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佐藤 泰貴, 古谷 寛
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セッションID: S1903-1-5
発行日: 2010/09/04
公開日: 2017/08/01
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Preliminary experiments of a wrapping fold membrane are performed to determine the fold properties for the packaging density and the effects of the plastic deformation on the layer pitch. To determine the packaging density, relationships between the layer pitch of the folded membrane and the contact force applied to the membrane are examined experimentally. Fold FEM analyses using stress-strain relationships which are determined by a one-dimensional fold model are demonstrated to investigate the effects of the plastic deformation. As the results of these analyses, the critical layer pitch which doesn't have the plastic deformation is derived.
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青木 隆平, 古谷 寛, 樋口 健, 宮崎 康行, 石村 康生, 石澤 淳一郎, 泉田 啓, 岸本 直子, 角田 博明, 酒井 良次, 渡邊 ...
原稿種別: 本文
セッションID: S1903-1-6
発行日: 2010/09/04
公開日: 2017/08/01
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Space Inflatable Membrane structures Pioneering Long-term Experiments (SIMPLE) unit is one of ISS Japanese Experimental Module (JEM) Kibo's exposed facility payloads scheduled to be launched in 2012. Manufacturing and function testing phase of the engineering model (EM) has been completed and the proto-flight model (PFM) is now underway. The SIMPLE mission consists of three experimental verifications using Inflatable Extension Mast (IEM), Inflatable Space Terrarium (IST) and Inflatable Material Experimental Panel (IMP). The combination of the experiments is aimed to demonstrate the usefulness and viability of the inflatable structures and to acquire the basic operational data of the systems. The brief descriptions of each component of the SIMPLE experiments are presented and the idea of the verification project is summarized.
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田中 宏明, 齋藤 健太
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セッションID: S1903-2-1
発行日: 2010/09/04
公開日: 2017/08/01
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Shape repeatability of a cable-network structure with hysteresis is studied. An experimental model is built and some repetitious loads are applied on the model. Shapes of the experimental model are measured and changes in the shapes caused by the hysteresis and the material nonlinearities are quantified. Characteristics of cables are modeled and some numerical simulations are carried out. The experimental results are compared with the numerical simulations to investigate effects of hysteresis and material nonlinearities.
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觀音寺 貴之, 目黒 在
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セッションID: S1903-2-2
発行日: 2010/09/04
公開日: 2017/08/01
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The purpose of this study is to establish a new design methodology for lightweight cable-mesh antenna reflectors for the future communication satellites. In this study, we propose a new design methodology for a system of cables. We would design a system of cables stable against a deformation of the supporting structure. When a large deformation is allowed to the supporting structure, the structure can be designed simpler and lighter. Then the lighter and larger antenna reflector can be obtained. To demonstrate our design methodology, we've designed and manufactured "umbrella antenna", whose diameter is 1.4 m. 3D measurement of reflector surface and FEM analysis was performed to estimate surface accuracy and deformation modes. As a result, we found allowable deformation modes (homologous deformation modes) and the minimum requirement of bending stiffness of a supporting structure.
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上土井 大助, 古谷 寛
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セッションID: S1903-2-3
発行日: 2010/09/04
公開日: 2017/08/01
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In studies on construction methods for large structure of Space Solar Power Systems, Japan Aerospace Exploration Agency aims for demonstration of construction technology for 100m-class space structure between 2015 and 2020. When the H-2B rocket transports the materials of 100m-class space structure, they must be divided into some modules to store them in the rocket fairing. So, it's necessary to dock modules in orbit. In this study, we propose the effective methods to dock modules automatically in orbit. We try to the simplification of the docking function by distributing the function of the structure module and the docking equipment and aim to propose the high reliability and low-cost methods.
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矢口 依穂, 目黒 在
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セッションID: S1903-2-5
発行日: 2010/09/04
公開日: 2017/08/01
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The object of this study is to establish a new design methodology for ultra-light-weight solar array paddles, which is defined as "an integrated structure". Future solar array paddles applied for space explorations would require high power that greatly exceeds 100 W/kg. We would like to propose a hinge-less, ultra-light-weight deployable solar array paddle as a functional/structural integrated structure. By giving a curvature, the out-of-plane loading on a thin plate is transferred into the in-plane loading. The important issues to be considered are how to keep the given curvature during various kinds of loading. We have designed and analyzed a curved membrane structure implemented with tendon cables and/or thin strips. The tendon cables can improve eigen frequency of the curved membrane by transforming a lower deformation mode to a higher mode. The strips also improve eigen frequency of the curved membrane by increasing geometric moment of inertia. More mass is needed for the strips. By combining the tendon cables and the strips, much more improvement can be obtained as a synergic effect. In the most effective case, 75 times higher stiffness than flat membrane can be obtained.
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西田 信一郎, Cian Cran
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セッションID: G1900-1-1
発行日: 2010/09/04
公開日: 2017/08/01
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On the moon, the assembly of structures, such as observation equipment, an antenna and a resource utilization processing unit, and a hangar, is assumed. The mobile lunar robot which can move free in the surface is effective in the assembly of a structure. In this paper, supposing performing the structure assembly in such lunar environment with a mobile robot, since the assembly method of the reflector of a sunlight condensing furnace was considered as an example, the result is reported.
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Yoshitaka SAKAMURA, Shuichi UESUGI, Katsuyuki NAKAYAMA
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セッションID: G1900-1-2
発行日: 2010/09/04
公開日: 2017/08/01
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To assess the risk of flying fragments generated during accidental explosions in aerospace activities, we have been developing a class of numerical simulation codes for predicting their trajectories and impact conditions. In these codes, the equations of motion of solid bodies are solved with an inviscid flow solver, in which a high-resolution, finite-volume upwind scheme is used, and complex moving boundaries are treated by using a Cartesian cut cell method. In the present work, a two-dimensional version of our code has been validated against the result from a shock tube experiment, in which the two-dimensional shock-induced motion of a solid object was visualized using a high-speed video camera.
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岩城 裕樹, 戸谷 剛, 脇田 督司, 永田 晴紀
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セッションID: G1900-1-3
発行日: 2010/09/04
公開日: 2017/08/01
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The variation of the thrust and the specific impulse was revealed numerically with calculating the change of the exhaust velocity. Both cooling and heating the propellant flowing in the divergent section of Laval nozzle were treated. The expansion ratio were 30, 600, and 2000. The specific heat ratio was 1.3. Two types of heat profile were considered; pulsed heat transfer (PHT) and distributed heat transfer (DHT). The relations of Rayleigh flow and isentropic change were used for PHT. The exhaust velocity is higher than the isentropic value in the case that the heat is provided near the throat. In other cases, the exhaust veolocity is less than the isentropic case. The equivalent point of heat transfer is introduced for DHT. Results of DHT is coincident with PHT by using this equivalent point. This results indicates that the effect with DHT can be predicted from PHT.
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米元 聖貴, 榎 伯仁, 佐宗 章弘
原稿種別: 本文
セッションID: G1900-1-4
発行日: 2010/09/04
公開日: 2017/08/01
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This paper reports the thrust performance of a steady-state, applied-field MPD arcjet thruster. At low mass flow rates, electromagnetic acceleration characteristics were investigated with varying propellant species, discharge current and magnetic field. When mass flow rate is 4.2mg/s, voltage drop was measured by 0.2V in a single operation. Voltage drops were also measured through several operations. These are thought to be causally cathode changes. The ends of cathodes after operations expanded and became bumpy. In a single operation, both high voltage mode and low voltage mode were measured when mass flow rate, discharge current, magnetic field were constant. These modes relativity remain to be explained.
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波多 英寛, 藤原 和人, 廣江 哲幸
原稿種別: 本文
セッションID: G1900-1-5
発行日: 2010/09/04
公開日: 2017/08/01
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The purpose of this study is to discuss the electrical propulsion system using wire explosion phenomenon. The pulsed electrical propulsion system is using produced expansion gas as a result of exploding metallic wires using a high-voltage. This paper evaluated pulse electrical propulsion system by fundamental experiment using aluminum wire. The experiment was using power supply unit of 220 voltage and 680-6120μF. In this result, the max impulse bit was about 8400μN-sec, the specific impulse was about 8100 sec.
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荻田 直弥, 佐宗 章弘
原稿種別: 本文
セッションID: G1900-1-6
発行日: 2010/09/04
公開日: 2017/08/01
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The performance of laser ablation propulsion using fine particles made of polyacetal is investigated. We expected that the absorption efficiency of fine particles was better than one of bulk. 2 sizes of fine particles were used. The momentum coupling coefficient (C_m) and mass loss were measured. The C_m of small, fine particles is larger than one of bulk. Due to fine particles splashing, the mass loss of fine particles was more than 10^2 times larger than that of bulk. In order to decrease the splashed mass, the fine particles were bonded with hydraulic compression. The C_m of compacted fine particles was comparable to that of bulk target.
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金田 照彦, 奥山 圭一, 加藤 純郎, 大矢 洋明
原稿種別: 本文
セッションID: S1904-1-1
発行日: 2010/09/04
公開日: 2017/08/01
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A carbon fiber reinforced plastic (CFRP) has been widely used as a heat shield material in aerospace community. The CFRP is very trusted as the heat shield material for a re-entry vehicle but a fuselage becomes heavy because the CFRP is the high density material. Very recently, Okuyama developed a new ultra light-weight CFRP that is called LATS. In order to design the lightweight re-entry vehicle, this paper describes the thermal characteristics of the LATS in the high enthalpy flow. Furthermore, this paper described a comparison of the thermal characteristics of the LATS and the conventional high density CFRP. It found that the surface and in-depth temperatures of both resembled well as these experiment. The LATS can be applied to the heat shield material for the re-entry vehicle.
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栗林 充伸, 酒井 武治, 北川 一敬, 平井 研一
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セッションID: S1904-1-2
発行日: 2010/09/04
公開日: 2017/08/01
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Optical attenuation characteristics in the shock layer for carbonaceous material and Teflon heated in arc jet wind tunnel flows are examined. A He-Ne laser beam is passed ahead of a blunt body in a direction perpendicular to an arc jet flow and the temporal history of the intensity of the laser is measured. The results show that no optical attenuation is observed in arc jet freestream and in a shock layer for the case of Teflon. For the carbonaceous material, intermittent optical attenuation is observed when the laser beam is passed in and probably ahead of the shock layer. This behavior is believed to due to the particulate interference of the laser beam. The particles are likely ejected from the carbonaceous material due to spallation.
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小澤 正裕, 柴田 竜司, 舩津 賢人, 白井 紘行, 高草木 文雄
原稿種別: 本文
セッションID: S1904-1-3
発行日: 2010/09/04
公開日: 2017/08/01
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In order to investigate silicone carbide (SiC) ablation properties, ablation experiments were performed by inserting a SiC test-piece into a high-temperature air plasma freejets. Carbon (C) was also tested to compare with SiC. Radiations from the ablating materials were measured spectroscopically and some chemical species originated by ablation were identified preliminarily. The bands of OH and CN, and atomic lines of O and Si were observed for SiC ablation.
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伊藤 豊大, 高木 誠, 松室 照仁, 北川 一敬, 保原 充
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セッションID: S1904-1-4
発行日: 2010/09/04
公開日: 2017/08/01
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Arc heated ground testing facility produce high enthalpy and high temperature gas flow which are used to investigate for purposes as thermal protection testing of reentry flow into the other planet. The emission spectra profiles in shock layer of the ablation materials are spectroscopically measured for CO_2 arc plasma flow. Vibrational temperature obtained from Boltzmann plot method for C_2 SWAN at 20mm upstream of the sonic throat and shock layer in bow shock around the blunt body. The d^3Π_g-a^3Π_u transition of Δυ=0 of C_2 SWAN, is referred from 509 to 516 nm. Vibrational temperature is determined to be 3500 K of SiC from band head ratio of incline to (0,0)-(2,2) of the C_2 SWAN band system emission. Virgin structure can be seen in the crystallization and lapping defect on surface, while structure after arc heating is changed recrystallization due to high enthalpy CO_2 gas flow.
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木原 尚, 神坂 直志, 安倍 賢一
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セッションID: S1904-1-5
発行日: 2010/09/04
公開日: 2017/08/01
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Numerical simulation of thermal response of ablator was carried out. In addition to the temperature measurement inside of an ablator and surface recession length to validate the simulation was carried out. The present test case was a light-weight ablator exposed to an arc-heated flow which was in strong thermochemical nonequilibrium. First, two-dimensional simulation code of thermal response of ablator including thermal decomposition, surface reaction (nitridation and sublimation) and surface recession is developed. The assumption is set that pyrolysis gas is quasi-one dimension and steady motion. The arc-jet condition was specified according to the 20 kW arc-heated wind tunnel in Kyushu University with the working gas being N_2. By conducting coupled analysis, we can obtain detailed thermal property data (e.g. temperature and density). Moreover, calculation results were compared with measurement data. Calculation results for temperature inside ablator were basically agreed with experimental data. On the other hand, calculation result for surface recession predicted smaller than experimental data.
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奥山 圭一, 金田 照彦, 加藤 純郎, 大矢 洋明
原稿種別: 本文
セッションID: S1904-1-6
発行日: 2010/09/04
公開日: 2017/08/01
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A carbon fiber reinforced plastic (CFRP) has been widely used as a heat shield material in aerospace community. This CFRP will be pyrolyzed if material surface is heated, and a carbonized layer will be formed. The oxidation of carbonized CFRP in atmosphere was found to be divided into the rate-controlled oxidation region and the diffusion-controlled oxidation region. Okuyama developed a new ultra light-weight CFRP that is called LATS. In order to design a lightweight transfer vehicle, this paper describes the thermochemical characteristics (the mass loss characteristics) of the LATS in the diffusion-controlled oxidation region. The LATS can be applied to a heat shield material for the transfer vehicle by these experiments.
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丹野 英幸, 小室 智幸, 佐藤 和雄, 伊藤 勝宏
原稿種別: 本文
セッションID: S1904-2-1
発行日: 2010/09/04
公開日: 2017/08/01
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Aeroheating of an Apollo CM model was measured in the free-piston shock tunnel HIEST. The primary purpose of the measurement was to obtain benchmark data for numerical codes validation under high-enthalpy high-Reynolds number conditions. The model was made of SUS-304 stainless steel and had a diameter of 250mm. The windward surface of the model was equipped with 84 miniature co-axial Chromel-Constantan thermocouples that were manufactured in-house at JAXA. Twelve thermocouples and two Piezo-resistive pressure transducers were also mounted aft on the model and were used to determine the establishment of flow around the model. In this test campaign, heat flux data were measured for angles of attack 0° and 30°. Stagnation enthalpy and stagnation pressure were varied from H_0=4MJ/kg to 21MJ/kg, and from P_0=14MPa to 58MPa, respectively. Aeroheating characteristics were observed with a fully laminar boundary layer and with a transition boundary layer. Measured heat flux was normalized by the product of the Stanton number and the square-root of the Reynolds number for correlation with other wind tunnel results and flight results. The normalized heat flux value did not change remarkably when stagnation enthalpy was changed from H_0=4MJ/kg to 12MJ/kg, implying that the boundary layer flow was usually laminar. However, shots under high enthalpy and high Reynolds number conditions (H_0 over 18MJ/kg and P_0 approximately 50MPa) showed that the measured heat flux was approximately 40% higher than that obtained in other conditions.
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山田 哲哉, 山田 和彦, 國中 均, 川口 淳一郎
原稿種別: 本文
セッションID: S1904-2-2
発行日: 2010/09/04
公開日: 2017/08/01
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Hayabusa Sample Return Capsule (SRC) has accomplished reentry flight directly from the interplanetary-transfer orbit with velocity of about 12 km/s and successfully recovered on June 14, 2010. The SRC is considered to deploy parachute at the altitude of 5 km as planned, while the chute-trigger timer has been carefully set to cover contingency cases due to malfunctions of triggering devises taking account of dispersions of orbital and atmospheric density and errors in the aerodynamic coefficients. All the components separated at the chute-deployment were searched-out based on the landing position of the instrument module.
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中野 英一郎, 佐藤 直樹, 下田 孝幸
原稿種別: 本文
セッションID: S1904-2-3
発行日: 2010/09/04
公開日: 2017/08/01
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This paper shows the preliminary system study of manned spaceship. Low earth orbit mission and moon mission were assumed as reference missions, and based on these missions, system requirement analysis, subsystem study and spaceship concept study were done.
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河野 功
原稿種別: 本文
セッションID: S1904-2-4
発行日: 2010/09/04
公開日: 2017/08/01
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In consideration of logistic support for International Space Station (ISS) after retirement of Space Shuttle, next generation manned space vehicle projects are in progress, for example NASA's ORION that is capsule-type space vehicle same as Apollo return vehicle. JAXA's H-II Transfer Vehicle (HTV) successfully conducted logistic support for ISS in 2009, and a study on capsule-type HTV Return Vehicle (HRV) was started, that includes feasibility study on in-orbit demonstration of some technologies for manned space vehicles to return to the Earth. To realize the vehicles which go to and return from space, the reentry is one of the most important technology. Precise reentry guidance technology to guide the manned vehicle to planned touchdown point is an essential technology for fast recovery and crew safety. This paper shows the recent study on precise reentry guidance and control of capsule-type manned space vehicles, including reference trajectory design, system design and key technologies to realize precise reentry navigation and guidance.
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下田 孝幸, 佐藤 直樹, 中野 英一郎
原稿種別: 本文
セッションID: S1904-2-5
発行日: 2010/09/04
公開日: 2017/08/01
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Following the two big projects, International Space Station and Space Shuttle, new projects are under consideration in many national agencies, especially in NASA, ESA, and JAXA. NASA has been developing ORION in Constellation program, but the new president, Obama changed the original planning. ESA is also considering a new project, and JAXA is discussing strategy of national space development. In any projects under discussion which go to space and return, the reentry should be one of the most important technology, and decelerating decent velocity and eliminate strong impact at landing for crew safety. This paper shows the in-house study for acquiring the method for getting landing impact. The exact simulation of the landing impact is important for realizing the Japanese return space vehicle.
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平木 講儒, 石津 功太, 日高 靖智, 谷川 元章, 井上 昌信
原稿種別: 本文
セッションID: S1904-2-6
発行日: 2010/09/04
公開日: 2017/08/01
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A parafoil is applicable to an earth-returning vehicle as a promising gliding system. At landing flare is a useful way to brake a parafoil. In the present study an appropriate timing of flare was investigated by a simplified dynamic model of parafoil and payload. The optimum height to start flare was 4 m in order to achieve the least kinetic energy. The experimental flight system with parafoil was used to verify the proposed timing of flare.
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原稿種別: 付録等
p.
App4-
発行日: 2010/09/04
公開日: 2017/08/01
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