著者

國中 均 西山 和孝 清水 幸夫 都木 恭一郎 川口 淳一郎 上杉 邦憲

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.52, no.602, pp.129-134, 2004 (Released:2004-05-20)

参考文献数

11

被引用文献数

5 6

---

The microwave discharge ion engine generates plasmas of the main ion source as well as the neutralizer using 4GHz microwave without discharge electrodes and hollow cathodes, so that long life and durability against oxygen and air are expected. MUSES-C “HAYABUSA” spacecraft installing four microwave discharge ion engines was launched into deep space by M-V rocket on May 9, 2003. After vacuum exposure and several runs of baking for reduction of residual gas the ion engine system established the continuous acceleration of the spacecraft toward an asteroid. The Doppler shift measurement of the communication microwave revealed the performance of ion engines, which is 8mN thrust force for a single unit with 3,200sec specific impulse at 23mN/kW thrust power ratio. At the beginning of December 2003 the accumulated operational time exceeded 7,000 hours and units.

著者

葛山 浩 小紫 公也 荒川 義博

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.54, no.625, pp.63-70, 2006 (Released:2006-03-20)

参考文献数

29

被引用文献数

1 2

---

An air-breathing pulse laser powered launcher has been proposed as an alternative to conventional chemical launch systems. The trajectory from the ground to a geosynchronous transfer orbit by pulse laser propulsion is calculated by modeling the thrust during pulsejet, ramjet and rocket flight modes, and the launch cost is estimated. The results show that the pulse laser powered launcher can transfer 0.085kg payload per 1MW beam power to a geosynchronous orbit, and the cost becomes quarter of existing systems if one can divide a single launch into 22,500 multiple launches.

著者

安田 邦男

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.47, no.547, pp.314-320, 1999-08-05 (Released:2009-07-09)

参考文献数

7

被引用文献数

1 2

---

A wind tunnel test was conducted to study the mechanism of a flight of a flying disc which flies while rotating. A Flying disc is a rotating disc without blades, being different from the rotor of a helicopter and the like and its cross sectional shape is a unique upward convex. Using a production flying disc used at an official game, wind tunnel tests were performed. Forces were measured to investigate aerodynamic characteristics of an object of such a shape. In addition, a flat disc was also experimented for a comparison. Free flight tests of the flying disc were carried out to obtain base line data to experiment in the wind tunnel test. Flight data of the flying disc in free air was reduced by analyzing the flight path from the video tapes which recorded the flights of the flying disc. Smoke visualization tests were also made to visualize the flow pattern around the flying disc.

著者

炭田 潤一郎 安井 久子 坂野 鈴夫 竹内 明雄

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.47, no.540, pp.24-32, 1999-01-05 (Released:2009-07-09)

参考文献数

3

---

The QF-104 is a remotely-piloted full-scale drone developed from F-104, which is excellent in the speed performance. Its development program began in 1992 with all the mission by JASDF being completed in March 1997. The drone is operated from the fixed-type ground cockpit using a front view by TV. It has 150msec lag in control. TV camera has limited view angle of 46° in azimuth, 35° in elevation. Those generated difficulties in controlling the aircraft, especially in landing. Several devices were created to cope with the problems, as follows, Landing guidance symbols by vectoring capabilities of the tracking antennas show the deviation from the proper approach-path on the TV screen. Deflection command control laws with heading/wings-level hold mode are proved effective in smooth landing. Yaw string in the nose radome, AOA tone indication, touch down information, and 35 feet over-runway signal are also proved effective.

著者

永井 俊一 大竹 智久 本橋 龍郎

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.56, no.656, pp.442-448, 2008 (Released:2008-09-25)

参考文献数

8

---

We studied effect of ventilation ports on aerodynamics of the fuselage of a human-powered airplane and cooling performance of the pilot. An opening made in the fuselage is one of remedies for enhancing the performance of the pilot. On the other hand, the opening influences aerodynamic characteristics of the airplane, in particular the drag of the fuselage. When the ratio of inlet and outlet areas is larger than 3.0, the flux of air taken at the inlet is almost proportional to the area of inlet and depends weakly on the position and area of the outlet. Cooling of the pilot is estimated from the data of Nusselt number around the cylinder in the uniform flow at the Reynolds number defined by a velocity averaged over a cross section. An additive drag due to interaction between the injected flow from the outlets and the ambient flow around the fuselage depends strongly on the location of the outlet; the nearer to the trailing edge the outlet position moves, the less the drag increases.

著者

榊 和樹 角銅 洋実 中谷 辰爾 津江 光洋 五十地 輝 鈴木 恭兵 牧野 一憲 平岩 徹夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.63, no.6, pp.271-278, 2015 (Released:2015-12-05)

参考文献数

20

被引用文献数

1

---

The pintle injector is one of the most promising candidate for propellant injection systems of liquid rocket engine combustors due to the throttling capability and simple structure. However, combustion characteristics of pintle injectors are still unclear. Therefore, combustion experiments are conducted for an ethanol/liquid oxygen rocket engine combustor with a planar pintle injector which simulates the injection configuration of a pintle injector and enables optical measurements at Pc=0.40MPa and O/F=1.08-1.56. Direct images of the flame structure and CH chemiluminesence are observed through an optical window using high speed imaging techniques. Backlit images of the spray structure are observed. Strong CH chemiluminescence is observed in the vicinity of the impinging point of the two propellants. Luminous flames are observed in the vicinity of the faceplate and the upper wall of the combustor. It is observed that atomization process of the planar pintle injector proceeds two-dimensionally unlike conventional impinging injectors. A periodic atomization behavior is observed with the frequency of approximately 700Hz, being equal to the frequency of the Kelvin-Helmholtz instability.

著者

長谷川 裕晃 北原 一起 犬飼 保夫

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.50, no.582, pp.272-272, 2002 (Released:2003-09-02)

参考文献数

5

被引用文献数

2 1

---

The Air Turbo Ramjet (ATR) is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds and therefore the ATR is an attractive propulsion system for the wide operation range (e.g. Mach 0 to Mach 4). The ATR can provide a higher specific impulse than a solid fuel rocket engine and a higher thrust per frontal area than a turbojet engine. The major ATR components are the inlet, fan (compressor), turbine, gas generator, combustor and exhaust nozzle. In the ATR, the turbine drive gas is generated by a decomposed liquid or solid fuel gas generator. In order to carry heavier payloads and to attain shorter flight time, the compact and high thrust engine is required. In this study, the ram combustor with the double-staged flameholders and the fan with tandem blade were introduced to shorten the engine length and to increase the fan pressure ratio, respectively. Furthermore, the engine testing was carried out on sea level static condition to confirm the engine component integration technologies for the ATR propulsion system.

著者

糸賀 紀晶 井星 正氣 沖田 理香 佐藤 旭

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.61, no.6, pp.174-180, 2013 (Released:2014-06-27)

参考文献数

7

---

To land a helicopter on a flight deck of a ship is said to be one of difficult operations even for experienced pilots because the helicopter rotor is affected by complex flows, e.g. ship airwakes and interference flows formed between the rotor and superstructures, in addition to ship motions. Therefore, it is important to grasp quantitatively influence of these complex flows on the helicopter rotor for securing the safe deck-landing. In this paper, CFD analysis of helicopter rotor operating over a flight deck is done by solving unsteady 3D compressible Euler equations with an overlapped grid system. The superstructure on a flight deck is modeled by a simple sharp edged bluff body. Parameters for numerical analysis are landing spot and relative wind speed to the rotor and ship. Effects of these parameters on the rotor torque, flowfields around the rotor and inflow distributions on the rotor disc are clarified.

著者

山根 秀公 松永 易 草川 剛

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.56, no.649, pp.80-87, 2008 (Released:2008-03-11)

参考文献数

15

被引用文献数

1 1

---

A flyable FADEC system engineering model incorporating Integrated Flight and Propulsion Control (IFPC) concept is developed for a highly maneuverable aircraft and a fighter-class engine. An overview of the FADEC system and functional assignments for its components such as the Engine Control Unit (ECU) and the Integrated Control Unit (ICU) are described. Overall system reliability analysis, convex analysis and multivariable controller design for the engine, fault detection/redundancy management, and response characteristics of a fuel system are addressed. The engine control performance of the FADEC is demonstrated by hardware-in-the-loop simulation for fast acceleration and thrust transient characteristics.

著者

林 健太郎 麻生 茂

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.52, no.600, pp.38-44, 2004 (Released:2004-02-19)

参考文献数

18

被引用文献数

2 3

---

An experimental study on reduction of aerodynamic heating due to opposing jet in supersonic flow has been conducted. Experiments are conducted by using a conventional blowdown type wind tunnel. A hemisphere model is installed into supersonic free stream of Mach number of 4 and coolant gas is injected through a sonic nozzle at the top of the model. Significant decrease of surface heat flux distribution is observed and opposing jet is proved to be quite effective on the reduction of aerodynamic heating at the nose region of the blunt body. The effect of total pressure ratio of opposing jet to the free stream on the reduction of aerodynamic heating is also investigated.

著者

太田 貴之 梅村 章

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.49, no.574, pp.382-387, 2001 (Released:2002-04-26)

参考文献数

8

被引用文献数

3 2

---

Parametric study is conducted to find the optimum condition of water rocket for long flight, provided that the tank volume is prescribed. The parameters considered in the present study are the initial air pressure, water volume fraction, empty rocket mass, launching angle and bottle diameter which significantly affect the flight performance of water rocket. First, we calculate the temporal changes in tank pressure, water and air issue speeds and thrust, on the basis of a simple physical model which has been experimentally validated. Then, this model is incorporated into the equation of motion to calculate the ballistic flight of water rocket with various parameter values. As a result, it is found that PET bottles in the market are one of the most suitable for use as the pressure tank of water rocket.

著者

中谷 辰爾 野村 俊貴 引地 悠太 田中 信太郎 崔 敏鎬 今村 宰 津江 光洋 富岡 定毅

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.61, no.6, pp.151-158, 2013 (Released:2014-06-27)

参考文献数

38

---

Experiments on the effects of thermally cracked components of n-dodecane on the ignition and the combustion performance of a scram jet model combustor at Mach 2 were performed. Gaseous components of the thermally cracked n-dodecane at various temperature and 1MPa were measured by a gas chromatograph. Surrogate mixtures including hydrogen, methane, ethane and ethylene were injected into the supersonic air stream in the model combustor, and ignition and combustion behaviors were investigated at total temperatures of 1800 to 2400K. Pressure measurements on the combustor wall and optical observations of combustion using a high speed video camera were conducted. Results indicated that three combustion modes of intensive, transient and weak combustions were observed. Ignition was observed in the boundary layer positioned at the downstream of the cavity, and the flame propagated upward to the cavity. The ignition performance of ethylene was superior to methane and ethane, and their performances were elucidated from the reactivities predicted by a 0-dimensional calculation of chemical reactions for stoichiometric mixtures. An increase in the methane concentration reduced the ignition performance, and an increase in ethylene enhanced the ignition and combustion.

著者

沢田 雅洋 山下 博 岩崎 俊樹 大林 茂

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.58, no.681, pp.295-301, 2010 (Released:2010-10-27)

参考文献数

14

---

Research of Long-Distance Human-Powered Flight has been performed through the following four items: Aircraft design, Risk management, Pilot performance, Weather prediction. Actual flight took place on August 12, 2009. The flight distance was 20.72km. In this study, results of weather prediction using 1-way downscaling technique are validated by surface observation data and feasibility of weather prediction for Long-Distance Human-Powered Flight is discussed. The weather prediction with 1-km mesh decreases RMSE of wind speed by 0.1--0.2m/s compared with that with 5-km mesh. The weather prediction with 1-km mesh also has a potential to reproduce nonstationary wind. The RMSE gradually increase with time, which is mainly caused by initial and boundary data given from coarse mesh model. To reduce the RMSE, it is desirable to use newest analysis data as possible for initial and boundary data.

著者

吉川 俊明 坂本 慎介 堀 琴乃 楠本 寛 山本 康 服部 高資 佐多 宏太

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences (ISSN:13446460)

巻号頁・発行日

vol.56, no.655, pp.391-395, 2008-08-05

参考文献数

7

被引用文献数

1 1

---

In this paper, we propose the method for the measurement of required power and the adjustment of optimum gear ratio in take-off ground running. To get the values of required power and speed, we measured torque of the left side and the right side of pedals, RPM of pedals, and speed of the cockpit frame. In order to improve the take-off speed, some drums were applied, and the optimum gear ratio of the front drum to the rear drum was determined.

著者

佐原 宏典 小林 悠也 中村 健二郎 尾又 由佳乃 阿部 圭典 染谷 昴 西尾 勘汰 飯塚 俊明

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.67, no.6, pp.205-210, 2019 (Released:2019-12-05)

参考文献数

20

被引用文献数

2

---

Microsatellites are now in vogue and a lot of and a variety of missions using them are progressed in the world, some of them require propulsion system to realize a highly precise attitude control or orbit transfer. In order to satisfy the requirements, we are developing Microsatellite-Friendly Multi-Purpose Propulsion System, MFMP-PROP, with capabilities of both mono-propellant and bi-propellant modes to provide both of small impulse bit and large delta-V, under the policies of Safety First, Border Free, Effective COTS, and Easy Scalability, based on the techniques of 60wt% Hydrogen Peroxide. We conducted captive tests of a thruster for mono-propellant mode under bi-propellant mode to confirm its stable ignition and continuous operation, and obtained performances under its pre-heating temperature and mixing ratio of hydrogen peroxide and ethanol, of 160 seconds of specific impulse at the highest.

著者

大竹 智久 中江 雄亮 本橋 龍郎

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.55, no.644, pp.439-445, 2007 (Released:2007-10-10)

参考文献数

17

被引用文献数

29 64

---

Aerodynamic characteristics of NACA0012 airfoil at low Reynolds numbers (Re=1.0×104∼1.0×105) are measured systematically to clarify nonlinearity of the aerofoil characteristics. The variation of the lift curve with the angle of attack is divided into 5 sub-regions; the gradient of the lift curve much depends on the incident angle. Negative values of the gradient of lift coefficient are observed at lower angles of attack in a Reynolds numbers range. The sub-regions are summarized in a diagram of angle of attack and Reynolds numbers. The coefficients of drag and moment around 0.25 chord length have also unique characteristics.

著者

渡辺 力夫 冨田 信之 竹前 俊昭

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.51, no.593, pp.314-320, 2003 (Released:2003-09-26)

参考文献数

17

被引用文献数

2 2

---

The propulsive characteristics of water rockets are analyzed theoretically and experimentally. The unsteady thrust force acting on a PET bottle and the air pressure inside the bottle are measured simultaneously by the thrust test stand we have developed. The semi-empirical thrust history is obtained utilizing the air pressure history and it is compared with the measured thrust history. The results show qualitative agreement. The observation of the flow inside bottle by a high-speed video camera shows that the air precedes water when it is about to be discharged entirely. We have developed a flow regulator attached to the nozzle cap to reduce the precursor air discharge that is considered as a result of the swirling flow inside the bottle. The experimental results show that the air discharge and the body vibration are suppressed effectively.

著者

大津 広敬 安部 隆士 船木 一幸

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.54, no.628, pp.181-188, 2006 (Released:2006-06-30)

参考文献数

17

被引用文献数

3 2

---

An applicability of the electrodynamic heat shield system to super-orbital reentry vehicles was investigated. In the case of the super-orbital reentry flight, due to the strong ionization reactions inside the shock layer, the heat shield system which utilizes the electromagnetic force is expected to work well. In the present study, in order to evaluate the reentry heating reduction by this heat shield system, we performed a CFD analysis including thermochemical non-equilibrium effects and an electromagnetic force. The flight condition used for the present study is that the velocity is 11.6km/s at the altitude of 64km at which the stagnation point heat flux of the MUSES-C reentry capsule is considered to be the maximum value. From our CFD results, we found that the heat flux to the vehicle could be reduced by up to 50%. Additionally, it was also found that the drag coefficient increased with the magnetic field strength, and the maximum value of the drag coefficient was 2.0 with the magnetic field strength of 0.6[T].

著者

井星 正氣 糸賀 紀晶 前田 孝一 J. V. R. Prasad

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.52, no.606, pp.302-308, 2004 (Released:2004-08-05)

参考文献数

15

被引用文献数

1 3

---

Modern day helicopters are frequently required to operate close to non-uniform ground surfaces. During operations above a moving ship deck, it can be foreseen that the hovering performance of the rotor has very different behavior compared with the cases of hovering above stationary flat ground plane. In this report, the hovering performance of the rotor above the moving ground in full ground effect is experimentally studied in order to provide qualified database for the validation of analytical study on dynamic ground effect. The moving ground is simulated by means of harmonic rolling and heaving motions of ground effect plate with variable amplitude and frequency. The thrust, torque and blade flap angle of the rotor were measured at rotor height from 0.4 to 1.5. It is shown that motion types of the ground and the amplitude and frequency of the moving ground have important effects on the variable loads in and out of the rotor disk in dynamic ground effect.

著者

渡辺 力夫 冨田 信之 竹前 俊昭

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.52, no.609, pp.449-455, 2004 (Released:2004-11-30)

参考文献数

12

被引用文献数

1

---

The aerodynamic characteristics of water rockets are analyzed experimentally by wind tunnel testing. Aerodynamic devices such as vortex generators and dimples are tested and their effectiveness to the flight performance of water rocket is discussed. Attaching vortex generators suppresses the unsteady body fluttering. Dimpling the nose reduces the drag coefficient in high angles of attack. Robust design approach is applied to water rocket design for flight stability and optimum water rocket configuration is determined. Semi-sphere nose is found to be effective for flight stability and it is desirable for the safety of landing point. Stiffed fin attachment is required for fins to work properly as aerodynamic device and it enhances the flight stability of water rockets.