著者

庄山 直芳 藤本 浩司

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.19, pp.39-45, 2020 (Released:2020-01-31)

参考文献数

19

被引用文献数

1

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A concept study was performed on the spin-launch of a small orbital launch vehicle from a balloon. The small rocket is based on an existing sounding rocket SS-520, the smallest orbital rocket in the world. The increase in launch capacity was calculated by considering the velocity increment required to reach a low earth orbit. Three-dimensional trajectory analysis was performed to obtain the allowable elevation angle error to achieve an orbit insertion accuracy of 1 km in apogee altitude. A new attitude control system of the launcher hanging on a balloon, which uses a double gimbal control moment gyroscope (DCMG), was proposed to satisfy the launch safety requirement. The other issues to be addressed, including the combustion and dynamic behaviors of propellant at high altitude, the reusability of the launcher system, were also discussed.

著者

武田 真司 小出 紗英 大本 圭祐 坂本 啓 田中 宏明 石村 康生 大熊 政明

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.19, pp.151-158, 2020 (Released:2020-10-29)

参考文献数

10

---

For the observation of microwave in space over 100 GHz by radio astronomical satellites, this study develops shape-deformable antenna reflectors. When a certain portion of the antenna reflector prototype is deformed, the entire reflector is affected by the partial deformation. The purpose of this study is firstly clarifying the effect of coupling in reflector displacement. Secondly, this study tries the performance evaluation of hysteresis elimination by a piezoelectric strain feedback system under the effect of the displacement coupling. To achieve these objectives, this study quantifies the displacement coupling, the relations between piezoelectric strain and reflector displacement, and the residual reflector displacement error under the feedback control when multiple actuators are driven simultaneously. As a result, this study clarifies that there is a non-negligible coupling effect and the stress history dependence in the reflector surface deformation, causing the limit in the accuracy of the feedback system. Based on these experimental observations, this paper presents three design improvement plans that will possibly solve these problems.

著者

小幡 茂男

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.19, pp.71-80, 2020 (Released:2020-03-14)

参考文献数

57

---

SHSI, Supersonic Hot Streak Ignition, as a new concept of ignition system for supersonic combustion of hydrocarbon fuel in SCRAM jet engine installed on the small size hypersonic vehicle has been proposed. SHSI fuel of slight amount of hydrogen supplied into compressible turbulent boundary layer at forebody of the vehicle fuselage starts exothermic chemical reaction induced by high temperature at viscous sublayer, then during passing through intake and isolator the cold streak of pilot fuel is transformed to the hot streak as heat source for ignition and flame-holding at main combustor. Analytical research have been conducted to examine the potential for practical operation of SHSI. Damkohler number defined by the ratio between characteristic times of chemical reaction and flow is used to assess the possibility of forming of the hot streak, and it is found that the flight condition of Mach number around 5 at the relatively low altitude in the stratosphere is the limit to achieve auto-ignition of the anterior fuel. Also, compound compressible flow analysis based on one-dimensional stream-tube theory is applied to the validation of capability to avoid the fatal risk of engine unstart at the convergent part of intake, and it is confirmed that the biased distribution towards the downstream of heat release by the hot streak is effective to successfully suppress occurrence of the danger compound choking.

著者

栗原 真之 望月 俊希 得竹 浩

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術

巻号頁・発行日

vol.14, pp.7-15, 2015

被引用文献数

1

---

An attitude sensing system using thermopile sensors and inertial sensors was proposed. The output model of the thermopile sensor was constructed from the calibration experiment and the theoretical calculations. The estimation algorithm of the attitude angles was developed from the sensor output models using extended Kalman filter. Because thermopile sensor output correlates with attitude to the ground directly, the error of inertial sensors can be compensated. Additionally, the proposed system consists of commercial low-cost product. Numerical simulations and experiment were carried out and the performance was validated. Experimental result shows that the proposed system has precision of approximately 1.2°.

著者

上野 和之 鷲見 裕太 田坂 昂大 内山 順史

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.12, pp.25-30, 2013 (Released:2013-02-20)

参考文献数

15

---

Airships with small horizontal cross-section and tall height are proposed. Such vertical airships have a remarkable advantage with respect to available locations for landing and mooring. Flight tests and wind tunnel tests of vertical airships were carried out using scale models. Drag coefficient of vertical airships is discussed.

著者

上村 常治 鈴木 真二 柄沢 研治

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術

巻号頁・発行日

vol.12, pp.107-109, 2013

---

The aircraft descent profile has many factors, such as selected airspeed, flight weight, wind, initial altitude, and outside temperature even if fixed idle thrust was assumed. This article tries to prove a rule of thumb that "Even if the wind changes at lower altitude during descent, the flight path will converge at a lower altitude". This may be useful information for flight operation, if it is correct. In addition idle thrust descents are a useful method for fuel economy operation. This paper tries to support this rule of thumb by numerical simulations of flight paths with different wind conditions.

著者

羽生 宏人 和田 英一 丹羽 崇博 近藤 靖雄 川村 尚史 丸山 信也 岡村 彩乃 山科 早英良 永井 康仁 中道 達也 上道 茜 田中 成明 小林 直樹 笠原 次郎 森田 泰弘

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.9, pp.15-21, 2010 (Released:2010-05-14)

参考文献数

6

被引用文献数

1

---

The educational hybrid-rocket was successfully launched and it also landed within the predicted area. Aerodynamic characteristics of the rocket designed by students of Tsukuba University were evaluated by the wind tunnel testing with the support of Tokai University. The flight path affected by the environmental condition, especially wind direction and velocity, was simulated with the original calculation program. The altitude of the rocket was measured with the optical equipment and the apex was 123 m although the calculation indicated 198 m. We expected that the insufficient filling or the volatilization of Nitrous oxide as an oxidizer led to this result. And then, the apex was verified with a function of the oxidizer filling ratio. The results showed that 81.2 % of the oxidizer volume in comparison with the firing test condition was accumulated in the tank at the launch.

著者

宮沢 与和 ビクラマシンハ ナビィンダ キトマル 原田 明徳 宮本 侑斗

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.12, pp.31-38, 2013 (Released:2013-03-06)

参考文献数

10

被引用文献数

3 6 2

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In the future air transportation system, airspace will be efficiently used and each aircraft can optimize its own performance. Due to limited capacity of the airspace like terminal area, however, some sort of adjustment for each aircraft is necessary to maintain separation among multiple aircraft. Fixed arrival time is a basic solution to the problem. This paper studies the effect of arrival time assignment on the performance by assuming that each aircraft generates its own flight plan by minimizing its fuel consumption. Dynamic programming trajectory optimization is used to calculate the optimal flight profile composed of altitude and velocity. The result shows that the arrival time adjustment is efficiently performed in the descent phase, if the required amount of time to be adjusted is not large.

著者

蒋 理 大森 太加 柴田 寿一 今村 太郎 李家 賢一

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.14, pp.17-21, 2015 (Released:2015-02-13)

参考文献数

7

被引用文献数

1

---

Modified PARSEC (PARametric SECtion Method) is used as a parameterization method to describe airfoil shapes by few number of parameters, which is suitable for airfoil design optimization. To calculate these parameters, GA (Genetic Algorithm) is usually used. However, it has been observed that for some airfoils, Modified PARSEC method generates irregular shapes when GA is used. To overcome this issue, a new method using Pseudo-Inverse Matrix is developed. The proposed method is applied to various airfoils including the airfoil sections of the CRM (Common Research Model) wing, and a two-dimensional CFD code is used to carry out the aerodynamic analysis. Subsequently, the three-dimensional CRM wing is reproduced using the proposed method and its aerodynamic characteristics are analyzed with Euler equations. The results show that reproduced geometry is almost identical to that of the original CAD data in terms of aerodynamic characteristics, which shows the applicability and usefulness of the method.

著者

羽生 宏人 和田 英一 丹羽 崇博 近藤 靖雄 川村 尚史 丸山 信也 岡村 彩乃 山科 早英良 永井 康仁 中道 達也 上道 茜 田中 成明 小林 直樹 笠原 次郎 森田 泰弘

出版者

THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.9, pp.15-21, 2010

被引用文献数

1

---

The educational hybrid-rocket was successfully launched and it also landed within the predicted area. Aerodynamic characteristics of the rocket designed by students of Tsukuba University were evaluated by the wind tunnel testing with the support of Tokai University. The flight path affected by the environmental condition, especially wind direction and velocity, was simulated with the original calculation program. The altitude of the rocket was measured with the optical equipment and the apex was 123 m although the calculation indicated 198 m. We expected that the insufficient filling or the volatilization of Nitrous oxide as an oxidizer led to this result. And then, the apex was verified with a function of the oxidizer filling ratio. The results showed that 81.2 % of the oxidizer volume in comparison with the firing test condition was accumulated in the tank at the launch.

著者

亀井 卓也 伊藤 那知 菅井 慎也 太田 諭志 佐鳥 新 千葉 一永

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.12, pp.111-117, 2013 (Released:2013-11-28)

参考文献数

16

被引用文献数

1 1

---

Precision agriculture has been being implemented in order environmentally friendly and efficiently to product and manage crops. The remote sensing by satellite and aircraft is employed in order to obtain the information regarding the growth of crops. Although the data from satellites can include wide-range image each time, it is insufficient due to the fixed orbital path of satellites. Therefore, fixed-point observations cannot be sufficiently performed. Moreover, the observations on fixed orbital path cannot be always carried out because of cloud. Although aircrafts are used for the interpolation of the insufficient data by satellites, manned aircrafts need high personnel expenses and maintenance costs. Therefore, unmanned aerial vehicle (UAV) is recently employed. The objective of the present study is the development of the system to generate the interpolated image data by normalized difference vegetation index (NDVI) map taken by small-type UAV (sUAV), which is low-priced and simple system to implement precision agriculture. The following three assignments have been concretely performed in the present study; 1) light-weight four-band multispectral camera carried in sUAV will be developed, 2) sUAV is managed and the image data will be taken, and 3) NDVI map will be generated from the image data by sUAV and interpolated image data will also be developed to contribute precision agriculture. Consequently, the lightest four-band multispectral camera in the world has been developed, and also sUAV has been able to be successfully managed and acquired image data could also generates NDVI maps.