JAXA Aeronautics Magazine
Institute of
Aeronautical
Technology

2014
Shaping Dreams for Future Skies

No.5/6www.aero.jaxa.jp

Feature Stories
Aeronautical Science and Basic Technology Research
Cultivating and growing Japan’s aerospace technology
Round Table Discussion“The Future Opened Up by Unmanned Aircraft”

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5/6

2 0 14 S
UMMER No.
2014
No.

5

This issue features “Aeronautical Science and Basic Technology Research”
今号は、未来に向けた新しい技術を創り出す
which creates new technologies for the future; and Unmanned Aircraft,
基礎的・基盤的技術の研究を紹介します。
a topic that has been attracting attention in recent years.
表紙画像は、
フラップやスラットなど、航空機の高揚力装置の設計技術向上に向けた風洞試験の様子です。
The
cover
depictsa wind tunnel experiment aimed風を送って紫外線を当てる
at improving aerodynamic design
technology of high-lift devices onこaircraft,as flaps and slats.
模型の表面に蛍光塗料を混ぜたオイルを塗り、ことで機体表面の流れの様子を知るとができsuchます。
By coating the surface of a model with oil mixed with fluorescent material then blowing air through the tunnel while exposing the model to an
これによって、揚力や空気抵抗、
さらに騒音の原因の一つである風切り音の発生状況も知ることができ、航空機の設計に役立てられています。
ultraviolet light, the flow pattern of the airframe surface can be visualized.
This makes it possible to understand the aeroacoustic noise generation as well as physics of lift and drag forces of the aircraft. The resulting
information from these experiments is being applied when designing real aircraft.

CONTENTSCONTENTS

P.3-5

P. 3 - 5

P. 3 - 5

P.3-11

P.7-11

特集 日本の航空宇宙技術を芽吹かせ、育てる「基礎的Feature・基盤的技術の研究」
story• Aeronautical Science and Basic Technology Research(3-5)

P.12-15• RoundP.
6 Table9 Discussion “The Future Opened Up by Unmanned Aircraft” (7-11)

P. 6 - 9

見えない空気の流れを正確に捉える世界と競うJAXAの先端風洞技術
P.12-19
Research and development• JAXA’s globally-competitive
advanced wind tunnel technology (12-15)
P.
10-11

P.16-17

P. 1 0 - 1 1• Multiple Small Unmanned Aircraft performing cooperatively (16-17)

次世代の複合材料を生み出し日本の航空宇宙産業の可能性を切り拓く• Creating a next-gen composite material andopening up possibilities
Japan’s
株式会社カネカ先端材料開発研究所
主任研究員
宮内雅彦氏forインタビュー
aerospace industry (18-19)

P.18-19

P.20-21

P. 1 2 - 1 3P.
1 2 -back1 3on the history of Chofu Aerospace Center• Looking

調布航空宇宙センターの歴史を振り返る

P.20-21

P.22
Basic research• Optical Fiber Sensor ResearchP.
14

研究者リレーインタビュー
第１回
P.23 風洞技術開発センター 実機空力セクション
主任研究員 上野 真
• Meeting with IFAR Members in Berlin

P.22

P. 1 4

P.23

P. 1 5

P. 1 5

P.24-25［１］ 「風洞はどのように空気を流しているの？」
航空技術図鑑Flight Path Topics• Progress continues in development of D-NET• Testing a Next-Generation Landing Guidance System with ENRI at New Ishigaki Airport
P.
16• Assessing
Turbulence Information System "ALWIN" at Narita Airport【Flight
PaththeTopics】
PIV measurement data aids device
arrangement design
・•D-NET対応システムの製品化、ますます進む
消防庁は、
D-NETに対応した集中管理型消防防災ヘリ
コプター動態管理システムの運用を開始• Noise measurements
performed around Narita Airport
・新石垣空港でENRIと将来型着陸誘導システムの実験を実施• Second test of D-SEND#2 suspended
・成田空港で乱気流情報提供システム「ALWIN」の評価試験を実施
2

02

P.24
P. 1 6

Feature story: Aeronautical Science and Basic Technology Research

Aeronautical Science and Basic Technology Research

Cultivating and growing Japan’s aerospace technology
In order for new technologies with future potential to be invented, basic research that provides a foundation and research that improvescommon foundation technologies for testing and analysis are indispensable. We asked Masaaki Yanagihara, Senior Chief Officer of Fundamental
Aeronautics Research, for an overview of research into basic and fundamental technology that the JAXA Institute of Aeronautical Technology isundertaking with its "Aeronautical Science and Basic Technology Research" program, and what role this research has in Japan’s aerospace industry.
—Please tell us what the terms “basic technology” andon the four fields of “aerodynamics”, “structure and materials”,—The JAXA Institute of Aeronautical Technology also has the“fundamental technology” mean.

“aircraft engines”, and “flight technology” at the Institute of

Digital Analog Hybrid Wind Tunnel (DAHWIN), which combines

Aeronautical Technology.

wind tunnels and CFD, right?

Basic technology refers to technology that will connect to a

“Aerodynamics” is part of fluid dynamics and is thevariety of projects – for example if we were talking aboutbasis of aviation. There are more than 10 wind tunnels at theYes. CFD calculated by computer does not involve experiments

plants, basic technology would be like the buds that will growInstitute of Aeronautical Technology and these are the devices

and therefore enables effective aerodynamic design. But

into big trees. Fundamental technology is the soil for cultivatingused for aerodynamic experiments. Our greatest selling point

being based on calculations, CFD can differ from actualthat basic technology. Technologies related to facilities andis our ability to perform experiments that correspond to areality. DAHWIN is a hybrid wind tunnel system that combines

testing are considered to be fundamental technologies.

variety of speeds from low speeds to transonic, supersonic,

the best of both efficient CFD and realistic wind tunnel

The concept is that basic technology grows as a result ofand hypersonic speeds. For example, the 6.5 m × 5.5 m low-

experiments, and provides high-precision results with greater

fundamental technology, and will eventually develop into a

speed wind tunnel has a test section that is the largest aircraft

efficiency.

large project.

wind tunnel in Japan. The transonic wind tunnel, which canWind tunnels attempt to be as realistic as possible but

Basic and fundamental technology research areproduce wind speeds of around Mach 1, is used by JAXA (also

are affected by the surrounding walls and the supporting

the unsung heroes – it is because basic technology andby the private sector and other external parties) and has thedevices for the models, so ultimately wind tunnels differ

fundamental technology are in place that large projects canhighest operating ratio of any wind tunnel in Japan. The

from actual flight. As the next step forward from hybrid winddevelop. That is the motivation for our work.

supersonic and hypersonic wind tunnels are used for aircraft

tunnels, we are investigating technology that includes flightand also for rocket and other experiments in the fieldtests. In concrete terms, we are considering comparing dataof space.

measured using JAXA research aircraft to data from wind

—What technologies are included in basic and fundamental
technologies at the JAXA Institute of Aeronautical Technology?

In addition to this variety of wind tunnels, in recent years
we are at the forefront in computational fluid dynamics (CFD),

Research into basic and fundamental technologies is centered

tunnel experiments and CFD, thereby improving accuracy in all
three fields.

used to investigate air flow using computers.

3

Feature story: Aeronautical Science and Basic Technology Research—The JAXA Institute of Aeronautical Technology has the fullBy engaging in this research, JAXA plays a major role

flight technology is that area of research. For example, therange of facilities to enable all aspects of aircraft aerodynamic

in contributing to the development of Japan’s aeronauticalinflight simulator mounted in the MuPAL-α research aircraft

research, from theory through to demonstration, doesn’t it?

industry on the global stage and increasing its share.

is a technology that enables simulated flight of an aircraft forThat is correct. There are many universities that have small—What kind of research is being conducted into the third

passenger plane can be simulated by entering data for thatwind tunnels and CFD capabilities. The advantage of the JAXA

pillar, “aircraft engines”?

kind of aircraft. A simulation of the flight of a new aircraft

which characteristics data has been input. Flight of a large

being developed can be experienced beforehand if data for

Institute of Aeronautical Technology is that under one roof wehave a variety of wind tunnels, as well as CFD capabilities using

The engine of an aircraft is a system on its own and the Institutethat aircraft is input, and, even if problems occur, feedback onsuper computers. Flight experiments with research aircraft areof Aeronautical Technology has many experimental facilities

the design can be obtained prior to manufacture.

also available at JAXA.

relating to engines. We are also researching basic technology
for next-generation engines.

—Please tell us about the second pillar – “structure andmaterials”.

Inflight simulation is also effective in evaluating
newly developed flight technologies. We are researching

Nowadays there is a demand for environmentally-friendly

and developing "Fault Tolerant Flight Control technology"

engine design so we are particularly targeting reduced fuelwhereby a pilot can still safely fly an aircraft even if

consumption and noise.

there are problems such as breakage of the control

In structural and materials technology, JAXA excels in the

The FJR710 engine is a turbo fan engine created undersurface (the helm where the attitude of the aircraft isfield of composite materials such as carbon fiber reinforceda public-private partnership and JAXA was involved in its

controlled). With the inflight simulator function, the pilot

plastics (CFRP). Approximately 35% of the state-of-the-art

development. It was installed in the STOL experimental

can actually disable the control surface during a test flight, andBoeing 787 passenger planes are manufactured in Japan andaircraft “Asuka.” The technology obtained as a result of theif a dangerous situation arises the pilot can stop the inflightthat is because Japan has a high level of composite materials

development of the FJR710 engine led to Japan’s participation

simulation mode immediately and return to normal flight,

technology. I believe that JAXA has made a major contribution

in the international joint development of the V2500 turbo

thereby ensuring safety of the test flight.

to the areas that form the basis for that technology. Currently,

fan engine.

we are researching technologies for making CFRP more
lightweight and more easily manufactured.
We are also conducting research that aims to establish
mass production techniques for, and improve reliability

We want to use environmentally-friendly next-generation—How are research aircraft used?

engine technology developed at the Institute of Aeronautical
Technology to improve Japan’s standing in international joint

Until now we only had a turboprop plane and a helicopter

developments in the aeronautical industry.

so even if we created a new technology for a jet plane thatflies at high speed at high altitudes, we could not sufficientlyof, composite materials that utilize carbon nanotubes, as
new materials for the future. We are also engaged in research—What research is being conducted under the fourth pillar

demonstrate that technology. In 2012 we introduced the jet

into multifunctional composite materials that have new“flight technology”?

plane "Hisho" and now we can, for example, mount devices
in Hisho that are for jet planes manufactured by private-sector

properties, by not only using carbon nanotubes and graphene,etc., as used in the composite materials, but also by combining

The aerodynamic and materials research that I have mentioned

companies, and confirm whether or not the devices operatethese with metal, etc.

ultimately all need to be demonstrated by flight test, andproperly in the actual operational environment of a jet plane.

The 6.5 × 5.5 m low-speed wind tunnel has Japan’s largest
test section for aircraft and is capable of measuring large
models.

The Digital/Analogue Hybrid Wind Tunnel (DAHWIN) can
combine and complement the results of experimental fluid
dynamics (EFD) from wind tunnels and computational fluid
dynamics (CFD) with the supercomputer.

CFRP test piece of VaRTM Prepreg Hybrid (VPH) fabrication
technology, which combines the advantages of autoclave
molding that uses a prepreg (a sheet-shaped member
comprising carbon fiber impregnated by resin) and VaRTM
molding whereby costs are reduced and molding occurs
under atmospheric pressure.

4

We also have a globally top-level technology whereby
pressure-sensitive paint (PSP) is used in measurement
technology for wind tunnel tests and pressure distribution
is optically measured. Although we have some test facilities
which are inferior in size, we make up for it in advanced
technology such as CFD which raises the overall level and puts
us in the international league.
In addition, overseas researchers are collaboratingwith us through international organizations such as theInternational Forum for Aviation Research (IFAR) which isa network of public aviation research and development
institutions from around the world.
—How would you like to see the basic and fundamental
research conducted by the Institute of Aeronautical
Technology playing a role in society?
Operation test of small turbo fan at Altitude Test Facility.

On the tenth anniversary of JAXA, under the corporate
slogan of “Explore to Realize", we announced a broad policy

As a result, Hisho is now being extensively utilized.

by the JAXA Institute of Space and Aeronautical Science, and I

of conducting research that serves a practical purpose in the

believe that our technology can be utilized in that project.

real world. We will continue to conduct research into testing
technologies, facilities, and other fundamental technologies—Could these technologies be used in space?

Fundamental technologies can be used in the aeronautical—What are the differences between basic research beingthat will, of course, contribute to the aerospace field and also

conducted by universities and research by JAXA?

to the global community in a way that provides support frombehind the scenes. Basic technology needs to be researchedfield and in a variety of other fields, including space. For
example, we use CFD technology to analyze acoustic vibration

There is an international index called the Technology

with a clear vision in mind as to how that research is goingof rockets and investigate the effect on satellites to which they

Readiness Level (TRL) which indicates, in levels from 1 to 9,

to benefit society in 10 or 20 years’ time. We also need to be

are mounted; we use wind tunnel technology to investigate

the practicality of a technology. Universities undertake basic

proactive about providing information so that people canthe aerodynamic characteristics in the atmosphere of a reentry

research at levels 1 to 3, aircraft manufacturers, etc., researchunderstand the research that we are undertaking.

capsule returning to earth; and we perform experiments onin fields close to practical application at levels 6 to 9, and JAXA

landing radar mounted to lunar and planetary probes, by using

researches technology in between, corresponding

experimental aircraft. CFRP and other composite materials areto levels 3 to 6.

used in satellites. We are cooperating in the development of an

The difference lies in our respective

aircraft for probing Mars, which is currently being researchedroles – JAXA takes the research conductedin university laboratories, demonstrates
those technologies using wind tunnel
tests or flight experiments or puts thosetechnologies together as a system, raises
the TRL, and passes those technologies on to

Masaaki Yanagihara
Senior Chief Officer ofFundamental Aeronautics
Researchthe manufacturers.
—What technologies do you have thatare leading the world?

Our CFD and composite materials
technologies are ahead of
the rest of the world.

Research aircraft: jet “Hisho” (top) and turboprop “MuPAL-α”
with in-flight simulator (bottom).

5Feature story: Unmanned Aircraft
Round Table
Discussion

JAXA Researchers Explain“The Future Opened Up by Unmanned Aircraft”

Aircraft with no people aboard – unmanned aircraft – are used in a variety of applications
such as crop spraying and aerial photography and new demand and potential have emergedin the areas of crime prevention, monitoring, and home delivery services. In the round-tablediscussion, researchers at the JAXA Institute of Aeronautical Technology discussed today’s
unmanned vehicles, the issues faced, and the type of vehicles JAXA is striving for.
■ What is an Unmanned Vehicle?

● ATTenDees (Interviewer: Mizuno, editorial Dept.)
be included in that category. “Flying” unmanned vehicles arecalled “Unmanned Aerial Vehicles” or “Unmanned Air Vehicles,”the term “unmanned vehicles” is often heard

abbreviated to “UAV.” Other terms used in recent years include

these days, but what are they?

“Unmanned Aircraft System” (UAS) indicating not only theaircraft itself but the overall system including on-groundishikawa: One of the main characteristics of unmanned

facilities, and “Remotely Piloted Aircraft System” (RPAS)

vehicles is the ability to perform work without a pilot onemphasizing the remote operation. In the United States theboard, by being operated remotely or automatically.

media favors the term “drone.”

Kubo: “Unmanned vehicle” is a general term for all unmanned

Kohno: There are a variety of unmanned vehicles and theyvehicles and some space probes and artificial satellites mighttend to be largely grouped into two categories. One is the

Kazutoshi ishikawa, Director,

Operation Systems and Safety
Technology Research Grouptakashi Kohno, Section Leader,
Unmanned Aircraft Systems Safety
Technology Section, Operation Systems andSafety Technology Research Groupdaisuke Kubo, Unmanned Aircraft

Systems Technology Section,
Operation Systems and Safety
Technology Research GroupKoji muraoka, Team Leader,

UARMS Team, Technology Demonstration
Research Office127Feature story: Unmanned Aircraft“large” category, which have similar performance and size as
piloted aircraft and often fly together with piloted aircraft. The
other main category is “small” such as those derived from model
planes, they cannot carry the same equipment as manned aircraft
but can be inexpensively and readily produced.
What technology is required to fly unmanned
aircraft and what issues are faced when trying tocreate that technology?
Ishikawa: One of the advantages of unmanned vehicles is theirability to perform work without being piloted, so they are usefulfor dangerous, dirty, and dull work – known as “3D” work. Thismight be long-term observation of the same location or routeor flying in to observe places too dangerous for people, suchas typhoons. So the applications vary and a technology needs
to be developed for each.
Another advantage of unmanned aircraft is they can be madesmaller and lighter because no space is required for people.

A conceptual image of the high-altitude long-endurance unmanned aircraft system that enables continuous
observation for 72 hours.

Kohno: Given that there is no pilot on board, technology tocommunications system for sending information to the groundwill make flight more intelligent by utilizing on-line rerouting,replace the functions of the pilot is needed. This technology needs

about the aircraft and its surrounds as measured by the sensors

swarming and so on.

to cover three stages of tasks performed by pilots – observation,and to send instructions from the ground to the unmanned

determination, and operation. Example technologies include

aircraft.

■ UnManned aIrcraft researched anddeveloped by JaXa

sensors that measure position using GPS and measure speed, tocover the “observation” stage, flight control computers that makeMuraoka: Technologies for safe flight are also the key issues.

“determinations” based on the information from those sensors,

There are, for example, some redundant on-board automatic flight

What kind of unmanned aircraft is the focus

and actuators that perform the “operation” function by controlling

termination systems (to prevent fatal impact on people or objectsof your r&d at the JaXa Institute of aeronautical

the aircraft in accordance with the determination results.

on the ground), and so on.

technology?

With regard to pilot-replacement technology,

Ishikawa: There are two main types of R&D. One is researchwhat is happening with autonomous flightinto using unmanned aircraft as a tool for flight experiments oftechnology where the unmanned aircraft canaeronautical technologies. An example of this is the experimental

think for itself and fly?

supersonic airplane used in the D-SEND project.

Muraoka: We are jointly researching and developing ansocial infrastructure. We conducted R&D into a disaster-monitoring“Unmanned Airplane for Radiation Monitoring System (UARMS)”

unmanned aerial vehicle system, up to 2012, whereby unmanned

together with the Japan Atomic Energy Agency (JAEA),

aircraft could be deployed by local government personnel when

for radiation measurement over a wide range. The UARMS

disasters occur, to ascertain the scale of the disaster and theflies automatically on the predetermined flight route. It isdamage caused. We are also researching a system whereby

quite a conventional automatic function. In themultiple small unmanned aircraft called Micro Aerial Vehicles

future, the use of automatic technologies(MAV) can be operated cooperatively and flown inside collapsed

One more element not required in piloted aircraft is a

The other is R&D to enable unmanned aircraft to be used for

Kazutoshi Ishikawa

Director, Operation Systems and Safety
Technology Research Group8

Koji Muraoka

Team Leader, UARMS Team, Technology
Demonstration Development Officebuildings after a disaster such as a tunnel collapse or earthquake,

Ishikawa: We are also considering a high-and search for survivors and check for fires and toxic gases. (Seealtitude long-endurance unmanned aircraft

report on page 15)

system capable of flying continuously at highThe other focus of our R&D is the “Unmanned Airplane for

altitudes for 72 hours. The concept is to have 24-

Radiation Monitoring System (UARMS)” already mentioned.

hour monitoring throughout the year by rotating
between unmanned vehicles capable of 72-

Muraoka: We had already worked on an unmanned fixed-winghour flight shifts, which could be used to monitor

aircraft capable of 21 hours continuous flight and thought weJapan’s extensive territorial waters and to provide

could develop an unmanned aircraft based on this technology that

continuous monitoring of and information about

would be optimal for radiation monitoring, so we started R&D onchanging conditions at disaster sites.

the UARMS, jointly with JAEA after the Fukushima Nuclear Power
Plant accident. We are currently conducting flight tests and expect

by manned helicopter is quite reliable but the costs are higher andto complete the project this year. Once completed, the unmanned

they cannot fly at lower altitudes – which is desirable for radiation

aircraft will be capable of radiation monitoring during longmonitoring because of minimum safety altitude restrictions undercontinuous flight over a 20 to 40 kilometer range.

■ legal IssUes WIth UnManned aIrcraft
how are unmanned aircraft handled in law?

the Civil Aeronautics Act. Unmanned helicopters can fly lower andKohno: In the law relating to aircraft, the Civil Aeronautics

Current aerial radiation monitoring uses both manned andslower but long and wide range flight performance is not so good.

unmanned helicopters. The UARMS has been developed to

The advantages of the UARMS are they can fly at higher speed, at

Act, aircraft are defined as a device that can be used for air

lower altitude, and for longer distances.

navigation with a person on board (Article 2). The Act doesn’tcompliment their operations by adding fixed-wing UAV. Operations

Unmanned Airplane for Radiation Monitoring System (UARMS) experiment).

9Feature story: Unmanned Aircraft

cover unmanned aircraft although it does provide for a piloted
aircraft modified such that the pilot can disembark, called “pilotlessaircraft” (Article 87). The Act does not consider a machine
fundamentally designed to be without a pilot to be an aircraft.
So, under the current Civil Aeronautics Act, unmanned aircraft are
not specified as aircraft.
Ishikawa: The other relevant law is the “Aircraft Manufacturing
Industry Act” which stipulates that a license must be obtained
and required equipment in place when manufacturing aircraft
having a total weight of over 150 kg. This means that large

Above: Disaster-monitoring
unmanned aerial vehicle launchfrom a catapult mounted on atruck tray.
Left: flight testing of the disastermonitoring unmanned aerial
vehicle system using cameras
to capture images from above adisaster site.

unmanned aircraft of that size require the same level of reliability,
safety and airworthiness as piloted aircraft.
It seems that relevant legislations are being
developed in the US and other countries.
What about in Japan?

Kohno: Unmanned helicopters for crop spraying are used

Transport and Tourism.

have to warn the fire brigade and the police. These proceduresSuperpower – but operators follow voluntary operation rules

Ishikawa: Although not strictly relevant to legislature, there

need reviewing when unmanned aircraf t come to beprovided by the Japan Agricultural Aviation Association andare also complicated procedures in place for conducting flightused in everyday applications.

the Japan UAV Association, which is the industry body.

experiments using unmanned aircraft. We have to apply for

widely in Japan – so much so that we are often called a UAV

Our unmanned aircraft experiments are conducted under

are necessary in the experimental stage, of course, but willaviation authority and airport permits as well as notify local■ IncreaSIngly WIdeSpread USe of
Unmanned aIrcraft

JAXA’s strict safety standards and we make suggestions

government authorities and residents when we conduct wide-

for improving Japan’s legislation, on the basis of ourranging flights. We have to liaise with the Coast Guard andexperiment results, to the Ministry of Land, Infrastructure,

the fishing industry when flying over the ocean and we also

Yamaha Motor’s unmanned helicopter
for industrial use “fAZeR.” Yamaha has along track record in the use of unmanned
industrial-use helicopters.
Images: Yamaha Motor Co., Ltdtakashi Kohno

Section Leader, Unmanned Aircraft Systems
Safety Technology Section, Operation Systems
and Safety Technology Research Group10

How are unmanned aircraft used now and what

daisuke Kubo

Unmanned Aircraft Systems Technology
Section, Operation Systems and Safety
Technology Research Groupmight they be used for in the future?

bridges and tunnels.
Regular inspections have not been compulsory in the

Kohno: An increasing number of companies in Europe are using

past but are likely to become so and the cost of inspections

small unmanned multi-propeller aircraft, called “multicopters,”

using scaffolding is enormous. Unmanned aircraft have great

to provide a variety of services. Aerial photography is thepotential because of their ability to inspect from the air, without

most common but other applications include using infrared

requiring scaffolding.

cameras to observe crops from the air and creating 3D maps fromaerial surveying.

are passenger jets and other

America hasn’t developed commercial use as much as Europe

large aircraft likely to be

but government bodies use comparatively large unmanned aircraft

unpiloted in the future?

to patrol borders and monitor for bush fires, etc.
Ishikawa: Research into unmanned
Ishikawa: As already mentioned, unmanned helicopters are

au t o m o b i l e s ( Unm a nn e d G r an dwidely used in Japan for crop spraying. They suit Japanese

Vehicle, UGV ) is under way now

conditions where the agricultural land is close to housing andand the day is approaching when

the cultivated area is relatively small.

unmanned work vehicles will be used in the civil engineering/skies but, as with unmanned automobiles, there are many social

construction sector and unmanned tractors will be used inrules and ethical issues that would need to be overcome first.

Kubo: One area that unmanned aircraft have great potential,

agriculture. Technologically speaking, it is conceivable that

not only in Japan, is for infrastructure inspections, e.g., foreventually an unpiloted passenger jet could be flying the

These days we hear a lot about theuse of unmanned aircraft to provide
a variety of services. There are manypotential applications and they will
no doubt become an increasingly
familiar technology into the future.
However, technological andlegislative issues need to be overcome
before expanding the use of theseaircraft. The Institute of Aeronautical
Technology has challenges ahead inorder to achieve its goal of utilizing
unmanned aircraft technology tocontribute to a safe and securesociety.

Micro Aerial vehicle (MAv). Aiming to perform complicated tasks with multiple cooperative operation.

11

Accurately ascertaining invisible air flow

JAXA’s globally-competitive advanced
wind tunnel technology
Wind tunnels are experimental facilities for artificiallycreating airflow and investigating characteristics of the
airflow around a model placed inside it. There is a long
history behind wind tunnels. The Wright brothers, who
successfully conducted the first ever powered flight,
repeatedly conducted tests in a wind tunnel before theirflight tests. Wind tunnels, with their extensive history,
are indispensable to modern day aircraft and spacecraft
development and are evolving as a result of constantly
updated technology. The JAXA Chofu Aerospace Center
began its history with the introduction of wind tunnels.
Here we look at JAXA wind tunnel technology that
supports aircraft and spacecraft development.

Shigeru Hamamoto
Director of the Wind
Tunnel Technology
Center■ What do wind tunnel tests reveal?

Aerodynamic design involves investigating what impact“Aerodynamic design is the most impor tant element in(aerodynamic characteristics) airflow has on a body. By repeatedly

In wind tunnel tests, firstly the model is arranged in the testchange with temperature, so temperature data is also required.

determining the shape of an aircraft body” – so says Shigeru

reflecting this data in the process of designing, the final bodysection inside the tunnel and sensors that measure the data are

Hamamoto, Director of the Wind Tunnel Technology Center, whichshape is determined in line with the purpose of the aircraft,

wired up. Then, with air being blown through the wind tunnel,

conducts research and development of wind tunnel technology.

e.g., the need to be faster or more efficient. Since the time of

the angle of attack for the model (the vertical angle of the model

the Wright brothers, models of

relative to the air flow) and the lateral sliding angle (yaw angle)

bodies have been placed in wind

are changed and measurements taken. Depending on the scale oftunnels to establish how the force

the experiment, the series of steps, from installation of the modelof air acts on the model during

to ventilation, measurement, and removal takes approximately one

simulation of flight in a state thatto two weeks.

is close to actual flight. These windtunnel experiments have been

■ Diverse wind tunnels covering a wide

indispensable to aircraft design

range of speeds

Aerodynamic force has a

Replica wind tunnel device used by the Wright brothers. Image: U.S. Air Force.

1206

variety of elements, such as theAircraft flight speed varies, from the comparatively low speed offorce that lifts up an aircraft (lift),helicopters to the high speed of jet aircraft, and the even fasterthe force that tries to push backsupersonic aircraft. The Institute of Aeronautical Technology owns

the aircraft (drag), the force thatmany wind tunnels that cover a wide range of speeds, from low-

tries to rotate the aircraft around

speed wind tunnels capable of creating a state in take off andthe center of gravity (moment),

landing, to transonic wind tunnels that simulate a cruising state, toand the pressure applied to thethe even faster supersonic and hypersonic wind tunnels. There isbody surface. The properties of air

also an arc-heated wind tunnel and an inductively-coupled plasma

RAnge of Wind Tunnels
1 m × 1 m supersonic wind tunnel. Used for research and development of aircraft, projectiles,
rockets, and reusable space transportation/re-entry vehicles, etc.

6.5 m × 5.5 m low-speed wind tunnel with aircraft model.
The wind tunnel has the largest test section in Japan andis used for investigating aircraft characteristics during
landing and takeoff, and during low-speed flight.

1.27 m hypersonic wind tunnel.
Capable of producing Mach
10 wind speeds. Used for thedesign of future hypersonicaircraft and reusable spacetransportation, etc.

750 kW arc-heated windtunnel, capable of creatinga high energy air flow andof facilitating experiments
simulating re-entry to theatmosphere. The image showsa heating experiment on lowdensity ablators.

2 m × 2 m transonic wind tunnel. Used for investigating characteristics of aircraft that fly attransonic speeds.

wind tunnel that applies high energy to the airflow to simulate therockets that fly into space, however the period from when thestate of a re-entry capsule returning to Earth from space.

rocket leaves the atmospheric layer until it reaches space is

Measurement technology for wind tunnels is rapidly

extremely important, and we need to measure the effect of safetyadvancing. Fifty years ago the force applied to models was

efficient fans, etc.

■ Contributing to Japan’s aerospace industry for

devices (stabilizers) on making the rocket fly straight. We also

ascertained using instrumentation that measured mechanicalmore than 50 years

need to measure the effect of the vibration phenomena that occur

balance. This balance was read by the human eye and calculated

when exceeding the speed of sound. For example, experimentsby hand, but these days we have changed from mechanicalwere conducted for the H-II rocket and the H-II B rocket, using

measurement to electronic measurement using strain gauge
sensors and from human calculation to computer processing.

It is more than 50 years since the 2 m × 2 m transonic windtunnel started operation in 1960 and this wind tunnel has

the wind tunnel to find how aerodynamic characteristics changed

been used in nearly all aircraft development that has taken

depending on the attachment position of boosters.

place in Japan during that time. In recent years, it was used

Many of the wind tunnels at the JAXA Chofu Aerospace Centerprogressed. In the past, a manometer that derived differences induring the development of the Mitsubishi Regional Jet (MRJ).

were completed years ago but they are still active and operating.

air pressure from the height difference of a liquid surface was used

Experiments were also conducted in this wind tunnel during the

It is not easy to rebuild an aged wind tunnel but improvements

and people visually measured the values. That has now changed

development of rockets such as the N-series and the H-series.

and modifications are continually occurring, such as updating

to more precise measurement made possible by a pressure sensor

People may think that aerodynamics have little to do withelectronic devices and replacing the drive motors with morethat outputs, as electric signals, very small deformation amounts

The technology for measuring air pressure on models has also

13
07

JAXA’s globally-competitive advanced wind tunnel technology

of diaphragm caused by pressure. Furthermore, a pressure scannerhas been developed that is capable of measuring pressure at many
points in a short amount of time – by rapidly switching between
inputs from multiple pressure sensors. The pressure scanner canmeasure more than 500 points in one second.
■ Pressure-sensitive paint measurement tovisualize pressure images on a model surface
Measurement methods continued to evolve, but there was still
an issue – the sensors could only measure the pressure at the
points where they were located. There is a limit to the number of
sensors that can be arranged on a surface, and there will be gaps
between the pressure sensors. The pressure in the area between
the sensors can only be inferred from the values measured byadjacent sensors. If an unusual phenomenon occurs, errors cannot
be detected if there is no pressure sensor at that location.

Pressure-sensitive paint (PSP) is light-emitting paint that changes brightness according to pressure. Pressure
distribution is measured as an image, by measuring luminescent intensity from the PSP, using CCD cameras, etc.
By coating PSP on a model, the pressure distribution for the entire surface can be measured. The redder the color,the higher the pressure - see below.

This issue had been identified for a long time and many
researchers wanted to be able to measure the pressure not of a
■ Particle Image Velocimetry making air flow inpoint but of a plane. Pressure image measurement was realized byAmerica and Russia started research into PSP in the latter half

technology using pressure-sensitive paint (PSP), which changesof the 1980s and Germany and France have also developed. JAXA

the amount of luminescence intensity on the basis of the amount

has successfully implemented PSP technology in a large-scaleof oxygen (partial pressure). When a model coated in pressure-wind tunnel. Kazunori Mitsuo, Chief Manager for Planning at the

In order to understand aerodynamic force, it is important tosensitive paint is placed inside the wind tunnel and wind andWind Tunnel Technology Center states “JAXA’s PSP technology isunderstand airflow around the model. There are methods thatultraviolet light are applied to the model, the degree of red lightinternationally competitive at the top level.”use smoke, such as in smoke wind tunnels, in order to examine

space visible

emitted by the paint changes depending on the difference in

Pressure images measured using PSP aid intuitive

slow flows, but Particle Image Velocimetry (PIV) is a technology

pressure. When this is acquired by a CCD camera and image-under s t anding f orthat is one step further advanced. With this technology the speed

processed, the pressure distribution on the model surface can beresearchers. However

distribution, direction, and behavior of airflow around wings canviewed as an image.

this is not as accurate as apressure sensor (electrical pressure

be observed.
When PIV is used, vortex movement induced near wingtransducer). For that reason we perform

tip can be captured. The aircraft in flight is pulled along by themeasurements that combine conventionalvortices and unforeseen force is applied when a vortex collapses.

methods and PSP technology, such as coating PSP
on the entire surface of a model with an arrangement ofpressure sensors, thereby ensuring accuracy.

PIV is very useful in researching this phenomenon.
The principle of PIV is simple – small particles called tracers
are mixed into air and caused to flow, and tracers that passthrough a laser light irradiated in a sheet pattern (a laser sheet)are captured by camera. After a certain interval another image istaken and the two images are compared. If the distance traveledby the same particles is known, their velocity can be calculated,
and, therefore, the velocity distribution on the imaged plane
can be found. The principle is simple, but given that many tens of
thousands of particles are captured in one image, identificationof the particles by the human eye is not possible.

1408

MEAsurIng
ArEA

obsErVAtIon
WIndoWlAsEr shEEt

cAMErA

LEFT: PIV measurement concept diagram. Tracers released
in air are captured, by camera, when they come in contact
with a laser and emit light.

ModEl

g

AIr floW

BELOW: PIV measurement results. Vortices created at wingtips (wingtip vortices), turbulence generated behind thewings (wing slipstream), and turbulence created by engine
section (engine nacelle slipstream) can be visualized .

cAMErAFor that reason, the images are processed by computer, theparticle travel amount is calculated using a method called cross-

Wingtip vortices

correlation analysis, and the velocity distribution calculated. A
measurement system using PIV was customized for use in JAXA

Wingtip slipstream

wind tunnels and has been implemented. By using the customized
JAXA PIV, three-dimensional velocity vectors can be measured, byusing two cameras and imaging the same sheet area. Furthermore,
the airflow for large models can be observed by changing theEngine nacelle slipstream

position of the laser sheet and the camera.
■ Evolution that meets user needs
Transonic wind tunnels of ten years ago showed slight variationsin the obtained data because the temperature of airflow andmeasurement devices changes with the time of day and thesound does not reverberate.

Tunnel Technology Center, Shigeru Hamamoto, spoke of his

We are also currently engaged in even more innovative

aspirations: “We are aiming for JAXA to have good wind tunnels,

seasons. Competition is fierce in the modern aviation industry,technology – the development of measurement technology

excellent wind tunnel testing/measuring technology, and theparticularly in relation to environmental performance and fuelfor skin friction (surface friction) using light-emitting oil. Thisability to repond to the diverse demands of the global community.

consumption, so even slight variations can have a large impact

technology has not been successfully implemented anywhere inThis will prove that we are world class.”

on design.

the world yet, so it should become a predominant technology

We are constantly modifying the test environment andonce it is achieved.

measurement methods so as to respond to user needs and get
closer to consistently obtaining the same measurement data.

■ Aiming for internationally first class wind tunnel

Although this kind of work is painstaking, we have been able totechnology

achieve globally competitive, high-precision wind tunnels as aresult of revealing, in detail, the issues involved and accumulating

The JAXA wind tunnels are available for use by organizations

technological developments in this way. In addition, attention has

outside of JAXA, through the collaborative use system. The

recently been focused on one of the environmental efficiencies

transonic wind tunnels are used, for example, by companies– noise reduction – and, as a result, there is demand for winddeveloping aircraft and spacecraft. The low-speed wind tunnels

tunnel measurement of noise generated by the body. Accurate

are used for windmills, wind power generation, and antenna formeasurement is not possible if the noise generated by the windmaritime radar. In addition, this technology is used in the sporting

tunnel itself is larger than the body noise being measured. We

field, for example luge and ski jump competition.

have been able to make improvements to facilitate more accurate

The JAXA Wind Tunnel Vision 2025 has been adopted at the Wind

measurement of the sound emitted by a model, by making

Tunnel Technology Center as a guiding principle for research,

modifications such as coating the internal walls of the wind pathdevelopment and management of future wind tunnel technology.

with sound-absorbing material, which reduces the fan noise,

One of the targets of the Vision is the research and development

and by employing an anechoic measurement chamber in whichof world-class wind tunnel technology. The director of the Wind

Kazunori Mitsuo
Chief Manager for
Planning and Section
Leader, Supersonic andFlutter Wind Tunnel,
Wind Tunnel Technology
Center15
09

A message to JAXA's Institute of Aeronautical Technology

Creating a next-gen
composite material andopening up possibilities forJapan's aerospace industry
KANEKA CORPORATION's Advanced Materials
Research Laboratory
Interview with Masahiko Miyauchi, Senior Researcher
Here at the JAXA’s Institute of Aeronautical Technology, we are working on research into polyimide/carbon-fiber
composite materials used in the aerospace field. Through collaborative research with KANEKA, we have developed apolyimide resin with excellent heat resistance and toughness (strength against tension and impact) and are making
progress toward creating composite materials that use this new resin. We asked Masahiko Miyauchi, senior researcher
at KANEKA's Advanced Materials Research Laboratory, about the results of teaming up with JAXA.

— What sort of joint research with JAXA have you— Please tell us about the background of yourreduced. Because wing surface temperatures exceed 200 °C when

been making progress on?

research.

flying above Mach 2, it was necessary to develop a new heat-

At KANEKA, we are producing polyimide film, a synthetic resin.

Research into composite materials that use polyimide resins began

resistant composite material to replace the epoxy resin.
Polyimide resins have outstanding heat-resisting properties and are

at NASA over 50 years ago. They were unable to manage bothused primarily in the wiring of electronic devices and in multilayer

heat-resisting properties and moldability, though, and the conceptheat-insulating materials used to protect spacecraft from heat.

was never truly realized. Meanwhile, research led by Rikio Yokota

These polyimide resins are often used in the form of a thin film, but(then with the Institute of Space and Astronautical Science (ISAS))

we are attempting to use them together with carbon fiber to makeinto polyimide resins continued to progress at JAXA, and througha composite that can be utilized in aircraft structural materials.

— Tell us about the results of the joint research.

fundamental technological research—supported by NEDO (NewThe structural material of aircraft is primarily aluminum andEnergy and Industrial Technology Development Organization)titanium alloys, although lately CFRP (carbon fiber–reinforced

and carried out for a five-year period starting in 2002—a newplastic) made from an epoxy resin has entered wide usage.

technique for developing polyimide resin with excellent moldability

However, epoxy-resin CFRP can only endure continuous-usage

and heat resistance was developed. When this research ended

temperatures of about 120 °C, so highly heat-resistant titanium

in 2007, as a resin manufacturer we entered into collaborativeis used in locations that can reach temperatures of 200 °C, suchresearch with JAXA.

as those near engines. We aim to replace this titanium with apolyimide-resin composite material, making the airframe of an— At the time, what was Yokota thinking aboutaircraft even more lightweight and reducing fuel consumption.

using the polyimide-resin composite material on?.
On ultra-high-speed aircraft with cruising speeds surpassing
Mach 2. To make this a reality, the weight of the airframe must be

16
10

Polyimide resin material is used for the sail componentof the Small Solar Power Sail Demonstrator "IKAROS"(image: CG), and also as thermal insulation material
for other satellites.

— What originally prompted the collaborative
research with JAXA to take off?
When we were considering expanding the business of our resin
division, the aviation and space field seemed extremely attractive.
We estimated that these markets will definitely continue to grow in
Carbon-fiber composite material formed by laminating layers of sheets coatedwith oligomeric imide resin (the top plate in the picture).

the future. We had already developed an epoxy-resin strengthening
agent for composite materials in these fields, which has since beencommercialized as an additive (masterbatch). From that point, weFirst, the production method for the polyimide-resin composite

area and thickness would be about one-third of the weight.

material developed by NEDO was as follows. Start by creating awere thinking to expand our composite material business by using
polyimide resins.

sheet of carbon fiber impregnated (pre-preg) with an oligomeric— Where specifically on an aircraft are you looking

amide resin solution, which is a precursor for polyimide. Then

to use this material?

—Still, the development of composite materials
for aircraft takes a long time. It doesn't create newlaminate this with many layers, and cure it thermally (giving ita high molecular weight) while applying pressure in a type of

We are aiming to replace titanium alloy in the components ofbusiness immediately. It's impressive that you

furnace called an autoclave. However, there is a problem with thisjet-engine fan blades with polyimide-resin composite material.

made that decision as a company. What are some of

method: the process of oligomeric amide converting to oligomeric

We would also like to use it in places such as around the engine

the good points about collaborating with JAXA on

imide during molding generates water molecules, which make it

nacelles and the pylons attaching engines to wings.

research?

easy for cracks to form in the materials. During the joint researchwith our company into solving this problem, Yokota and his team

— What are some of the challenges moving

Since the 1980s, we've continued our research into creating

discovered that the issue could be solved by utilizing an oligomericforward?

polyimide-resin film while trying out various molecular structures.

imide having ingredients with particular chemical structures.
Applying this method, we worked together with JAXA to develop

However, since about the year 2000 we have primarily conducted
We are now able to manufacture the material in sheets, but whenapplied research, developing in a short time a great numbera polyimide-resin composite material called TriA-X, which we

we consider using it in practice we realize that we have to beof resins in accordance with the request of our customers—announced in 2008. TriA-X is a very tough material able to resist

able to produce three-dimensional shapes. Therefore, we needresins which are intended for use in cellular and smartphone

temperatures of over 370 °C. Following that, in 2011 we developed

to produce some I-shaped and C-shaped components as well ascomponents. So when we think back to our company's polyimide

a new polyimide-resin composite material with an even higher

some large-scale pieces then investigate their strength. To evaluate

resin technology, we see the need now more than ever to expand

moldability.

whether or not this material can be used in practice, we need toour techniques for evaluating and designing the molecules ofaccumulate reliable strength data and consider its ability to beresins, as they will become the basis for the development of new— What is involved in that method?

mass-produced.

products.

Although the composite that can be obtained from pre-preg— What is the next objective in your joint research

conducting fundamental research from designing polyimide

molding is high quality, it is also expensive. For manufacturingwith JAXA?

high polymers to evaluating the properties of the resulting

This means that there is significant meaning to consistently

large numbers of components with identical shapes or those withresins, together with developing highly heat-resistant composite

complex shapes, a better process is resin transfer molding (RTM),

We are trying even more ways to make new polyimide-resinmaterials as applied research. And not just with this collaborative

which involves directly impregnating pre-laminated carbon fiber

composite materials. The jointly-developed oligomeric imide we

research—we have expanded the range of our research intowith a liquid resin. As the RTM technique can only be applied using

spoke of a bit ago has a high solubility, but because it has a highcreating polyimides within our own laboratories, as well. Our

a resin with an extremely low viscosity, we have developed aaffinity to the solvent, as the mold sheet gets thicker there is a

joint research with JAXA has had a ripple effect, stimulating

polyimide resin with a low melt viscosity based on TriA-X.

chance the solvent will be difficult to remove from the laminatedfundamental research within our company.

pre-preg portion within the mold. So, we are thinking about boldly

Looking forward, we are greatly anticipating JAXA's— If you replace titanium with this material, aboutchanging the process by dissolving the polyimide resin ingredients

Institute of Aeronautical Technology working toward full-fledged

how much would you be able to reduce the weight?

in a solvent with a low boiling point then casting the composite.

implementations of heat-resistant composite materials; creatingThis would mean that the process of creating the imide froma foundation for further applied development systems along with

Aircraft titanium alloy has a density of around 4.4. Polyimide-resin

oligomeric amide, hardening it and molding into a sheet could bea cooperative framework for manufacturers in all sectors; andcomposite material is about 1.5, so a sheet of the same surface

done all in single process.

serving as the nucleus that carries the aviation industry of Japan.

17
11ReseaRch into “coopeRative opeRationof Multiple MicRo aeRial vehicles foR
coMplex Mission capabilities”

Multiple small unmanned aircraft
performing cooperatively
These days, the performance of small unmanned aircraft is very highand they are being increasingly utilized in commercial applications.
At JAXA we are researching a system for indoor rescue support, such as
in collapsed tunnels or buildings in the aftermath of a disaster, using
multiple small unmanned aircraft operating cooperatively.

system for multiple Cooperating

are being increasingly used for aerial photography and disasterthe example application of “disaster sites inaccessible to rescue

maV performing Various tasks

damage evaluation

workers, such as indoor fires and collapsed tunnels.” If small flying

The research into “Cooperative Operation of Multiple Micro

MAV stands for “Micro Aerial Vehicle” – ultra-small unmanned

Aerial Vehicles for Complex Mission Capabilities,” being conductedrobots can first check the situation inside inaccessible sites thatpose risks to people, then rescue can proceed swiftly and safely.

aircraft that, at most, are only tens of centimeters in size. The

by the JAXA Institute of Aeronautical Technology aims to provide a

What are the merits of using multiple MAVs for such tasks?

multi-rotor vehicle used as a platform in this research uses a

system capable of independent response to complicated tasks byRadio waves may not penetrate some disaster sites due tosystem without complicated mechanisms, that simply combines

cooperative operation of multiple MAVs, indoors where GPS cannot

collapsed walls and ceilings, but that issue is resolved and all areas

electric motor driven propellers and a control system. Simple MAV

reach. Daisuke Kubo, researcher with the Operation Systems andcan be searched if multiple MAVs are used to relay the radio waves.

are available in the hobby market and advanced-function MAV

Safety Technology Research Group conducting this research, gives

If there are several MAV operating, the task of an accidentally
damaged MAV – which is always possible at a disaster site – canbe taken over by another.
Greater efficiency is achieved because each MAV is
performing a different task.

indoor navigation without gPS“It is the same as when one person is searching for somethingmav
Search Scanad hoccommunicationS
network

inside a building – it takes a lot of effort and time. But many
people, working together and communicating effectively by radio
can find things so much faster.” (Kubo)

diffiCulty of aChieVing stableindoor flight

One essential technology in this research is the technology

autonomouSdePloyment andoPtimum taSk allocation
Contr ols tation

swift searChes at sites
inaCCessible to humans

Safe mav
Platformeasy due to the absence of wind and other outdoor factors.
But in confined spaces MAV generate their own air currents

coordination withunmanned groundvehicleS

Concept drawing. Several MAV communicating and exchanging
information to perform tasks. MAV can penetrate sites out of radio range,
by relaying radio waves. One MAV can take over if another is damaged.
18

for stable indoor flight. At first glance, indoor flight may seem

which reflect off the walls and destabilize the MAV and affectthe flight of other MAV.
Also, absolute position can be easily obtained duringoutside flight by using GPS, but position cannot be determinedthe entire indoor space. Another problem is the comparatively
heavy weight of the LIDAR itself, which increases the size of theoverall vehicle.

how are multiple maVs
Coordinated?

One more important issue is “task generation and planning” –technology whereby a computer allocates the optimum task
to each MAV and plans efficiency during operation of multiple
MAVs. This involves a series of decisions and instructions, suchas determining which MAV is closest to the target, which MAV
will arrive first, and the issuing of instructions to that MAV. An
experienced operator can make decisions for each situation andoperate one or two MAV accordingly, but management of a fleetof MAVs is difficult no matter how experienced the operator.
To achieve a system that anyone can easily use, “we areaiming at an optimum and efficient method whereby an operator
only need give basic instructions and the rest is handled by theoverall system.” (Kubo).
Although still at the initial research stage,“ we hope to beable to test several units by 2015,” Kubo explains enthusiastically.
However many technical issues must be resolved first.
Unmanned aircraft technology has a wide range ofapplications. If we can achieve stable indoor flight of MAV, theday may come where MAV can be used in our everyday lives andnot just in disaster situations as foreseen by the current research.

daisuke kubo

Unmanned Aircraft Systems Technology
Section, Operation Systems and Safety
Technology Research Group

Coordinated flying of multiple MAVs.

indoors because there is no GPS signal. Knowing where you

the LIDAR method that utilizes a laser light sensor. The LIDAR

are is extremely important for safe flight. It is relatively easymeasurement method measures distance from walls andto ascertain position, even indoors, if building plans can be

obstacles and creates a map of the surrounds to ascertain

entered into a program beforehand – but this doesn’t work inposition. Kubo explains “The research has progressed to a pointa disaster, where conditions inside the building will most likely

where the shape of the room and position of the vehicle can behave changed.

ascertained to a certain degree.” However, onboard LIDAR can only

There are several methods for a MAV to determine its

measure planar (two dimensional) data, so MAV attitude (laser

surroundings, one method uses images and another uses

direction) and altitude need to be changed to be able to measure

19

Looking back on the historyof Chofu Aerospace Center
Susumu Toda
Former Head, National Aerospace Laboratory
Former Executive Director JAXA

The forerunner to the JAXA Institute of Aeronautical Technology,
the National Aeronautical Laboratory of Japan [later the National
Aerospace Laboratory (NAL)] was founded in 1955. Since that time, avariety of test facilities that support aeronautical and space technology
research have been created at the Chofu Aerospace Center and thegenes of that research and development have continued to be handed
down in an unbroken line. Let’s look at part of that history, from theperspective of Susumu Toda (former Head of NAL) who is familiar withthe period when Chofu Aerospace Center was established.

■ Reclaiming 7 blank years – to make aeronauticaltechnology world class
Susumu Toda recalls “I joined the National Aerospace Laboratory(NAL) about 10 years after it was founded. At that time it was
surrounded by fallow fields and there wasn’t the density ofmaiden flight. However, after the end of the Second World War,1963) was set up as an auxiliary body of the Prime Minister’sJapan was prohibited by General Headquarters (office of the

Office. Later, the Laboratory became an auxiliary body of theSupreme Commander of the Allied Powers) from conducting any

Science and Technology Agency (now the Ministry of Education,

aeronautical research or manufacture.

Culture, Sports, Science, and Technology) when that Agency

It was in 1952 that aeronautical projects were allowed

was established. From its inception, the Laboratory was charged

to recommence. In order to fill in those seven blank years,

with the mission of accumulating the test facilities necessary fora system for aeronautical technological research had to beaeronautical research and of offering the use of these to related

quickly established. With the recommencement of research into

government organizations, universities, and the private sector, etc.

aeronautical technology, the Ministry of International Trade and

The Chofu Aerospace Center has developed and modified those test

Industry (now the Ministry of Economy, Trade and Industry), thefacilities in accordance with, and sometimes ahead of, the needs

Ministry of Transport (now the Ministry of Land, Infrastructure,of the time.

Transport, and Tourism), and the Defense Agency (now the
Ministry of Defense), etc., each asked for a research budget,
but much of the research and the facilities required were being■ Chofu Aerospace Center – started withwind tunnels

duplicated. Each wind tunnel requires a colossal amount of funds
and it was inefficient for such facilities to be provided at eachIn the seven years that research was not conducted in Japan,

2 m × 2 m transonic wind tunnel circa 1962.
The surrounding agricultural fields can be seen.

organization. In 1953 an Aeronautical Research Council was

the global aviation industry had moved from propeller-driven

established in the Scientific Technical Administration Committee

aircraft to jet aircraft. For this reason, the facility first planned atbuildings that there is today.” It is no exaggeration to say thatin the Prime Minister’s Office (now the Cabinet Office) and

Chofu was the transonic wind tunnel in which experiments on

Japan’s aeronautical technology prior to the end of the war

collaboration between the various ministries began on a future

the cruising state of jet aircraft could be conducted. Construction

was world class, with the Aeronautical Research Institute ataeronautical technology and research system.

started in 1956 and was completed four years later, in 1960.

the Tokyo Imperial University (present day University of Tokyo)

As a result of the findings of the Aeronautical Technology

One year after construction began on the transonic windsetting the world record in long distance non-stop flight and,Council established in 1954, the National Aeronautical Laboratory

tunnel, work started on a flutter wind tunnel as a structural testingin the year the war ended, the jet plane “Kikka” completing its(which became the National Aerospace Laboratory of Japan in

facility. Being smaller in scale than the transonic wind tunnel, the1920

First commercial passenger aircraft in Japan,
the “YS-11”. (Image: Japan Airlines Co., Ltd.)STOL experimental aircraft “Asuka” during flight testing, it is currently displayed at
Kakamigahara Aerospace Science Museum (left). The “Queen Air” was in service as a
research aircraft for half a century until it was decommissioned in 2011 (right).

flutter wind tunnel was completed in 1959, one year earlier thanon part of the Chofu Airport in 1961 and development support

of a half scale model of a tail wing section using carbon fiber

the transonic wind tunnel. The Council found that research into

for the YS-11 was provided by conducting load tests, fatigue

reinforced plastics (CFRP) started, as underlying technology

supersonic aircraft was also required, as a future technology, so atests, etc. The first research aircraft “Queen Air” was also bought

research for Asuka, and experimental facilities for evaluatingsupersonic wind tunnel was built. “These days you can’t hear any

around the same period.

composite materials were introduced.

sound or feel any vibration during wind tunnel tests, but in those

Between the latter half of the 1960s and through the 1970s,

Toda says “It may sound like self-aggrandizement, but Idays there were junior staff members who jumped up and criedaeroengine test facilities and flight simulators, etc., such as abelieve that the test facilities at the Chofu Aerospace Centerout ‘It’s an earthquake!’ during research presentations – that isground aeroengine test facility and an annular combustor test

and the research that was conducted there contributed to thehow much the glass doors shook.”, recalled Toda.

facility, were built for the development of Japan’s first high-development of aeronautical technology in Japan”. Even now as

The wind tunnels with their wide range of possible speeds,

bypass-ratio turbofan engine “FJR710”, and the short takeoff

part of JAXA, some of the test facilities at the Chofu Aerospacefrom low to supersonic and hypersonic speeds, have contributedand landing (STOL) experimental aircraft “Asuka”. In addition, theCenter are widely used by corporations and universities andgreatly to the development of aircraft in Japan. In particular, theQueen Air was modified to an inflight simulator*, flight of thecontribute to Japan’s increased industrial competitiveness as welltransonic wind tunnel has had a high level of operation and even

Asuka was simulated, and its flight test technology learned. NASA

as to improving aerospace technology.

today it is a struggle to allocate time to all the private sector,

pilots participated in the flight tests of the Asuka and, as former

university, and other users who apply.

Head Toda reminisces “Perhaps we were able to show them that

* Inflight simulator: A system whereby characteristics of a variety

Development of the first Japanese passenger aircraft, theJapan had reached the stage where our aviation industry couldof aircraft can be simulated, by flying via computer.

YS-11, began in earnest. An Aerodrome Branch was established

be useful to them”. It was also around this time that development

The Chofu Aerospace Center Premises
LEFT: Transonic wind tunnel during foundation
works, photographed in 1958. The general shape ofthe closed circuit wind tunnel is visible.

RIGHT: Panoramic view of the Aerodrome Branch, Chofu
Aerospace Center in 1975. The Chofu Airfield is top right.

A variety of testing and other facilities are built on two large
sites that includes the Chofu Aerospace Center, which occupies
approximately 120,000 m 2, and its Aerodrome Branch, which
occupies approximately 50,000 m2. However, these sites weren’t
always this large.
The site where the Chofu Aerospace Center is located was theCentral Aeronautical Laboratories prior to the war, then cameunder the jurisdiction of the former Ministry of Finance after
the war and was temporarily used as a transportation technology
laboratory. The site was selected because the availability of
power was good (the steel pylons for receiving electricity thatwere still there), and also because electricity could be supplied

relatively easily from the substation, the site was sufficiently
large, and Chofu Airport was nearby. Approximately 60,000 m2 of
the approximately 250,000 m2 of the former Central Aeronautical
Laboratories was acquired (by transfer from the former Ministryof Finance in October 1957) and construction of the transonicwind tunnel, etc., began. The surrounding agricultural fields were
subsequently bought, to ultimately create the current site.
In February 1961, the use of approximately 36,000 m2 of Chofu
Airport, under the management of the American armed forces at
the time, was permitted and the current Aerodrome Branch of the
Chofu Aerospace Center was created.

20
21

STRAIN GAuGeS

DeteCting strAin with A with A single OptiCAl Fiber

Optical Fiber
Sensor Research

OpTICAL FIBeR SeNSOR(AppROX. 0.15 MM DIA.)

Optical fiber sensor is linearly attached to the test wing surface
and protected by tape (not always necessary). Conventionalstrain gauges are shown extending to the left.

Understanding strain and the location of damage isimportant and necessary in aeronautical and spacecraft
technology and a variety of other fields. In conventionalstrain measurement, many gauges need to be attached to
BuNCHeD CABLeS FOR
CONVeNTIONAL STRAIN
GAuGe MeASuReMeNT
SySTeMthe target and these gauges can only measure the local
strains where they are attached .

OpTICAL FIBeRSeNSOR CABLe

At JAXA we are conducting research into optical fiber
sensors that will enable strain measurement using only asingle optical fiber.

Cables and optical fiber sensor for strain gauge measurment.
Optical fiber sensor can measure strain distribution with a single
optical fiber.

Optical Fibers As sensors

longitudinal direction of the optical fiber can be found by finding
the wavelength of the reflected light. Furthermore, strain canwing structure with high precision. We have also successfully

Optical fibers were originally developed for the communications

be measured at multiple points on the optical fiber if FBG are

detected strain and temperature simultaneously using one opticalfield, but a lot of research has been conducted since the 1970s

arranged at multiple locations therein.

fiber sensor.

laboratory stage, we can measure overall deformation of an entire

into the possible use of optical fiber properties in sensors.

Strain gauge sensors used in conventional strain measurement

A technology for writing the locations of periodic variation in

can measure strain only at the points where the gauges are

deformation with greater precision if used in wind tunnel tests.

the refractive index, called Fiber Bragg gratings (FBG), wasattached. Furthermore, a data transmission cable is needed for

In the near future these sensors might be used in static load

developed in the late 1980s and is now used in one type ofeach gauge which makes wiring extremely complicated. If thetesting during aircraft manufacture and are being considered

optical fiber sensor..

number of strain measurement points is to be increased, the samefor space applications such as the detection of leaks in liquid

number of cables need to be added. But with optical fiber sensors,hydrogen fuel tanks.

When light passes through an optical fiber that has an
FBG, the FBG functions as a filter whereby light of a specificstrain can be measured at many points in a line, by wiring only

wavelength is reflected where the FBG is located and all otherone optical fiber.

Optical fiber sensors have the capacity to measure model

Hirotaka Igawa, Associate Senior Researcher in the
Struc tures Research Group, explains the dream: “Ourlight is transmitted. The fiber expands and contracts with

Optical fiber sensors are already used in the civil engineering,

research aims at finding, in real time, strains and damage

the application of force and the wavelength of the reflected

construction and energy sectors – for example, to measure theto the wings and fuselage of aircraft, by using opticallight changes. Strain and temperature change relative to thetemperature inside an oil field well, during drilling. They are also

fiber sensors. This is for more effective “structural healtharranged along pipelines to detect damage or ruptures.

monitoring.” If we can do that, we will reduce accidents anddramatically reduce the amount of maintenance required. If

DiFFerenCe between Multi-pOint sensing AnD
DistributiOn sensing using OFDr
MuLTI-pOINT SeNSING

DISTRIBuTION SeNSINGOne Optical Fiber to Ascertain
Aircraft Conditions

we add actuator technology and improve structural functionality,
we can provide the capacity to further improve aircraft
performance during flight, beyond the limits of the physical

JAXA is researching the distributed strain measurement system
MeASuReMeNT ReSuLTS
pReDICTION FROM
MeASuReMeNT ReSuLTS

based on Optical Frequency Domain Reflectometry (OFDR)
technology, whereby periodic change in the intensity of light

ACTuAL STRAIN

generated by the interference between reflected light from a
position reference mirror and reflected light from an FBG sensor

MeASuReMeNT VALue

MeASuReMeNT VALue

Even with one optical fiber sensor, an entire detection
area can be measured in detail using distribution
sensing thereby enabling precise measurement.

22
12

properties of the materials and structural characteristics.”

are examined and relative measurement positions are identified.
The concept of OFDR was already known, but at JAXA we haveachieved spatial resolution of no more than 1 mm, by using
our own data processing algorithm and, although still at theHirotaka Igawa
Associate Senior Researcher
Smart Structures Section
Structures Research GroupMeeting with IFAR Members in Berlin
The Latest Report on International Collaboration by
JAXA Institute of Aeronautical Technology
JAXA actively engages in international collaborative activities to further hone the technologies at JAXA and to eventually contribute backto society. For this purpose, JAXA participates in joint research with international partners, such as overseas public research institutions,
universities, and corporations. To maintain and foster cooperative relationships with overseas aeronautical agencies, a series of meetings
were held that coincided with the 2014 Berlin Air Show (20-25 May) to which many of members from the International Forum for Aviation
Research (IFAR), including JAXA as Vice Chair, were in attendance. Top-level meetings with NASA and the German Aerospace Centre (DLR),
who are important cooperative partners for JAXA among the IFAR members, were also held. Here is a summary the successful outcomes of
those meetings as the latest highlight of international collaboration undertaken by JAXA’s Institute of Aeronautical Technology.

Atsuko Nakasone

Program Management andIntegration Department
Institute of Aeronautical
Technology■ Cooperation in AtM Field under iFAr
The International Forum for Aviation Research (IFAR) is the world’s only aviation research establishment network comprising public
aeronautical research and development agencies on a voluntary, non-binding basis. IFAR aims to connect research organizations worldwide,
to enable the exchange of information and communication on aviation research activities, and to develop among its members a sharedunderstanding of the challenges faced by the global aviation research community.
Eleven of the 24 member agencies attended the Berlin Air Show and they were appreciative of the warm hospitality extended by the
DLR. IFAR members held meetings to discuss collaboration progress and IFAR’s operational policies. One of the major achievements wasan undertaking to begin collaborating in the field of air traffic management (ATM). This is IFAR’s second scientific and technical initiative,
following its first joint research initiative to study the impact of alternative aviation fuels on the environment. The first meeting by agencies
involved in the ATM Working Group was held in Berlin with the participation of JAXA ATM researchers, and each agency expressed an
anticipation of positive results from IFAR’s involvement. Air transport is facing the challenges raised from an expected increase in global
air traffic volumes, especially in the Asia-Pacific region. A lot of research and development has already been conducted, and IFAR hopes toleverage these efforts through their global network and to contribute to a faster, more efficient resolution of global air traffic problems.

Attendees of the meeting pose in frontof the Brandenburg Gate. JAXA wasappointed Vice Chair of IFAR in 2013and has been playing a leading rolein IFAR, together with the Chair, NASA.

■ Agreement with nAsA on Mutual Cooperation in the field of AtM
An agreement was signed at a meeting with NASA for research collaboration in the ATM field. NASA's Aeronautics Research Mission
Directorate is the most important and closest research partner of the Institute of Aeronautical Technology at JAXA. Based on past
discussions which pointed out the needs of promoting more strategic research collaboration in the environment and safety fields, anagreement was reached to begin cooperation in the ATM field. Over the next five years, NASA and JAXA will mutually benefit from thiscooperation based on JAXA’s noise reduction operation technology, NASA’s airport schedule management technology, and JAXA/NASAtechnology for aircraft operation during disasters.
With the start of this new collaboration, NASA-JAXA can count four joint research initiatives in the field of aeronautics. NASA and JAXA
confirmed their mutual cooperation in these collaborative works and also in relation to the operation of IFAR, given that NASA is the Chair
and JAXA is the Vice Chair.

■ Deepening ties with Dlr
JAXA’s Institute of Aeronautical Technology has built a long-term cooperative relationship with DLR in Germany, one of our important
overseas partners. A variety of joint research projects have been conducted with DLR, including those under a tri-lateral joint research

Senior management in the
aeronautical field from DLR and JAXA.

framework established in 2001, including the French aerospace research agency ONERA. The senior management of the respective
aeronautical departments within JAXA and DLR met in Berlin and resolved to strategically deepen their cooperative relationship.
Whilst in Germany, JAXA’s delegation members paid a courtesy visit to DLR Stuttgart, where a JAXA researcher is undertaking overseas
training (from 2013 to 2014) and conducting research into composite materials. In the past, DLR Stuttgart has hosted other researchers
from JAXA in the field of fuel cells and electric motors. These visiting researchers successfully established close working relationships with
their DLR counterparts, which also helps both DLR and JAXA to foster unique and deeper ties at the organizational level.
Personnel exchanges such as this promotes a basis for mutual understanding and trust between research laboratories at both anorganizational and personal level. JAXA believes that in the future this will add to an already favorable environment for mutually beneficial
R&D collaboration with DLR.

DLR electric-powered demonstration
aircraft (DLR-H2 Antares)

There is severe international competition in the field of aircraft technology development. However, this also requires international cooperation if we are
to raise the level of technology in non competitive areas, address environmental and safety issues and establish global standards. The JAXA Institute of
Aeronautical Research will continue to promote its trustful relationships with overseas partners and promote strategic international cooperation.
23
13

ying D-NET
ter Operation" appl
op
lic
He
ef
eli
T
r-r
NE
Dste
sa
hting andin Development ofr Fire-fighting and Di
ement System for Fire-fig
Progress Continues
agement System foanMtheir "Centralized Manag
of
ed
ion
liz
rat
tra
ope
en
an
"C
g
beg
ns
FDMA started usin
airs and Communicatio
eloped by JAXA.
Ministry of Internal Affthat there wereg Network (D-NET) dev

arrin
Agency of the
however, it became cle
Aircraft Information Sha
Disaster Managementwith the Disaster Relief
rations in disaster areas;
ope
lied
app
cue
is
In April 2014, the Fire and
res
ich
in
wh
ed
pat
tem
tici
of aircraft parr Operation," a new sys
as aircraft
nami, a large number
Disaster-relief Helicopte
ide reports—as wellan Ear thquake and Tsu
Jap
t
Eas
at
Gre
the
of
h as flooding and landsl
sucnarters.
atio
dqu
orm
hea
inf
In the aftermath
ef
t.
er
reli
raf
ast
erground-based disast
efficient use of those aircough the sharing of dis
and
st
thr
le
mo
tem
sib
the
sys
g
pos
s
the
ut
kin
h
ion
ma
wit
rat
h
problems wit
more efficient ope
all aircraft equipped
detailed information abo
which makes safer andto share and monitor
completed"—among
s
gy
ed/
ter
olo
ign
cen
hn
in
ass
n
tec
MA
on
a
atio
FD
issi
is
orm
ws
"m
ET
D-N
h sharing of inf
as "in transit" andement system allo
ed to facilitate the smoot
ional information suchnew operation manag
ect
rat
the
exp
ope
ich
is
rs,
wh
pte
and
s
tem
a
ico
ard
sys
dat
hel
nd
n
all
new
sta
atio
a
loc
ation of
In addition, thethe D-NET dat
cking of position inform
ed to each helicopters.
ause it is built based onh other
On top of real-time traprogress of tasks assign
rescue operations, bec
m
and
for
tus
per
therefore compatible wit
sta
o
al
als
and
ion
A
ion
rat
FDM
rat
ope
ope
the
as
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ll
ef
we
tha
reli
er
as
er
as
ast
oth
are
dis
ups
n
nt
gro
disaster-strickefor safe and efficie
ltiple disaster suppor tment for aircraft.
centers on the grounde disasters in which mu
icient operational environ
h aircraft and relevant
eff
re
wit
mo
the event of large-scal
red
and
sha
er
be
saf
uld
a
sho
icipated to create
information thater organizations. It is ant
summarizes all necessary
currently in use by oth
tem
sys
ent
em
nag
ma
aircraft operationof pro du ctsrd to pro mo te the use
JAX A ha s wo rke d hatoort increase thedata standard in an eff
based on the D-NET
ation via D-NET. In
ormable of sharing inf
cap
t
raf
airc
of
er
mb
nu
an marketing their
ION CORPORATION beg
2013, NAVICOM AVIAT
de Web Sentinel,”
nagement system “Latitu
helicopter operation ma
one-quarter the
ET data standards–and
newly adopted with D-N, in addition to
tem
sys
s
ET devices. With thi
weight of existing D-N
FDMA).
nsmitted through(image provided by therational data can be traen of the new systemht) to
scre
y
(rig
the
pla
g
ner
Dis
sio
win
location data, simple ope
mis
allo
,
als
hio Ois hi, FDM A Com
keypad to ground termin
Cou rte sy vis it by Tos
this system via a numeric
t).
(lef
ent
sid
Pre
.
Naoki Okumura, JAXA
information to be shared

Assessing the Turbulence Information System "ALWIN"at Narita Airport

System with
Testing a Next-Generation Landing Guidance
ENRI at New Ishigaki Airport

and the Electronic Navigation Research
From March 19 through March 30, 2014, JAXA
the next-generation landing guidanceofInstitute (ENRI) conducted an assessment test
are being determined.
rds
standalationasystem "GAST-D," for which internused at many airpor ts to enable
are
(ILS)
s
systemg
landinCurrently, instrument
condi tions due to bad weather. By
aircra ft to land safely even in low-v isibili ty
ement onboard satellite navigation,
suppl
transmitting GPS correc tion messages toe the same function as ILS with
provid)(GBASsground-based augmentation system
ted to allow for curved and flexible
equivalent or higher precision. GBAS is also expec
approaches that cannot be realized with ILS.
I GBAS (GAST-D) ground facilit y
ENRI developed a prototype for a Category-II
severe weather conditions and
more
in
even
ft
capable of safely guiding an aircra
ments were performed by JAXA with the
installed it at New Ishigaki Airpor t. Flight experi
s of ionospheric plasma bubbles* on
research aircraf t "Hisho" to investigate the effectch aircraft "Yotsuba" to evaluate
researthesatellite navigation, as well as by ENRI with.
systemD
GASTthe performance of the installed*Plasma bubble: an ionosphericdisturbance where the plasma
density is depleted; occurs at low
latitudes around the magnetic
equator in the night in equinox
seaso ns in the Asian secto r.
GPS signals that pass throughplasm a bubb les expe rienc e
rapid fluctuations in amplitude
and phase , which may resultin malfunctio n of GPS- basednavigation systems.

"Hisho" (right) and "Yotsuba" (left) waiting forof a flight test at New Ishigaki Airpor t

FLIGHT PATH
PATH No.5/6
No.3/4JAXA Aeronautics
Aeronautics Magazine
Magazine
October 2014

the start

During the period of Ma
rch 3 to May 9, 2014, JAX
A and the Japan Meteo(JMA) conducted an eva
rological Agency
luation of the new turbul
ence information system
Low-level Windshear Info
ALWIN (Airport
rmatioN) at Narita Interna
tional Airpor t with theairline companies JAL andcooperation of
ANA.
ALWIN is a system that uses airport weather
Doppler lidar already ins
JMA to implement par ttalled by theof the technology of the"Low-Level Turbulence(LOTAS)*1 that JAXA has
Ad
visory System"
been developing. In ord
er to allow aircraf t to saf
airport, ALWIN provides
ely land at anreal-time information to
onboard pilots and dis
airport on the status ofpatchers at thewinds (direction, speed,win
d shear, turbulence, etc.)
paths of their aircraft. For
in the landing
this evaluation, the protot
ype ALWIN system wasinformation on winds aro
used to provide
und the airport and in lan
ding paths to dispatchers
to pilots via a text-based
via internet anddatalink system known
as ACARS installed in theMoving for ward, the util
cockpits.
ity of the system will be
improved by reflecting
comments collected thr
evaluationough questionnaires andmeetings with pilots andused ALWIN. In addition,
dispatchers who
flight data from the aircraft that actually landed
assess the effectivenesswill be used toof ALWIN by comparingthat wind data recorded
the wind information pro
on the aircraft tovided by ALWIN.
*1 LOTAS: a system which uses weather observ
ation sensors (radar/lid
airport to detect the lowar) installed at an-altitude turbulences reg
ardless of weather andairport flight dispatchers
provide pilots andwith information on tur
bulences, current and ten
future.
minutes in the*2 Airpor t weather Do
ppler lidar: adev ice that me asures
the wind at
low altitudes under non-precipitation
conditions by using las
er beams todetect the movement ofaerosols (fineALWIN wind informati
par ticles) in the atmosp
on (wind profiles)
here; currently
ALW IN wind info rma tion
installed at Japanese ma
dis
pla
yed
on airc raf t coc kpi t
jor airports instruments (image provided by Jap
such as Narita Internationan Airlines Co., Ltd.)al Airpor t.

Institute
Aeronautical
Technology,
Japan
Aerospace
Exploration
AgencyTechnology(JAXA)
Publishing organization: The
JAXAof(Japan
Aerospace
Exploration
Agency)Instituteof Aeronautical
Masatoshi
Harigae,Director,
ProgramManagement
andandIntegration
Department,
Instituteof Aeronautical
Technology
Publisher: Takeshi
Ohnuki,
Directorof theProgramManagement
Integration
Departmentof the Instituteof Aeronautical
Technology
7-44-1 Jindaiji Higashi-machi, Chofu-shi, Tokyo 182-8522
TEL: +81-50-3362-8036
Website: http://www.aero.jaxa.jp/
http://www.aero.jaxa.jp/
Website:[All rights
Parties
interested
in duplicatingor reprinting
FLIGHT PATH,
the JAXA
shouldcontact theInstituteof Aeronautical
Technology.
[Allrightsreserved]
reserved]
Parties
interested
in duplicatingor reprinting
FLIGHT
PATH,Aeronautics
the JAXA Magazine,
Aeronautics
Magazine,shouldcontact
the Instituteof Aeronautical Technology.

t design
rrangemen logy
a
e
ic
v
e
d
s
no
aid
ment dataization tech
PIV measure sts to develop optim
ing ofel te
r*1 on the weWind tunn
rtex generato
e design stagsuch as a vos
sts in thent of device
ind tunnel tero dy namic
The arrangems repeated w
ire
the be st ae
qu
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re
el
lly
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ua
to
us
t
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en
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ai
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obtained by
to de te rmin
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su
ea
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charactenduct resear
e of high-denen able to co
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ak
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XA
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JA
By
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or
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to do soent on metho
teristics and
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and developm
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ansonic
devices to ha
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2m × 2m tr
be
XA
ith
JA
w
e
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us
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of
te
ai
d
perio
conducces in therement tests
clear diff eren
tions
ed
ria
rv
va
In PIV measu
se
w
ob
, we
the airflo
in June 2014
eed
tors, as well as
oc
ra
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ne
to
ge
ex
an
wind tunnelrtplis data, we
d without vo
th
an
ng
ith
si
U
w
.
d
rs
te
generaces.
the generatoof these devi
rangement of
arrangement
eiv
due to the arct
fercrafteflywing of an ai
derive a hightached to thewith R&D to
at
ace.
ne
rf
va
su
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g
oi
tin
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w of the ai
r is a projec
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e
ra
th
ne
l
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ex
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*1 A vort
tream and toseeding tracer
rtex in the airs
fluid flow byoftyci
to cause a vo
lo
with
ve
e
n as recorded
easuring thof their motio
chnique for m
te
es
a
ag
is
im
V
g
PI
in
*2
)
analyzthe flow andr. (See page 15
particles intosuch as a lase
ce
ur
so
ht
lig
ma
lts
illumination fro
rement resu
city measu
the
m
fro
ce
Air flow velo
in sequen(Color coded
slowestdown to thefastest speed
reen.), and yellow-g
in red, yellow
or texvo
re a re n
When thew arealorf
airs, the slow
to
ra
rs
ne
ge
rato
yellow
With vo rtex geneen colored inthat can be se
image)
reen (bottom
and yellow-g
vortexanaller whebecomes sm
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ag
im
ed (topgenerator is us
Witho ut vo rtex

Noise measurements taken around
Narita Airport
With the coo

peration of Narita Air
port and the surrou
we measured aircranding communities,
ft noise there from
1 to 11 July 2014. Me
were first taken in No
asurements
vember 2013, thenagain in January 2014
2014, and so this wa
and Marchs the fourth time tha
t measurements we
The resulting noise dare performed.
ta obtained therefore
reflected the weather
in each of the four sea
conditions
sons.
As air traffic is expect
ed to increase in the
future, noise mitigati
a critical factor thaton is
we should address.
In order to limit the
impact, irrespective
range of noiseof how much air traffic volume increases
been researching low, JAXA has
noise operation technology to predict how
conditions aff ec t theweather
spread of noise –to optimize aircraft
paths with the aim
approachof containing ground level noise to cu
This research is pa
rrent levels.
rt of the Distributedand Revolutionarily
traffic Management
Efficient AirSystem (DREAMS) pro
ject. JAXA will contin
the measurement res
ue to use
ults taken to dateto fur ther its resea
noise prediction morch utilizingdels that take into
account the influenc
conditions in the pro
e of weather
pagation of noise.

Noise measurements being taken during

landinggene rato rs

Second test of D-SEND#2 suspendedof Non-symmetricallyphase of the Drop test for Simplified Evaluation
period, the second test planned for the second
Due to bad weather conditions during the test
en’s Esrange Space Center has been suspended .
Distributed sonic boom project (D-SEND#2) at Swedtest airplane deviated from16, 2013, after separating from the balloon, theIn the first test that was performed on August
measure the sonic boom
toleof the measurement point, making it not possib
the planned flight path at about 12 km shortteam which has been
easurenterm
n/cou
igatioed. JAXA has established an invest
with the flight conditions that had been assumsures.
working to clarify the cause and to study countermea
at the site in mid-June
began
test
d
secon
the
for
work
Preparatory
tions to come together
condi
2014. We had been waiting for favorable test
ed the ground weather,includs
Factor.
since the beginning of the test period
spheric balloon. When
stratotheoftory
trajected
surface winds, and the predic
26, preparations began for
conditions were finally ready on August 23 andmidway on each day so
ned
performing the test but weather conditions worse
test.
the
reluctantly a decision was made to abort
amining the test plan for
In light of this current situation, JAXA is re-ex
D-SEND#2 test rehearsal
Inspection of the test airplane
D-SEND#2.