensinal Numerical simulations of NACA0002 was conducted as shown in Fig. 1. Then, theaerodynamic characteristics were evaulated. The result indicates that the monotonic increases of lift anddrag coefficents occurs (Fig. 2). Then,as the angle of attack increases, it was confirmed that thepressure drag is increased while viscous drag is decreased.

We are planning to consider the Mach

number effect of this above result and investigate the change in the aerodynamic characteristics.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Computational gridFig.2 Aerodynamic characteristics at low Reynolds condition

Publications
 Non peer-reviewed papers
1) S. Morizawa, K. Sakamoto, A. Yasuda, A. Miyazaki, H. Kawazoe, "Aileron Effect by the Elevon on
the Aerodynamic Characteristics of a Mars Exploration Airplane with a Deployable-Wing, The 2016
Asia-Pasific Internatinal Symposium on Aerospace Technology, D1-2 , Toyama, Japan, October
25-27, 2016."

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

32

Elapsed Time per Case

300.00 minutes

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.01
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

34,896.09

0.00

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

158.95

0.11

/data

3,255.21

0.06

/ltmp

651.040.05

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

The Effect of Protuberant Devices on Aerodynamic Characteristics of Slender Body
VehicleReport Number：R17EACA20
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4413/
Responsible Representative
Keiichi Kitamura, Yokohama National University
Contact Information
Toshiaki Harada harada-toshiaki-vt@ynu.jp
Members
Toshiaki Harada, Keiichi Kitamura
Abstract
It is important for rocket developments to quantitatively estimate the influence of protuberances in theflight vehicles which create asymmetry of flow around the vehicles and aerodynamic forces. Using fluid
numerical computation, it is expected that we obtain a guideline for the protuberance choice in the future
rocket development by conducting systematic and fundamental aerodynamic study on protuberance i)positions and ii) sizes allowed to arbitrary flight vehicles.
http://www.aero.ynu.ac.jp/index_en.html
Reasons for using of JSS2
This study needs expensive numerical fluid analyses around flight vehicles equipped withprotuberances. Therefore, it is unrealistic that this scale of numerical calculations be carried out 100
times with workstations in the university, requiring 2.5 million grid points. Therefore, we use JSS2 inorder to ensure larger memories and to save the cost of numerical calculations.
Achievements of the Year
The protuberance (Fig. 1) was installed on the surface of rocket (cone -cylinder). Then, by changing
its positions (1.front, 2.center of gravity, 3.aft of the rocket), we conducted numerical calculations. We
calculated at M =1.5 and angles of attack increased from 0 deg. to 20 deg. with 5 deg. intervals. According
to the results, changing the protuberance position affected supersonic aerodynamic characteristics of thevehicle, especially the roll moment, side force, and yaw moment. We found that the roll moment was
minimized when the protuberance was located at aft of the rocket because the formation of its wakevortex affected the roll moment.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Outline of the flight vehicle (Body + Nozzle)

Fig.2 Outline and position of the protuberance

Fig.3 Difference of wake vortex structures due to protuberance position[(a)front, (b) middle, (c)aft, (d) front (close-up), (e) aft (close-up)]
Publications

JAXA Supercomputer System Annual Report April 2017-March 2018

 Peer-reviewed papers
1) Toshiaki Harada, Keiichi Kitamura, Satoshi Nonaka: Roll Moment Characteristics of Supersonic
Flight Vehicle Equipped with Asymmetric Protuberance, The 31st ISTS Special Issue of Transactionof JSASS (Accepted).
 Presentations
1) Toshiaki Harada, Keiichi Kitamura, Satoshi Nonaka: The Effect on Flight Vehicle Aerodynamic
Characteristics with Protuberant Devices, 2C04, The 48th JSASS Anual Meeting, Tokyo, Japan, Apr.
2017 (in Japanese).
2) Toshiaki Harada, Keiichi Kitamura, Satoshi Nonaka: Aerodynamic Analysis on Flight Vehicle with
Protuberant Devices, 2017-e-29, 31st International Symposium on Space Technology and Science,
Ehime, Japan, Jun. 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

320

Elapsed Time per Case

6.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.02
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

190,500.20

0.03

SORA-PP

1,848.02

0.02

SORA-LM

74.93

0.04

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

007.15

0.00

/data

071.53

0.00

/ltmp

1,464.84

0.11

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.24

0.01

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Influence of Fineness Ratio on Aerodynamic Characteristics of Flight Vehicles
Report Number：R17EACA21
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4414/
Responsible Representative
Keiichi Kitamura,Yokohama National University

Contact Information
Ayano Inatomi inatomi-ayano-ng@ynu.jp

Members
Ayano Inatomi, Takuya Aogaki, Keiichi Kitamura

Abstract
In this study, we investigated details of flow field around the slender-bodied-vehicle numerically withconfigurations having different fineness ratios. Interestingly, the trend of Re=6x10^6 is totally opposite
to that observed in Re=6x10^5 at 140 degrees of AOA. It was found that the configuration where theyaw force could be suppressed in Re=6x10^5 generated the largest yaw force in Re=6x10^6. From this,it was confirmed that the configuration which increases the yaw force varies with the Reynolds number.

Reasons for using of JSS2
Because there are many cases with configurations and many grids, it is necessary to use super computerfor getting accurate results in an efficient way.

Achievements of the YearIn this study, we investigated details of flow field around the slender-bodied-vehicle numerically. The
configuration consisting of 'nose cone' and 'square aftbody' parts was employed as the baseline, and then,compared with other configurations having different fineness ratios. At an angle of attack of 50 degrees,
regardless of the Reynolds number, the magnitude relationship of the yaw force is determined by theconfiguration. On the other hand, at an angle of attack of 140 degrees, the configuration where the yaw
force can be suppressed in Re=6x10^5 generates the largest yaw force in Re=6x10^6. From these facts,
it was found that the Reynolds number affects the yaw force at an angle of attack of 140 degrees. Also, it
is interesting to see a different tendency at angle of attack of 50 degrees and 140 degrees in this way. It
was thought that short and blunt shapes could suppress yaw force and asymmetry, but it was newly
confirmed that complicated flow fields change with Reynolds number at an angle of attack of more than
90 degrees.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Model A (baseline)(AOA = 140 [degrees], Re=6x10^5)

Fig.2 Model B (half size model)(AOA = 140 [degrees], Re=6x10^5)

Fig.3 Model A (baseline)(AOA = 140 [degrees], Re=6x10^6)

Fig.4 Model B (half size model)(AOA = 140 [degrees], Re=6x10^6)

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Presentations
1) Inatomi, A., Kitamura, K., Nonaka, S., ' Numerical Analysis on Slender Body towards Reusable Rocket
Aerodynamics with Different Configurations', The 48th JSASS Annual Meeting, Sanjo Conference Hall,The University of Tokyo, Japan, Apr. 14, 2017.
2) Inatomi, A., Kitamura, K., Nonaka, S., 'Numerical Analysis on Reusable Rocket Aerodynamics with
Reduced-yaw-force Configurations', 31st ISTS, Matsuyama, Japan, Jun 3-9, 2017.

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

1024

Elapsed Time per Case

8.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.01
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

53,340.31

0.01

SORA-PP

284.390.00

SORA-LM

435.27

0.22

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

007.15

0.00

/data

071.53

0.00

/ltmp

1,464.84

0.11

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.02

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical Analysys on Transition Shock Wave Oscillation to Pulsation around ForwardFacing Concave Cavity
Report Number：R17EACA23
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4415/
Responsible Representative
Toshiharu Mizukaki, Dept. of Aeronautics and Astronautics, Tokai University

Contact Information
Toshiharu Mizukaki mizukaki@keyaki.cc.u-tokai.ac.jp

Members
Toshiharu Mizukaki, Taro Odagiri, Yusuke Higo, Akari Kato

Abstract
Around the supersonic parachute for Mars probing, drastic transformation of shock-wave oscillation
has been observed. In the worst case, the shock waves oscillation deforms the parachute to collapse. In
this research, we try to revile the mechanism of transformation of the shock waves and develop the design
methodology for oscillation-free parachute. At the first step of this research, simplified model of thesupersonic parachute is investigated to compare to experimental result.
http://www.ea.u-tokai.ac.jp/mizukaki/

Reasons for using of JSS2
To carry out the computation on flow analysis around the model used in the research subject which
include shock waves oscillation, we must solve three-dimensional unsteadycompressible flow withmicrosecond time-resolution. Therefore, we decided that three-dimensional compressible solver,
FaSTAR, which had been developed by JAXA, is one of the proper solver for our subject. To analyze
shock waves oscillation around our model in three dimensional space and with fine time resolution, morethan 10 million mesh must be needed. Farther more, parallel computing was needed to reduce
computation time because more that 10 cases were needed to calculate in this subject. All the things
described above were our motivation that we needed JSS2.

Achievements of the YearIn this year, the effects of the ratio of depth (L) of the cavity to diameter (D), L/D on the mode ofshock wave oscillation were examined. This analysis has been done to clarify density/pressure profile

JAXA Supercomputer System Annual Report April 2017-March 2018

inside the cavity which experimental method can not visualize. The comparison of density profile
between experimental result and numerical one helped us to understand mechanism of shock wave
oscillation in detail.
The values of L/D were set for 0.0, 0.2, 0.5, 1.0, and 2.0. Also, spike was installed at bottom of thecavity to generate turbulence in front of detached shock wave to compare behavior of the detached shock
wave in the case of quiet flow. Ratio of diameter (d) and outside length (l) of the spike to the cavity,
d/D,

l/D, were 0.12 and 2.5, respectively.

Typical computational domain is shown in FIg.1. The

reason for l/D = 2.5 is based on the previous paper that had reported that shock wave oscillation would
not occur under the condition l/D more than 2.0.
Computational results said that behavior of shock wave oscillation shifted from oscillation to pulsation
at L/D > 0.5 for Mach2.0, and L/D > 1.0 for Mach3.0. The results reproduced the experimental results
well. Figure 2 shows one of the numerical results.

Fig.1 Computational domain

Fig.2 Numerical result on L/D = 0.5, Mach3.0

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.3 Numerical result on L/D = 1.0, Mach3.0

Publications
 Peer-reviewed papers
1) Mizukaki, T. and Yamada, K.*Transition Behavior of Shock Waves from Oscillation to Pulsation
around a Forward-Facing Concave with Spike, AIAA (2018)

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

32

Elapsed Time per Case

15.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.01
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

25,933.40

0.00

SORA-PP

179.050.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

491.14

0.34

/data

9,908.68

0.18

/ltmp

4,882.81

0.37

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Radiative Magnetohydrodynamic Simulations of Solar Atmosphere
Report Number：R17EACA25
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4416/
Responsible Representative
Haruhisa Iijima, Institute for Space-Earth Environmental Research, Nagoya University

Contact Information
Haruhisa Iijima h.iijima@isee.nagoya-u.ac.jp

Members
Haruhisa Iijima

Abstract
We evaluated the parallel scaling of the numerical code for the simulation of the solar surface
convection, called CO-RAMENS (Convection-Oriented RAdiative Magnetohydrodynamics Extensive
Numerical Solver).

Reasons for using of JSS2
As a preparation of the large-scale simulation, we intended to evaluate the parallel efficiency of thenumerical code.

Achievements of the YearWe are planning to carry out a large-scale simulation of the solar surface convection using CORAMENS. In this fiscal year, we evaluate the weak scaling of the code. The parallel efficiency is 87.1%
in the weak scaling from 2592 cores to 5184 cores.

Publications
N/A

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

2592

Elapsed Time per Case

4.00 seconds

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.00
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

205.330.00

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

009.54

0.01

/data

095.37

0.00

/ltmp

1,953.13

0.15

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Feedback Control of Flow Separation Using DBD Plasma Actuator
Report Number：R17EACA26
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4417/
Responsible Representative
Kengo Asada, Tokyo University of Science, Department of Information and Computer Technology,
Postdoctoral Researcher

Contact Information
Kengo Asada asada@rs.tus.ac.jp

Members
Kengo Asada, Takuto Ogawa

Abstract
The project develops flow control technic by using dielectric barrier discharge (DBD) plasma actuator
to establish high efficient and robust vehicle systems such as rockets, aircrafts, and motor vehicles. We
propose and demonstrate feedback control methods to adapt unsteady flows over the vehicles through aseries of high-fidelity unsteady simulations.

Reasons for using of JSS2
The large eddy simulations (LES) which are performed in the present project require a lot ofcomputational resources, and the present LESs cannot be performed by general workstations.

Achievements of the Year
High-fidelity LESs of a NACA0015 airfoil flow controlled by a DBD plasma actuator are performed toverify effectiveness of a feedback control model which we propose and which

has been alreadyinvestigated by 2D simulations. The present feedback model (Fig. 1) drives the actuator located in thevicinity of the leading edge according to the passing of vortices above a pressure sensor (x/c = 40%) on
the upper side of the airfoil. The passing of vortices is detected by abrupt pressure decrease comparedto moving-averaged pressure value. In the present model, time range of moving average is unsteadilyvaried according to FFT analysis, which extracts the dominant cycle of the pressure coefficient, toimprove robustness of control, where the time range was fixed regardless of flow condition in the model
investigated in the last year.
Figure 2 shows the time variation of the pressure coefficient Cp (black line), the moving average of Cp(red line), and the state of actuation (blue line). The figure shows that the actuator is intermittently

JAXA Supercomputer System Annual Report April 2017-March 2018

driven depending on the pressure variation. We apply the present feedback model to other flow
conditions and confirm the effectiveness of this model on each flow condition. Figures 3 and 4 show the
instantaneous flow field of vortex structures (visualized by iso-surface of Q-criterion colored bychordwise velocity) of controlled and non-controlled cases, respectively. The figure shows that large
separation from the leading edge is suppressed in the controlled case, indicating that the present
feedback control model is effective also in three-dimensional flow field.

Fig.1 Proposed feedback control modelFig.2 Time variation of pressure coefficient Cp (black line), moving average of Cp(red line), and state of actuation (blue line).

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.3 Instantaneous flow field (baseline)

Fig.4 Instantaneous flow field (with feedback control)

Publications
 Non peer-reviewed papers
1) Takuto Ogawa, Kengo Asada, Satoshi Sekimoto, Tomoaki Tatsukawa, Kozo Fujii, "Feed-backControl of Stall Separation with DBD Plasma Actuator by Detecting Vortex Passing over an Airfoil",
AIAA SciTech 2018, 7-11 January 2018, Kissimmee, Florida, USA.
2) Takuto Ogawa, Satoshi Shimomura, Kengo Asada, Satoshi Sekimoto, Tomoaki Tatsukawa,
Hiroyuki Nishida, and Kozo Fujii, "Study on the Sensing Parameters toward Better Feed-backControl of Stall Separation with DBD Plasma Actuator", AIAA Aviation Forum 2017, Denber, 5 - 9June 2017.
3) Takuto Ogawa, Kengo Asada, Satoshi Sekimoto, Tomoaki Tatsukawa, and Kozo Fujii, "LES of
Feedback Flow Separation Control by DBD Plasma Actuator over an NACA0015 AirfoilInvestigation of the Control Strategy with Pressure on the Airfoil Surface-," Katsushika, Tokyo, 30
August - 1 September 2017.

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

Automatic Parallelizatio

Number of Processes

76

Elapsed Time per Case

50.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.32
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,653,685.13

0.34

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

057.22

0.04

/data

11,098.95

0.21

/ltmp

3,906.25

0.29

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

High Resolution N-body Simulation of Planet Accretion: Effect of Fragmentation onto
Planetesimal Accretion
Report Number：R17EACA27
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4418/
Responsible Representative
Junko Kominami, Tokyo Institute of Technology

Contact Information
Junko Kominami kominami@mail.jmlab.jp

Members
Junko Kominami

Abstract
When the Sun was formed, protoplanatary disk was formed.

It is widely accepted that planets areformed through the coagulation of dust component in the protoplanetary disk. However, the Jovian
planets and icy planets were formed can not be explained using classical planet formation. For example,
protoplanets are thought to fall into the central star before they grow to the size of the Earth.
Our group are carrying out N-body simulation to investigate the planet formation process.
In this study, we use the code called "Kninja" which is adopted to JSS2 system, including gas drag, typeI migration and collisional fragmentation.
The aim of the study in this fiscal year is to see how the planet formation stage changes if the above
effects are included.

Reasons for using of JSS2
Originally, Kninja was developed on K-computer.

However, in order to obtain enough scientificresults, the computational time was not enough.
In addition, SORA-MA of JSS2 system has higher performance.

Achievements of the YearIn the past N-body simulations, when the collision takes place, two colliding bodies merge and form
one new body (perfect accretion assumption). This treatment has been incorporated not to increase
the number of bodies. Increase of the bodies leads to long simulation time. If perfect accretion isassumed, as the planetesimals grow, the number of the bodies decreases. This assumption let us able

JAXA Supercomputer System Annual Report April 2017-March 2018

to set the initial number of the bodies to be large. However, fragments affects the protoplanet's andplanetesimals' random velocity due to their dynamical friction, and have significant effect onto the planetaccretion stage. Hence, it is crucial to include the effect of fragmentation into the N-body simulation.
When the fragmentation is included in the simulation, large number off small fragments are produced.
The gas drag damps the random velocity of the fragments or small planetesimals.

Such small

planetesimals with small random velocity may enhance the planetesimal driven migration (PDM). This
PDM can carry the protoplanet toward the outer region of the disk.

In such case, inward type-I

migration may be overcome.
In our study, the gas drag, type-I migration and fragmentation are included in our large scale N-bodysimulation. By doing so, we investigated the migration of the protoplanet was surrounded by small
planetesimals with small random velocity.

These small planetesimals helped the protoplanet moveoutward (due to PDM) in the disk more smoothly than in the cases only with large planetesimals.

Fig.1 Time evolution of the protoplanet's semimajor axis. When the
fragmentation is considered, the outward migration continues.

JAXA Supercomputer System Annual Report April 2017-March 2018

Publications
 Presentations
1) Junko Kominami, "High resolution global N-body simulation of planet formation withfragmentation", JpGU, Makuhari2) Junko Kominami, "Formation of planets using large scale N-body simulations", Post K computer
Embryotic Research WS
3) Junko Kominami, "Clarifying the planet formation process with simulations",

Frontier of

Astronomy WS
4) Junko Kominami, "High resolution global N-body simulation of planet formation withfragmentation", Japan Astronomical Society
 URLs for the Research Results on the Web1) http://www.hpci-office.jp/pages/k-san_cu18

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

2 - 32Elapsed Time per Case

96.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.19
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

1,587,491.68

0.21

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

004.77

0.00

/data

047.68

0.00

/ltmp

976.560.07

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Magnetohydrodynamic simulations of space plasma processes
Report Number：R17EACA28
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4419/
Responsible Representative
Seiji Zenitani, Research Institute for Sustainable Humanosphere, Kyoto University

Contact Information
Seiji Zenitani zenitani@rish.kyoto-u.ac.jp

Members
Seiji Zenitani, Takahiro Miyoshi, Iku Shinohara

Abstract
This project investigates basic processes in space plasmas, by using supercomputer simulations. In
particular, we study "magnetic reconnection" in space, an abrupt change in magnetic topology. In orderto support research activities by ourselves and by other groups, we develop massively-parallel simulation
codes. They are publicly available on the Internet.
http://th.nao.ac.jp/MEMBER/zenitani/openmhd-e.html

Reasons for using of JSS2
Space plasma processes are basically described by magnetohydrodynamics (MHD) equations, which
are notoriously complex. Supercomputer simulation is necessary to predict the nonlinear evolution of
the system.

Achievements of the Year
We have studied basic properties of plasmoid-dominated turbulent reconnection by carrying out aseries of large-scale magnetohydrodynamic (MHD) simulations. We found that the average energy
consumption rate of the turbulent state is described by a simple scaling theory. Related to this topic, we
evaluated the influence of the numerical resolution in transition from quiet laminar reconnection toturbulent reconnection in our collaboration paper [1].
We have been improving our MHD code. For example, the 2018 version of our code employs MPI
nonblocking communication, and it runs faster than the previous versions as shown in Fig. 1. As a future
option, we have also implemented a new communication code, based on MPI-3 shared-memorycommunication.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Benchmark results of our MHD code on several systems

Publications
 Peer-reviewed papers
1) T. Shimizu, K. Kondoh, & S. Zenitani, "Numerical MHD study for plasmoid instability in uniform
resistivity", Physics of Plasmas, 24, 112117 (2017)

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

40 - 2000

Elapsed Time per Case

36.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.04
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

309,513.20

0.04

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

109.67

0.08

/data

2,096.18

0.04

/ltmp

3,320.31

0.25

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Three-dimensional turbulent magnetic reconnection
Report Number：R17EACA29
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4420/
Responsible Representative
Shuoyang Wang, The University of Tokyo

Contact Information
Shuoyang Wang yokoyama.t@eps.s.u-tokyo.ac.jp

Members
Shuoyang Wang, Takaaki Yokoyama

Abstract
Magnetic reconnection is one of the most important basic processes in plasma physics. It helps building
up models for various astronomical events. Most of these events have large system size, while thediffusion region where reconnection literally happens is small due to weak diffusivity of the astronomical
environment. Therefore, big simulations which integrate large system size with small diffusion region isrequired to approach the realistic circumstance.

Reasons for using of JSS2
The simulation of magnetic reconnection solves the big system size as well as the small diffusion
region size. It requires the usage of huge core numbers and memory, which are supplied by JSS2.

Achievements of the YearThe calculation has not finished yet. Therefore, no result can be shown.

Publications
N/A

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

64 - 2048

Elapsed Time per Case

40.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.02
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

115,457.40

0.02

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

481.61

0.33

/data

9,813.31

0.18

/ltmp

2,929.69

0.22

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Role of the Effective Prandtl Number on the Solar Convective Amplitude andStratification, and Angular Momentum Transport
Report Number：R17EACA30
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4421/
Responsible Representative
Yuto Bekki, The University of Tokyo

Contact Information
Yuto Bekki bekki@mps.mpg.deMembers
Yuto Bekki, Takaaki Yokoyama, Hideyuki Hotta

Abstract
We have investigated a possible physical process to alleviate the huge discrepancy of the large-scalesolar convective velocity between numerical simulations and local helioseismic observations (convective
conundrum). It was shown for the first time that, if the solar convection is essentially magnetized andoperates in an effectively high Prandtl number regime, the low wavenumber convective power can be
efficiently suppressed owing to the enhanced subadiabatic layer in the deep convection zone. On theother hand, it was also found that the high-Prandtl number convection tends to transport the angularmomentum radially inward, leading to a differential rotation inconsistent with observations. This study
strongly suggests that the problems of convective heat transport and the angular momentum transportconsists two sides of the same coin and must be solved integratedly.

Reasons for using of JSS2
Large-scale convection simulations covering several tens of deep density scale heights were required toinvestigate the behavior of the low wavenumber convective power.

Achievements of the YearTo begin, we have developed a new numerical simulation code from scratch to solve the fullycompressible thermal convection in a three-dimensional cartesian box.
After the validity of the numerical code was verified, several sets of large-scale convection simulations
were conducted using JAXA/JSS2 (Figure.1, Movie. 1).
It is shown that, in an effectively high-Prandtl number regime, the thermal convection is dominated bystrong downflow plumes that can transport heat in a highly non-local manner. As a result, a

JAXA Supercomputer System Annual Report April 2017-March 2018

subadiabatic (convectively-stable) layer formed near the base owing to the continuous deposition of low
entropy meterials is enhanced and extended vertically upward.

Fig.1 Entropy structure of the high-Prandtl number thermal convection. The
subsurface horizontal cut is shown at the bottom layer.

Fig.2 Upper panels: vertical velocity at (a) the surface, (b) middle convection zone,and (c) base. Lower panel: vertical cut of the entropy.
Publications

JAXA Supercomputer System Annual Report April 2017-March 2018

 Peer-reviewed papers
1) Y. Bekki, H. Hotta, and T. Yokoyama., "Convective velocity suppression via the enhancement of thesubadiabatic layer: Role of the effective Prandtl number", The Astrophysical Journal, 851;74 (2017)
 Oral Presentations
1) Y. Bekki, H. Hotta, and T. Yokoyama., "Effects of the enhanced subadiabatic layer in effectively
high-Prandtl number thermal convection", AAS 48th SPD Meeting, Portland, OR, USA. (2017. 8.
25).
2) Y. Bekki, H. Hotta, and T. Yokoyama., "Effects of Prandtl number on stratified thermal convection
with and without rotation", Helicity Thinkshop 3, Tokyo, Japan. (2017. 11. 21).
 Poster Presentation
1) Y. Bekki, H. Hotta, and T. Yokoyama., "Deep convective amplitude and stratification in an
effectively high-Prandtl number thermal convection", IAU Symposium 340, Jaipur, India. (2018. 2.
19-24).

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

N/A

Number of Processes

256 - 1024

Elapsed Time per Case

120.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.05
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

335,961.12

0.04

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

100.14

0.07

/data

5,769.73

0.11

/ltmp

2,929.69

0.22

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Study of compressible thermal turbulent boundary layer
Report Number：R17EACA31
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4422/
Responsible Representative
Soshi Kawai, Department of Aerospace Enginerring, Tohoku University

Contact Information
Kosuke Totani totani@cfd.mech.tohoku.ac.jp

Members
Soshi Kawai, Kosuke Totani

Abstract
The aim of this study is to numerically investigate the physics of compressible thermal turbulent
boundary layer, and direct numerical simulations (DNS) are performed. The understanding from the
DNS analysis will be utilized for building a wall model of large-eddy simulation for high Reynolds number
flows.

Reasons for using of JSS2
High-fidelity simulations of compressible turbulent flow need huge computational cost. Consequently,
massively parallel computations with a supercomputer are required.

Achievements of the YearA wall heat flux is one of the most important design parameters for thermal fluid devices. However, thephysics of compressible thermal turbulent boundary layer hasn't been investigated in detail. A Wall
Modeled LES (WMLES) is an effective approach for a real scale unsteady flow simulation. However thepredictive capability of WMLES hasn't been validated on thermal flow fields.
For a numerical analysis of a wall-bounded compressible turbulent boundary layer with strong wall heat
fluxes, we firstly simulated an adiabatic-wall boundary layer. The DNS code has been verified against areference of turbulent boundary layer flow (Fig. 1, 2). In addition, we developed a high-order-accurate
physically-consistent kinetic energy conservation scheme on curvilinear grids, based on the approach of
Kuya and Kawai (2018). Next year we intend to simulate isothermal-wall boundary layers using thescheme.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.1 Density-scaled turbulence fluctuations in inner scaling.

Fig.2 Density-scaled turbulence fluctuations in outer scaling.

Publications
N/A

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

384 - 512

Elapsed Time per Case

210.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.09
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA733,046.84

0.10

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

005.83

0.00

/data

4,893.41

0.09

/ltmp

1,193.58

0.09

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Requirement analysis for LiteBIRD's optical system
Report Number：R17EACA34
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4423/
Responsible Representative
Ryo Nagata, High Energy Accelerator Research Organization (KEK)

Contact Information
Ryo Nagata rnagata@post.kek.jp

Members
Ryo Nagata

Abstract
Primordial gravitational wave background is generically predicted by cosmic inflation theories. Its
amplitude indicates the energy scale of cosmic inflation. LiteBIRD maps the polarization of microwave
background sky to detect the signal of the gravitational waves. Since the signal of gravitational wave
origin (B-mode pol.) is expected to be much weaker than that of primordial density fluctuation origin
which has been already observed, it is essentially important to identify and mitigate systematic errors.
Radiation in-flow through beam far sidelobes is one of the largest contaminants which potentiallygives major impacts on Galactic foreground separation. By performing full beam convolution simulations,
we quantitatively discuss about systematic errors from such beam imperfection.
http://litebird.jp/eng/

Reasons for using of JSS2
Since LiteBIRD will achieve scan observations for full sky polarization mapping, the beam convolution
is repeated at the frequency of about 20Hz (and for the period of one year). The beam functions, which
are based on physical optics calculations (by use of GRASP), spread through almost the entire sky witharcminute resolution. For every sampling, integrands are evaluated on O(10^6) grid points. The
integrations with incessant coordinate transformations require a high performance computing resource.

Achievements of the Year
Our simulation suite consists of computation of scan, beam convolution, and map making. We
performed the simulations by assuming a 100GHz frequency band, where the microwave backgroundpolarization is relatively intense, and a 40GHz

frequency band, where Galactic synchrotron radiation

JAXA Supercomputer System Annual Report April 2017-March 2018

is dominant. The contamination leaked from Galactic plane through beam sidelobes was evaluated as afunction of locations on a beam map.
(Fig.1) shows the beam function used for the 100GHz case which is plotted against the angulardistance from the peak location. The sidelobe amplitude rapidly falls down to -50dB by 0.2 radian beyond
which it gently reduces. By using the beam pattern and a 100GHz foreground sky model, we obtained
the simulation result (angular power spectrum) shown in (Fig.2). The power of the contamination leaked
through sidelobes beyond 0.2 radian is about 10% of the lensing B-mode level (dashed curve). This issuggesting the possibility of severe biasing to the signal detection of primordial gravitational waves.
(Fig.3) shows the beam function used for the 40GHz case and (Fig.4) is the simulation result by useof the beam pattern and a 40GHz foreground sky model. The contamination level is larger than that in
the 100GHz case, because Galactic synchrotron radiation in the band is much more intense than the
microwave background polarization and also the sidelobe amplitude of the 40GHz beam pattern is larger
than that in the 100GHz beam pattern. Since an assumed detector pixel is located at an edge of
LiteBIRD's focal plane, the beam pattern has anisotropic structures one of which exhibits a large bumpat 0.2~0.4 radian from the beam peak. However, it was found to have no major contribution to thecontamination.
The far sidelobe requirement for LIteBIRD's optical system is that it shall be calibrated at the precisionlevel of -60dB. To confirm the robustness of our conclusion, we also performed simulations with higher
angular resolution for checking numerical convergence and simulations with foreground maps masked
in advance for identification of the contaminant.

Fig.1 100GHz beam pattern calculated by GRASP simulation : Hiroaki Imada (ISAS/JAXA)JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.2 Angular power spectrum of 100GHz foreground contamination leaked through beam sidelobes

Fig.3 40GHz beam pattern calculated by GRASP simulation : Hiroaki Imada (ISAS/JAXA)JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.4 Angular power spectrum of 40GHz foreground contamination leaked through beam sidelobes

Publications
 Presentations
1) Ryo Nagata, "On the systematic effects of LiteBIRD observation X", Astronomical Society of Japan2017 autumn annual meeting
2) Ryo Nagata, "On the systematic effects of LiteBIRD observation XI", Astronomical Society of Japan2018 spring annual meeting
 URLs for the Research Results on the Web1) http://litebird.jp/eng/

JAXA Supercomputer System Annual Report April 2017-March 2018

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

32

Elapsed Time per Case

2.50 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.25
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,045,870.27

0.27

SORA-PP

18.72

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

009.54

0.01

/data

1,907.35

0.04

/ltmp

1,953.13

0.15

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year

JAXA Supercomputer System Annual Report April 2017-March 2018

Numerical investigation of combustible flows using the adaptive mesh refinement (AMR)
Report Number：R17EACA35
Subject Category：JSS2 Inter-University Research
URL：https://www.jss.jaxa.jp/ar/e2017/4424/
Responsible Representative
Edyta Dzieminska, Department of Engineering and Applied Sciences, Faculty of Science andTechnology, Sophia University

Contact Information
Edyta Dzieminska Edyta.d@sophia.ac.jp

Members
Edyta Dzieminska, Yuta Aishima, Kota Sato, Yuto Hara, Mitsuharu Morishita, Hajime Sakai,
Yuichi Niga, Syota Yamamoto, Xinmeng Tang

Abstract
We mainly do the investigations the behaviors of combustible flows, especially H2/Air and H2/O2
mixtures with high or normal pressures. The interested physical phenomena include the jet flame,hydrogen safety, deflagration to detonation transition (DDT) as well as detonation.
Now well-designed adaptive mesh refinement (AMR) codes for the simulation of combustible flows arebeing perfected and are used to calculate the hydrogen jet flame and the DDT process. Fundamental
mechanism like the gradient mechanism on the onset of detonation in the DDT process will be discussed
in details owing to the high resolution by AMR. Engineering Parameters like the how fast/how widehydrogen would spread can also be analysed as well as the combustible characteristic.

Reasons for using of JSS2
Numerical calculations are used to simulate the combustible flows with AMR which provides local highresolutions. In order to discuss the detailed flame and detonation structures, the flame or detonation
fields need to be reproduced by the simulation in 2D or 3D to some extent both in time and space, which
are large-scale calculations. Therefore, the supercomputer would be necessary for use to perform such a
research. Without it, we cannot get valid data to analyse.

Achievements of the Year
1) AMR program with reaction models is perfected further.
2) Calculated Jet has developed to a penetration distance which is large enough to analyse the jet
properties and to start jet flames.

JAXA Supercomputer System Annual Report April 2017-March 2018

3) Deflagration to detonation transition (DDT) was reproduced in a tube filled with H2/O2 with highresolutions and the fundamental mechanisms of DDT and detonation have been discussed.
4) Four Peer-reviewed papers are composed based on the above results.

Fig.1 Instantaneous concentrations of hydrogen with jet pressures of 82 MPa on the yz-slice.
Black lines present the block boundaries of sketchy AMR meshes. For easier post process,the number of AMR blocks is reduced to 1/4 of that of the full AMR blocks in ac

Fig.2 A spark in the hydrogen jet with a certain location and energy.

JAXA Supercomputer System Annual Report April 2017-March 2018

Fig.3 Onset of detonation illustrated by the history of density gradient in a tube
filled with H2-O2. The spontaneous reaction wave spreads and produces
expanded products which results in a surrounding shock wave. Zeldovich
gradient mechanism for DDT can be c

Publications
 Peer-reviewed papers
1) Xinmeng Tang, Edyta Dzieminska, Makoto Asahara, A. Koichi Hayashi and Nobuyuki Tsuboi.
Numerical investigation of a high pressure hydrogen jet of 82 MPa with adaptive mesh refinement:
concentration and velocity distributions. International Journal of Hydrogen Energy 2018
(Accepted).
2) Xinmeng Tang, Edyta Dzieminska, Makoto Asahara, A. Koichi Hayashi and Nobuyuki Tsuboi.
Gradient mechanism on the onset of detonation in the deflagration to detonation transition.
Submitted to Proceedings of combustion institude as PROCI-S-17-02072.
3) Xinmeng Tang, Edyta Dzieminska, A. Koichi Hayashi, Nobuyuki Tsuboi and Makoto Asahara.
Numerical simulation of the auto-ignition and DDT by AMR. Archivum Combustionis 2018
(Resived).
4) Xinmeng Tang, Edyta Dzieminska, Makoto Asahara, A. Koichi Hayashi and Nobuyuki Tsuboi.
Investigations of 105 MPa hydrogen jets. To be submitted to Science and Technology of Energetic
Materials.

JAXA Supercomputer System Annual Report April 2017-March 2018

 Presentations
1) Hayashi Koichi et al. The simulation of high pressure jet flame from a small nozzle. 55th combustion
symposium , Toyama, 2017.

Usage of JSS2
 Computational Information
Parallelization Methods

MPI

Thread Parallelization Methods

Automatic Parallelizatio

Number of Processes

256 - 2560

Elapsed Time per Case

100.00 hours

 Resources Used
Fraction of Usage in Total Resources*1 (%): 0.12
Details
Computing Resources
System Name

Amount of Core Time (core x hours)

Fraction of Usage*2 (%)

SORA-MA

1,003,703.34

0.13

SORA-PP

0.00

0.00

SORA-LM

0.00

0.00

SORA-TPP

0.00

0.00

File System Resources
File System Name

Storage assigned(GiB)

Fraction of Usage*2 (%)/home

052.45

0.04

/data

524.52

0.01

/ltmp

10,742.19

0.81

Archiver Resources
Archiver System Name

Storage used(TiB)

Fraction of Usage*2 (%)

J-SPACE

0.00

0.00

*1 Fraction of Usage in Total Resources: Weighted average of three resource types (computing, file system,
and archiver)*2 Fraction of Usage: Percentage of usage relative to each resource used in one year