著者

丸山 祐一

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.57, no.667, pp.309-316, 2009 (Released:2009-08-17)

参考文献数

18

被引用文献数

2 1

---

Two kinds of methods of explaining the physical mechanism of the Magnus effect are compared with each other and fully discussed. The first method uses Bernoulli's theorem and the fluid velocity difference between both sides of the body. The second one is based on the momentum theorem which relates the lift force with the fluid acceleration perpendicular to the uniform flow direction, which is caused by the asymmetry of separation points. It is shown that the latter method is preferable because it can be strictly applied to the real flow field containing both the rotational and the irrotational flow regions.

著者

勝部 駿 佐原 宏典

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.70, no.1, pp.1-6, 2022 (Released:2022-02-05)

参考文献数

5

---

In spacecraft systems, it is important to quickly detect and deal with anomalies. However, the increasing complexity of spacecraft systems makes it difficult to avoid failures using previous anomaly detection methods. In recent years, anomaly detection methods based on machine learning have been studied. But it is difficult for a spacecraft to detect anomalies autonomously in orbit. In this study, we propose an anomaly detection method that defines and monitors a single variable representing the health status of a spacecraft system, instead of monitoring a huge amount of telemetry data. We have confirmed that the single variable can represent the health status of a spacecraft system and can be applied to the anomaly detection method.

著者

東野 和幸 杉岡 正敏 棚次 亘弘 湊亮 二郎 笹山 容資 磯田 浩志

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.60, no.3, pp.115-120, 2012 (Released:2012-10-23)

参考文献数

8

被引用文献数

1 1

---

The pyrolysis of Methylcyclohexane (MCH) is investigated for the purpose of a regenerative cooling system of hypersonic propulsion by using Endothermic Fuel (EF). The experimental apparatus has heating tube made from INCONEL alloy where MCH would pass through and be decomposed. To confirm the effects of endothermic reaction on the heat absorption, heat fluxes are measured at 9 cross sections in this heating tube. For each section, temperatures are measured at the inner and the outer radii of heating tube and heat flux can be evaluated by these temperature differences. The experimental results show that the endothermic reaction of MCH can confine the temperature increment of MCH in the heating tube and increase the heat fluxes when its temperature was greater than 900K. The numerical simulation can also indicate that MCH pyrolysis have begun around the same temperature. The chemical heat capacity by MCH pyrolysis can increase its total heat capacity to 1.4 times. These facts indicate the usefulness of the endothermic fuels and the possibilities of the regenerative cooling by them.

著者

越智 徳昌

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.598, pp.621-627, 2003 (Released:2003-11-28)

参考文献数

8

被引用文献数

1 2

---

Precise normal acceleration control is essential for missile guidance. Missiles with both front and rear control surfaces have a higher ability to control normal acceleration than missiles with front or rear control surfaces only. From the viewpoint of control, however, the control problem becomes a two-input-one-output problem, where generally control input cannot be determined uniquely. This paper proposes controlling angle of attack as well as normal acceleration, which makes the problem a two-input-two-output one and determines the controls uniquely. Normal acceleration command is given by a guidance system, but angle of attack command must be generated in accordance to the acceleration command without affecting the normal acceleration control. This paper also proposes such a command generator for angle of attack. Computer simulation is conducted using a nonlinear missile model to investigate the effectiveness of the control system along with control systems designed using three other methods.

著者

松永 三郎 神澤 拓也 狼 嘉彰

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.550, pp.433-441, 1999-11-05 (Released:2009-07-09)

参考文献数

7

被引用文献数

2 1

---

This paper discusses a method for damping the angular momentum of an uncontrolled target satellite in order to make it easy to capture using a chaser-satellite-mounted manipulator. During the capture operation of an uncontrolled floating target, it may be difficult for a manipulator to grapple it directly because of target nutation or tumbling. In this paper, we propose using a cushion type damper in order to absorb the rotational motion. The scenario is as follows: 1) a cushion type damper is attached to the end-effector of the manipulator, 2) the manipulator softly pushes the damper on carefully selected points on the target, and 3) the contact force between the damper and the target causes the angular momentum of the target to decrease. The validity and feasibility of the proposed method are verified through numerical simulations.

著者

小林 弘明 吹場 活佳 本郷 素行 佐藤 哲也 溝端 一秀

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.418-425, 2007 (Released:2007-10-10)

参考文献数

8

---

Experimental studies on telescopic aerospikes for aerodynamic control are reported in this paper. Parametric study on the aerodynamic characteristics of the aerospike has performed including the effect of spike length L, base diameter of tip cone D, spike translating speed and direction. The Axial force coefficient Ca of the aerospike suddenly increases at L/D=3.0 due to flow mode transition from the separation to the reattachment. Reattachment/separation flow mode transition phenomenon can be applicable to a newly invented aerodynamic control device, which is called air-breathing aerospike. In this paper, verification test results of this air-breathing aerospike are also reported. A small solenoid valve in the body cylinder successfully controls reattachment/separation flow mode transition at the angle of attacks from 0 to 12 degree. The spiked bodies’ Ca varies according to the mode transition. As a result, we can control the aerodynamic property of the spiked body by opening/closing the valves periodically.

著者

小松 敬治 佐野 政明 角田 義秋

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.591, pp.158-163, 2003 (Released:2003-09-16)

参考文献数

10

被引用文献数

3 2

---

Progress in materials technology has produced a much more durable synthetic fabric envelope for the non-rigid airship. Flexible materials are required to form airship envelopes, ballonets, load curtains, gas bags and covering rigid structures. Polybenzoxazole fiber (Zylon) and polyalirate fiber (Vectran) show high specific tensile strength, so that we developed membrane using these high specific tensile strength fibers as a load carrier. The main material developed is a Zylon or Vectran load carrier sealed internally with a polyurethane bonded inner gas retention film (EVOH). The external surface provides weather protecting with, for instance, a titanium oxide integrated polyurethane or Tedlar film. The mechanical test results show that tensile strength 1,000 N/cm is attained with weight less than 230g/m2. In addition to the mechanical properties, temperature dependence of the joint strength and solar absorptivity and emissivity of the surface are measured.

著者

河原 淳人 岩堀 太紀 山川 宏 佐藤 亨 山本 衛 橋口 浩之

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.64, no.3, pp.189-199, 2016 (Released:2016-06-05)

参考文献数

18

---

Shape estimation of space debris is an important task in evaluating its trajectory evolution and collision probability with resident objects in space. This paper shows the magnitude and rotation of space debris can be estimated by investigating the Doppler shift with a Single Range Doppler Interferometry (SRDI) method. The theory of SRDI method is discussed and its usefulness is confirmed by numerical simulations. Furthermore, fluctuation of Doppler shift of known space debris were successfully observed by the MU radar of Kyoto University and the size and spin rate of some space debris were successfully estimated.

著者

杉浦 綾 横関 智弘 平野 義鎭

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.5, pp.133-140, 2013 (Released:2013-10-25)

参考文献数

24

---

This paper describes the development and the wind tunnel test of a variable geometry morphing airfoil using corrugated structures. Feasibility of a morphing wing with corrugated flexible seamless flap-like structure is verified by the finite element analysis, and a prototype is manufactured using carbon fiber reinforced plastics. For the actuation system, two servomotors are installed inside the prototype wing to control the airfoil shape by the chord-wise tension of the connected wires. Successful actuation of the prototype wing is demonstrated under the air speed up to 30m/s in the wind tunnel test. Basic aerodynamic properties are also evaluated in comparison to traditional airfoil with a hinged control surface. Lift increase of variable corrugated wing is recognized when the flap angle increases.

著者

元田 敏和

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.638, pp.117-124, 2007 (Released:2007-04-20)

参考文献数

15

---

In aerospace projects preflight evaluation is crucial for mission success, because flight testing in a real environment is often difficult or impossible. Monte Carlo simulation is a powerful tool for the preflight evaluation because a nonlinear system incorporating various uncertain parameters can be evaluated directly. Monte Carlo simulation has been used in various aerospace projects throughout the world as the computer power increases. After the system evaluation, it is important to detect influential uncertain parameters which cause significant performance degradation so that measures for the system improvement can be studied. However, detecting those parameters is often uneasy because various uncertain parameters are incorporated simultaneously and their magnitudes are randomly generated in Monte Carlo simulation. An interaction of more than two uncertain parameters might be affected. This paper presents a simple approach to detect influential uncertain parameters applying a statistical test to the Monte Carlo results.

著者

中谷 辰爾 笠原 希仁 芝 世弐 大坂 淳 津江 光洋 河野 通方

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.610, pp.487-493, 2004 (Released:2005-01-05)

参考文献数

46

---

Numerical analysis of O3 depletions by exhaust plume from stratospheric flight at the altitude of 25km was conducted. Expanding box method was employed to simulate a diffusion of exhaust plume in the stratosphere. Concentrations of chemical species and normarized sensitivities of O3 concentration for reactions were estimated by fifth-order BDF method. Chemical kinetics include NOx, HOx and Ox chemistry. As results, it takes over two days that O3 concentration within a plume becomes ambient lebel within 1ppb. O3 perturbations were changed by an effect of plume-emission time, and they are bigger in daytime than in nighttime. Distributions of sensitivities of O3 concentrations for reactions are also changed for the plume-emission time. O3 depletion is greater by NOx than by HOx in exhaust plume.

著者

平田 邦夫 上條 謙二郎 升谷 五郎

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.53, no.614, pp.123-129, 2005 (Released:2005-05-20)

参考文献数

3

---

Idle spin phenomena were observed at rapid transient phase in liquid hydrogen pumps for rocket engines. Failure analyses were conducted and evaluation equations to estimate the shift of the operation point of the pump were derived in this paper. It was revealed that rapid fall of hydrogen flow rate resulted in decrease of pump efficiency which caused excessive temperature rise up to the saturation of the pump fluid.

著者

石本 淳 上條 謙二郎

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.51, no.592, pp.228-235, 2003 (Released:2003-09-26)

参考文献数

20

---

The basic characteristics of the two-dimensional cavitating flow of liquid helium through a horizontal converging-diverging channel near the lambda point are numerically investigated to realize the further development and high performance of new multiphase superfluid cooling systems. First, the governing equations of the cavitating flow of liquid helium based on the unsteady thermal nonequilibrium multifluid model with generalized curvilinear coordinates system are presented, and several flow characteristics are numerically calculated, taking into account the effect of superfluidity. Based on the numerical results, the two-dimensional structure of the cavitating flow of liquid helium though horizontal converging-diverging channel is shown in detail, and it is also found that the generation of superfluid counterflow against normal fluid flow based on the thermo mechanical effect is conspicuous in the large gas phase volume fraction region where the liquid- to gas-phase change actively occurs. Furthermore, it is clarified that the mechanism of the He I to He II phase transition caused by the temperature decrease is due to the deprivation of latent heat for vaporization from the liquid phase.

著者

川瀬 成一郎

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.58, no.673, pp.31-37, 2010 (Released:2010-02-19)

参考文献数

10

被引用文献数

2 2

---

In order to mitigate the overcrowding problem of geosynchronous orbits, we propose a monitoring satellite placed in a sub-synchronous, retrograde circular orbit. The monitoring satellite has an on-board optical sensor, and observes look-angles of the target geosynchronous satellites that come into the field of view one after another. This kind of monitoring makes it possible to determine the orbit of every target satellite in a short term. Covariance analyses show that the target position determination can be accurate to 350m. The monitoring satellite's orbit determination will be obtained from ranging at two ground stations, with a sufficient accuracy because range biases can be estimated.

著者

山井 洋一 本田 健一郎

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.71, no.4, pp.192-202, 2023 (Released:2023-08-05)

参考文献数

30

---

This paper proposes the evaluation methodology in early design phase for the feasibility of novel instrument layout to be applied for the next generation civil aircraft, based on the MIL-HDBK-46855A human engineering guideline that shows pilot evaluation and analysis method for military system. Airline pilots evaluation on mockup with this method facilitates to identify the critical design issue and its potential resolutions from visibility, its trajectory and crew coordination point of view and mitigate the risk for late finding of issue to avoid redesign in later design phase. The effectiveness of the evaluation method is potentially shown by the trial usage on the conventional instrument layout, and the achieved data can be used for a reference to compare it with the novel instrument layout design.

著者

本田 俊樹 山極 芳樹

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.579, pp.150, 2002 (Released:2003-08-19)

参考文献数

9

被引用文献数

1 1

---

This paper reports results of an improved model of “ionospheric hole” caused by rocket exhaust injected into the F-region. We have investigated a practical “ionospheric hole” model by which a proper strategy of rocket launch can be examined from a view point of protection of the Earth’s environment. The analytical results of preceding models were published about 8 years ago. The model well included the trajectory of launch rocket and could evaluate the effect of rocket exhaust on the Earth’s environment for various trajectories. The analytical results, however, didn’t quantitatively agree with the observation data very well. The new model includes the effects of the exhaust velocity of effluents and the neutral wind that preceding model didn’t take into account, and the boundary conditions and parameters are improved. The analytical results by this improved model well agree with the observation data for Skylab–I and HEAO–C launching experiments not only qualitatively but also quantitatively.

著者

伊勢 俊之 月崎 竜童 都甲 浩芳 小泉 宏之 國中 均

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.62, no.6, pp.212-218, 2014 (Released:2015-08-20)

参考文献数

12

---

The microwave ion thruster μ10's ion beam current saturated at a large mass flow rate when propellant gas was injected from a waveguide inlet and it was improved by additional propellant inlets to a discharge chamber. In order to understand the mechanism of these phenomena, it is important to measure distributions of the microwave electric field inside the discharge chamber, which is directly related to plasma production. In this study, we applied an electro-optic (EO) probe to measuring the microwave electric field. The probe contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. We measured electric-field profiles along the centerline and in the ECR area of μ10 with the EO probe. Consequently, this paper revealed that when the propellant was injected from the waveguide inlet, microwave was reflected in the waveguide at large mass flow rate, which disturbed a propagation of microwave to the ECR area. It also revealed that when the propellant was injected from the discharge chamber inlet, the mass flow rate where the microwave reflection occurred shifted to larger rate, which resulted in the increase of the beam current.

著者

東野 和幸 杉岡 正敏 小林 隆夫 湊 亮二郎 丸 祐介 笹山 容資 大塚 雅也 牧野 隆 坂口 裕之

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.57, no.664, pp.210-216, 2009 (Released:2009-06-01)

参考文献数

10

被引用文献数

3 2

---

Liquid Natural Gas (LNG) will be used as propellant of near future space vehicles and rocket engines. Cooling characteristics of engines, especially methane thermal cracking characteristics depend on material candidate for nozzle and chamber cooling passage material temperature. This paper describes these effects on coking and sample analysis method is suggested.

著者

奥村 哲平 増井 博一 豊田 和弘 趙孟 佑 今泉 充

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.647, pp.590-596, 2007 (Released:2007-12-27)

参考文献数

14

被引用文献数

6 7

---

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.

著者

藤田 和央

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.610, pp.514-521, 2004 (Released:2005-01-05)

参考文献数

11

被引用文献数

9 13

---

The air breathing ion engine (ABIE) is a new type of electric propulsion system which can be used to compensate the aerodynamic drag of the satellite orbiting at extremely low altitudes. In this propulsion system, the low-density atmosphere surrounding the satellite is taken in and used as the propellant of ion engines to reduce the propellant mass for a long operation lifetime. Since feasibility and performance of the ABIE are subject to the compression ratio and the air intake efficiency, a numerical analysis has been conducted by means of the direct-simulation Monte-Carlo method to clarify the characteristics of the air-intake performance in highly rarefied flows. Influences of the flight altitude, the aspect-ratio of the air intake duct, the angle of attack, and the wall conditions are investigated.