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Air Systems Research Center

Outline

The Air Systems Research Center conducts research, test and evaluation on aircraft, related components and missiles.

Aircraft Research Division

Research on system integration of aircraft and component technology for aircraft, aircraft-related equipment and missiles.

Engine Research Division

Research on system integration of engine and component technology for aircraft and missiles.

Missile Research Division

Research on system integration of missiles and component technology for missiles.

Tsuchiura Branch

Environmental test and combustion test of rocket motors.

Niijima Branch

Service for firing test of missiles.

Researches for Future Fighter

Concept of Future Fighter

 ※“Future Fighter R&D Vision”

Network Shooting “Integrated Fire Control for Fighters (IFCF)”

“Network shooting” will be a game changer for the future fighter. “Integrated Fire Control for Fighter (IFCF)” system is to make network shooting practicable.
 Network shooting is a concept of cooperative missile shooting which is realized by network communication between fighters. In the process of missile shooting, search and track of targets, release of missile, and guidance of missile are shared among multiple platforms. With this capability, air-to-air combat beyond visual range is expected to become highly effective, since each of fighter can be free from positional and directional constraints by switching or by sharing missile shooting process among a fighter formation. IFCF system consists of high-speed intra-formation datalink subsystem, fire control computer and software.

Cockpit view of the IFCF simulator

The prototype of IFCF software has been tested and modified through the pilot-in-the-loop simulations, which demonstrate the effectiveness of network shooting under various situations, such as air defense operations in a quantitatively disadvantageous manner.
 Prototyping of intra-formation datalink subsystem is now undergoing, and will be verified in the flight test.

Superior Stealth

Weapons bay
Stealth (serpentine) intake duct

Stealth is a key technology for the future fighter to acquire low-probability-intercept capability.
 The internal weapon bay system and the stealth intake duct are effective measures to reduce radar reflection from externally carried weapons and engine inlet, respectively.
 Other technologies, the lightweight airframe structure and the electric actuation system are also required to realize the stealth fighter.
 Air Systems Research Center (ASRC) is working to establish those technologies through the research, prototyping and tests.

Internal Weapon Bay System

The safety of weapon release sequence should be secured under any flight conditions including high-speed and accelerated maneuvers.
 The complicated aerodynamic flow field around the weapon bay and missiles was scrutinized by wind-tunnel tests and CFD in the early phase of the research. The following is the ground-based prototype of an internal weapon bay system with an air-to-air missile launcher, designed and manufactured to prove the effectiveness of the system.
 Safe and quick sequences of door-open, weapon-separation, and door-close were successfully demonstrated through ground tests under various simulated flight conditions.

Weapon release sequence of the full-scale internal weapons bay system

Stealth (Serpentine) Intake Duct

Stealth Intake Duct is a serpentine intake duct to make an engine inlet invisible from the anterior view, which suppresses Radar reflection. However, it causes the distortion of the air flow due to vortices and flow separation, resulted in unstable engine operation.

The air flow control is the methodology to improve the aerodynamic characteristics with maintaining the stealth capability. Aerodynamic data acquired through wind-tunnel tests were reflected in the design of the stealth intake duct and the accuracy assurance of the CFD estimation.
 The wind-tunnel model of the stealth intake duct including the boundary layer control system for the air flow control was tested at the tri-sonic wind-tunnel of Chitose Test Center of ATLA and demonstrated the low-level of air flow distortion.

Overview of Wind Tunnel Model
Wind Tunnel Model in Tri-sonic Wind Tunnel

Lightweight Airframe Structure

The internal weapons bay system and the stealth intake ducts, applied to the stealth fighter, increase structural weight because of large fuselage volume. The integrated bonded structure and heat-shield technology are introduced to reduce structural weight.
 The integrated bonded structure is a unified fastener-less structure which can be realized by prominent composite materials and bonding technologies. Heat-shield materials can shield heat from engines to airframe structure, which can increase usage of lightweight materials. Efficient and accurate structural analysis techniques are required to apply those technologies.

In the research on lightweight airframe structure, those technologies are being verified in several phases. In the first phase, the test article of the fuel tank sections was fabricated and subsequently tested by loading the simulated fuel pressure. Test results were used to validate the bonding technology and the analytical strength estimation. The full-scale mid-fuselage is now being tested under various simulated in-flight loading conditions.

Electric Actuation System

The aircraft surface design of stealthy fighter is more demanding than that of conventional one. In the design, a lot of attention is paid for the size and the position of access panels. Such design parameters depend in large part on maintainability regarding hydrostatic equipment inside body. A promising solution is that replacing conventional hydrostatic actuator with electric one. This technology will lead tremendous advantages for stealth, maintainability and even survivability.
 ASRC has been conducted the study of electric actuation system. In the study, Electro-Hydrostatic Actuator (EHA) and Electro-Mechanical Actuator (EMA) attaining reduced size and weight with careful consideration of environmental stress and electromagnetic compatibility which covers fighter aircraft flight performance have been investigated. The design and prototyping of the electric actuation system have been conducted. Ground test will be carried out.

High-Power Slim Engine “XF9-1 Turbofan Engine for Fighter Aircraft”

To realize the stealth, high-altitude, and high-speed combat capability of a future fighter, ASRC is actively carrying out research on a fighter engine that achieves both "slimness" and "high-power thrust" simultaneously. Following the research of low-pressure components and of core engine system employing examined core engine components, "XF9-1", a prototype of high-power and slim fighter engine was successfully manufactured. ASRC is now evaluating the performance of "XF9-1" through engine run testing. ASRC drives achieving cutting-edge technologies for an engine that can be installed in the future fighter.

Ground testing on the XF9-1

The XF9-1 has completed manufacturing in June 2018 and started testing from July 2018 to demonstrate design performance. In early August, ASRC successfully demonstrated the targeted maximum thrust of the 15 ton force. The technical demonstration by engine tests is planned until March 2020.

XF9-1 installed in IHI engine test cell

Technical Evaluation of Core Engine

The core engine, which is the very "heart" of the state-of-the-art engine, has been tested at ATF of Chitose Test Center of ATLA until March 2020, including the performance demonstration at flight condition of the engine. Acquired data were actively reflected in the design and manufacturing of the XF9-1.

Core engine at Chitose Test Center ATF

ATF: Altitude Test Facility

Technologies Underpinning the XF9-1

Realization of High-Power Slim Engine

  • High-pressure ratio fan achieving high specific mass flow rate and high efficiency.
  • Core engine demonstrating successful operation at high combustion temperature of 1,800℃.
  • Highly-loaded counter-rotating low-pressure turbine driving high-pressure ratio fan.

Engine inlet of the XF9-1 is 30% smaller than that of conventional engine applied in 4th generation fighter, JASDF F-2.
JASDF:Japan Air Self-Defense Force

World Leading high Temperature Technology

Low Cycle Fatigue (LCF) rig test for high-pressure turbine blade

  • Weight reduction of the compressor by shortening the axial length.
  • Increased combustor outlet temperature, applied with an efficient cooling structure.
  • Application of cutting-edge material to the high-pressure turbine, enabling the world-leading high temperature.

Research on Thrust Vectoring Nozzle

To realize aggressive maneuver and high stealth capability of a future fighter aircraft, ASRC is engaged in research on Thrust Vectoring Nozzle (TVN) technology. The TVN technology makes it possible to control the attitude of the aircraft by deflecting the exhaust jet, i.e. vectoring the engine thrust, which effectively supports the function of the conventional aerodynamic control surface.

Sketch of the operation concept showing a comparison of conventional aircraft and aircraft with TVN Technology

In this research, ASRC is prototyping the TVN which can change the direction of the engine exhaust jet by up to 20 degrees from engine axial direction in all around. ASRC plans to mount the prototyped TVN on XF9-1 and evaluate its performance by ground engine tests.

Researches Related to UAV

R&D Vision of Future Unmanned Equipment: Focusing on Unmanned Aerial Vehicle


”R&D Vision of Future Unmanned Equipment”

OPV System Integration of Small IR Sensor on OPV for BMD Warning

A warning mission for BMD is operated in a monotonous and danger situation for a long time, which is quite severe for human to carry out. It is expected that UAVs with an IR sensor for the detection of the ballistic missile conduct such cruel missions.
 Not only an early detection technology with high performance IR sensor, it is required to establish continuous surveillance technology, which allows autonomous flight-path generation under various weather condition and unmanned operation such as collision avoidance and autonomous take off/landing.
 As shown in “Unmanned Air Vehicles Technology R&D Roadmap,” one of the effective methodology for evaluation of these technologies is OPV, an aircraft customized from manned one, which allows to choose between manned and unmanned flight, as necessary.

Flight Test Setup

In this research, technologies such as autonomous flight-path generation considering weather condition are demonstrated in step-by-step through “Physical-Simulation Test.” Following some demonstrations, a KM-2D type aircraft is customized as an OPV demonstrator with an IR sensor and equipment for demonstrating autonomous flight. The maiden flight was in October, 2018.
 From October 2019 to November 2019, ASRC conducted the flight tests of this demonstrator aircraft for the verification of the continuous surveillance technology, in Taiki Multi-Purpose Aerospace Park and surrounding airspace, Hokkaido.

Guided weapons related research

Missile Guidance Technology for High Altitude & Speed Target

In order to exclude threats, such as ballistic missiles and supersonic cruise missiles efficiently, it is indispensable to have ability to defeat missile in a high altitude domain. Intercepting high speed target requires ability to guide interceptor in a highly accurate quality. However, aerodynamic steering cannot be performed in high altitude domain since it has very thin air density. This fact increased the need of missile body control technology which does not depend on aerodynamic steering.

This research is aimed to realize missile body control technology which combines two different forces. One is Side Thruster which generates hot gas toward orthogonal direction of missile. Another one is Thrust Vector Control, which deviate direction of rocket motor thrust by the small valve called jet tab. Combination of these two forces are expected to realize missile intercept in a high altitude domain.

Predictive Optimal Guidance Technology

Recent fighters (or bombers) tend to obtain the stealth capability in order not to be detected by the radar of enemy missile or fighter. In case of detecting or tracking the stealth fighter (target) the range for guidance between missile and target is getting shorter and shorter. It should turn harder and harder for missile to kill the maneuvering target for missile evasion.
 This new technology enables the missile to attain effective guidance by reputation of both the application of model predictive control and the closing simulation with the estimated target maneuver based on the observed target information, which could finally produce the efficient missile guidance path against the maneuvering stealth fighter.

Image-guidance technology for low contrast target

Conventional optical seekers with detection algorithm capturing the temperature difference between target and background, have a difficulty in detecting targets from low contrast scene in temperature (e.g. warship moored to a wharf or tactical vehicle parked on the ground).
 In this research, ASRC committed to construct a novel image processing algorithm for the future optical seeker, which enables to detect and identify “low contrast target” from the background with temperature nearly equal to the target. Furthermore, ASRC research the evaluation method for the algorithm.
ASRC is working on the research to achieve these algorithm applying feature amount detection technique and image matching technique with database by means of AI (Artificial Intelligence).

Future Fire Control Radar Technology

Recently, the aerial attack on a ground object tends to be conducted by multiple threats simultaneously. In order to improve the capability of fire control radar against aerial multiple threats, such as stealth fighters / bombers, high-speed air-to-surface missiles, low-altitude cruise missiles, etc., a research on radar resource control according to the characteristics of threats is conducted.

Millimeter Wave Fire Control Radar Technology

In order to defeat approaching landing boats, combat vehicles and others in near field, Fire Control System (FCS) using optical sensor could be ordinarily applied. On the other hand, in smoke screen or foggy condition, such FCS is apt to be restricted operationally. Compared with optical sensors, a millimeter wave radar has much more capability to detect targets even in smoke screen or foggy condition. Therefore, a research on millimeter wave fire control radar is conducted to dealing with seaborne, ground and aerial threats.

Jet-fueled Dual-mode Scramjet Engine

Scramjet engine is a game-changing technology since this engine enables a vehicle to cruise hypersonically (Mach 5 or higher) at such a high altitude where aerodynamic control surface performance of conventional interceptors declines.

Compared with hydrogen, a jet-fuel which is a kind of hydrocarbon fuel offers such advantages as high volumetric energy density, low cost, and relative simplicity of operation for tactical applications.
 Employing ramjet/scramjet dual-mode operation, wide range of flight altitude and speed can be covered by single engine and then that enables us to design a simple-structured and compact hypersonic flight vehicle.

Concept of a hypersonic vehicle

ASRC and Japan Aerospace Exploration Agency (JAXA) are jointly investigating combustion performance of a jet-fueled dual-mode scramjet engine and cooling ability of a jet fuel for a regenerative cooling system. A model combustor that simulated the main portion of the scramjet engine and a flow path equipped to the engine walls were designed in this research. The model combustor well-characterized through firing tests using a blow-down-type wind-tunnel facility with direct-connect configuration. Furthermore, heat transfer coefficient of the fuel was acquired using a cooling channel. Based on these data, ASRC has been attempting research on a flight-like scramjet engine system.

Design concept of model combustor
Experimental setup of Firing Tests at JAXA Kakuda Space Center
Combustion behavior at simulated acceleration phase condition (ramjet mode)
Combustion behavior at simulated hypersonic cruising phase condition (scramjet mode)

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