This paper presents basic aerodynamics and stall characteristics of the high-lift configuration aircraft model JSM (JAXA Standard Model). During research process of developing high-lift system design method, wind tunnel testing at JAXA 6.5m by 5.5m low-speed wind tunnel and Navier-Stokes computation on unstructured hybrid mesh were performed for a realistic configuration aircraft model equipped with high-lift devices, fuselage, nacelle-pylon, slat tracks and Flap Track Fairings (FTF), which was assumed 100 passenger class modern commercial transport aircraft. The testing and the computation aimed to understand flow physics and then to obtain some guidelines for designing a high performance high-lift system. As a result of the testing, Reynolds number effects within linear region and stall region were observed. Analysis of static pressure distribution and flow visualization gave the knowledge to understand the aerodynamic performance. CFD could capture the whole characteristics of basic aerodynamics and clarify flow mechanism which governs stall characteristics even for complicated geometry and its flow field. This collaborative work between wind tunnel testing and CFD is advantageous for improving or has improved the aerodynamic performance.
Pitch controllability of an airplane is very important for longitudinal flying qualities, therefore, much research has been conducted. However, it has not been clarified why pitch handling qualities degrades in the low speed, e.g. take-off and landing flight phases. On this topic, this paper investigates the effect of several parameters of the short-period mode and phugoid mode using a flight simulator. The results show the following conclusions: The difference between the initial phase angles in two modal components in the pitch attitude response to elevator step input plays the most important role in the pitch handling qualities among modal parameters; and the difference of the two modal natural frequencies has small effect on the pitch controllability even when flight speed decreases.
The University of Tokyo, Kobe University and Vienna University of Technology conducted a set of experiments including large membrane “Furoshiki Satellite” extension and active phased array antenna operation in January 2006, by using ISAS/JAXA sounding rocket S-310-36, one of their purposes was to demonstrate a cold gasjet propulsion system for microsatellites which makes use of effective COTS. A series of verification tests concerning the propulsion were conducted on ground before the launch, and it resulted in confirmation of 70 seconds of specific impulse at 250mN of thrust with little leakage for 4 months and good resistance to vibration and shock environment of the launcher. Although specific impulse of the propulsion in orbit was not determined, the propulsion system worked very well and we acquired pressure history of its tank, and established the basis of moderate-priced propulsion system for microsatellites and are ready to salute the coming era of microsatellites equipped with propulsion.
Electrostatic discharge (ESD) occurs on the solar array due to space plasma interaction. It is considered that solar cell suffers degradation of electric performance, once ESD occurs at the solar cell edge. In order to study the degradation of solar cell electrical performance, we performed ESD tests on Si solar cell in a vacuum chamber. After the ESD tests the solar cell maximum power decreased. We found the damage on surface electrode in the vicinity of ESD spot. Infrared emission due to current leak was found at the spot. The solar cell degraded due to the leak resistance produced by ESD.
An experimental study was performed to investigate the flame-holding of hydrogen jet injected into supersonic cross-flow interacting with an incident shock wave. Pre-burned rich hydrogen or air was injected in supersonic airflow at Mach 2.5. The injection pressure was 1.2MPa or 1.6MPa. The deflection angle of the shock generator was 10 deg. Velocity profiles near the wall and those of recirculation zones around the injection slot could successfully be measured using newly-devised PTV method in this study. The velocity profiles showed that re-attachment point of separation downstream of the injection slot moves downstream when the incident shock wave is introduced to downstream of the injection slot. The re-attachment point with the incident shock wave in case of the injection pressure of 1.6MPa was not so different from that of 1.2MPa. However, extinction limit in case of the injection pressure of 1.6MPa extended than that of 1.2MPa.
An ion engine with 10,000sec-class high specific impulse is expected as primary propulsion for interplanetary space mission with extremely high delta-V, and needs high voltage for ion acceleration over 10kV. The microwave discharge ion source without solid electrodes can supply sophisticated technologies and simple composition on electrical isolation for such a high voltage. New electro-static grid made of carbon-carbon composite material was fabricated based on the numerical simulation of “igx” code. The “μ10HIsp” ion engine combining the ECR ion source, microwave discharge neutralizer, DC blocks, propellant isolators, carbon-carbon composite grid and so on generated successfully a plasma beam with 10,000sec specific impulse using 15kV acceleration voltage.