著者

土肥 直人 馬場 順昭 高野 博行

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.605, pp.280-288, 2004 (Released:2004-06-30)

参考文献数

8

被引用文献数

1 1

---

This paper presents a new guidance law for a missile with varying velocity against a maneuvering target with a constant acceleration. Since an approximate missile velocity change during boost phase or after thrust cutoff can be calculated, the intercept point can be estimated if the target acceleration is measured. The guidance law presented guides the missile to the point directly. The guidance law is constructed by combining augmented proportional navigation and pure pursuit navigation with some mixture ratio. From some simulations, it is found that the guidance law presented is more effective and has the higher off-boresight ability and the smaller lateral divert requirements than conventional augmented proportional navigation or proportional navigation even if there exist the LOS angle noises.

著者

佐々木 大輔 片山 裕貴 塩崎 友也 岡本 正人

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.68, no.1, pp.24-30, 2020 (Released:2020-02-06)

参考文献数

7

---

A wing of a human-powered airplane is generally constructed with foam, balsa wood, plastic film and CFRP to achieve light-weight structure. Thus, the structure can be bent and deformed easily. The change of the wing shape may cause the performance degradation. In this study, we physically built the deformed wing model to measure the deformation by using 3D scanner. CFD was used to investigate the influence of the deformation of airfoil on aerodynamic performance in cruise condition through the comparison with original shape. As a result, the deformation causes the fluctuation of pressure distribution, and it also deteriorates the aerodynamic coefficient.

著者

佐原 宏典 荒井 康雄

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.64, no.3, pp.145-152, 2016 (Released:2016-06-05)

参考文献数

24

被引用文献数

1

---

This paper proposes a way of quantitative evaluation for a system with design complexity defined by cyclomatic number, coupling, cohesion, scales of system and subsystems, and the number of interface and communication. Though the design complexity would eventually apply to the calculation of reliableness, it essentially enables a comparison between systems. Here, we adopted the design complexity to Japanese microsatellites, and obtained their characteristics and a guideline to improve them. Furthermore, we found a relation between the design complexity and success level of missions accomplished by the microsatellites, i.e. we should have an option to reduce the design complexity in order to increase the success level of a satellite. Thus, the design complexity affects the reliableness in reliability assessment or resource allocation in a project, so that it would establish an applicable reliability assessment specialized for microsatellite, so-called Hodoyoshi Reliability Assessment.

著者

眞庭 知成 花田 俊也 河本 聡美

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.674, pp.83-89, 2010 (Released:2010-03-25)

参考文献数

18

被引用文献数

3 2

---

Since the launch of Sputnik, orbital debris population continues to increase due to ongoing space activities, on-orbit explosions, and accidental collisions. In the future, it is expected that a great deal of fragments will be created by explosions and collisions. Thus, the number of space debris may increase exponentially (Kessler Syndrome). This paper analyzes the Kessler Syndrome using the Low Earth Orbital Debris Environmental Evolutionary Model (LEODEEM) developed at Kyushu University with collaboration from JAXA. The purpose of the study aims at understanding the issues related to space environment conservation. The results provide effective conditions of Active Debris Removal which is one of the space debris mitigation procedures.

著者

土肥 直人 馬場 順昭 高野 博行

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.594, pp.380-387, 2003 (Released:2003-09-26)

参考文献数

10

被引用文献数

1 1

---

This paper deals with a guidance law for a flight vehicle with varying velocity after thrust cutoff. This guidance law is mechanized by combining the proportional navigation and the pure pursuit navigation with the mixture ratio. Since the performance of the guidance law depends on the ratio, the discussion is focused on the determination of the ratio. Finally, the simulation results show that if the LOS angle noises are small, the proposed guidance law is effective even if the missile velocity decreases and has higher off-boresight ability than the proportional navigation.

著者

林 大介 川崎 繁男

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.67, no.1, pp.9-15, 2019 (Released:2019-02-05)

参考文献数

14

被引用文献数

1 1

---

The re-entry capsule tracking system is proposed as a shared/dual-use technology with commercial products. This system has portability, and is not affected by the condition of installed equipment in the capsule. In this paper, the detection performance is described about the tracking area assumed from Hayabusa's achievement. By the experiment using the prototype radar, this system was confirmed to be able to detect more than 90% of the area.

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 (ISSN:13446460)

巻号頁・発行日

vol.56, no.655, pp.391-395, 2008 (Released:2008-08-27)

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

峯岸 正勝 熊倉 郁夫 岩崎 和夫 少路 宏和 吉本 周生 寺田 博之 指熊 裕史 磯江 暁 山岡 俊洋 片山 範明 林 徹 赤楚 哲也

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.594, pp.354-363, 2003 (Released:2003-09-26)

参考文献数

19

被引用文献数

1 2

---

The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) and Kawasaki Heavy Industories, Ltd. (KHI) conducted a vertical drop test of a fuselage section cut from a NAMIC YS-11 transport airplane at NAL vertical drop test facility in December 2001. The main objectives of this program were to obtain background data for aircraft cabin safety by drop test of a full-scale fuselage section and to develop computational method for crash simulation. The test article including seats and anthropomorphic test dummies was dropped to a rigid impact surface at a velocity of 6.1 m/s (20 ft/s). The test condition and result were considered to be severe but potentially survivable. A finite element model of this test article was also developed using the explicit nonlinear transient-dynamic analysis code, LS-DYNA3D. An outline of analytical method and comparison of analysis result with drop test data are presented in this paper.

著者

伊藤 隆 宮島 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.53, no.619, pp.351-357, 2005 (Released:2005-11-09)

参考文献数

16

被引用文献数

2 2

---

Performance of the methane fueled rocket nozzles are numerically investigated using computational fluid dynamics approach. A simple set of chemical reactions and kinetics for methane/oxygen nozzle flow is proposed. The chamber pressure, mixture ratio and size of the nozzle are parametrically changed to study the influence of characteristic rocket engine design parameters on nozzle losses. The amount of dissociation is high when the chamber pressure is low and the kinetic loss becomes dominant compared to the other nozzle losses. The peak specific impulse is achieved at a higher mixture ratio region as the chamber pressure increases. The chemical non-equilibrium flow appears mainly at down stream region of the nozzle throat. The influence of the chemical non-equilibrium effect decreases as the chamber pressure increases. Supersonic chemically reactive gas stays longer in the nozzle as the size of the nozzle become larger and the amount of recombination increases which decreases the kinetic loss. When the chamber pressure is high, the kinetic loss becomes small and the effect of the size of nozzle also becomes small.

著者

河野 功 杢野 正明 鈴木 孝 小山 浩 功刀 信

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.575, pp.432-437, 2001 (Released:2002-04-26)

参考文献数

6

被引用文献数

2 2

---

Engineering Test Satellite-VII (ETS-VII) is a test satellite to perform in-orbit demonstration of autonomous rendezvous docking (RVD) technology, which will be necessary for advanced space activities in the early 21st century. ETS-VII successfully performed the autonomous RVD by unmanned space vehicle for the first time in the world. For an unmanned space vehicle to perform rendezvous to a manned spacecraft, safe approach is needed. So we paid special attention to designing safe approach trajectory. There are other important points for approach trajectory design, for instance, coordination with guidance and control accuracy, performance of navigation sensors, and operability, etc. In this paper, we introduce the points, and show the result of ETS-VII RVD trajectory design.

著者

東 大輔 中村 佳朗

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.589, pp.52-60, 2003 (Released:2003-09-16)

参考文献数

17

被引用文献数

3 3

---

The subsonic flow for a 45 deg-swept delta wing was numerically simulated to see the effects of rotational leading edges on aerodynamic forces. In the present study, part of the cylindrical leading edge can be rotated which extends from x=0.25C to 0.90 C. The computation has been performed at an angle of attack of 20 deg and a Reynolds number of 2.0×104 based on the maximum wing root chord. Under these conditions, the flow is fully separated from the wing surface in the case without leading edge rotation, so that no suction peaks due to leading edge vortices appear over the upper surface of the wing. Consequently, the delta wing will not have an effective vortical lift. In the case of steady rotation, leading edge vortices were produced on the wing in the early stage. However, a gradual drop in lift coefficient occurred as a result of the diffusion of these vortices. By contrast, in the case of unsteady rotation, a pair of leading edge vortices was maintained, so that a higher lift was produced. Consequently, the lift coefficient became more than 40% higher than that of the plain delta wing.

著者

小紫 公也 中川 樹生 大村 俊介 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.624, pp.18-22, 2006 (Released:2006-02-20)

参考文献数

15

---

Main-lobe energy transmission using an optical phased array is proposed. Effects of spatial and temporal coherence of rectangular-symmetric laser arrays on energy transmission performance are evaluated in terms of the main-lobe beam quality factor and the main-lobe energy transmission efficiency. As a result, the efficiency is found independent of the number of laser elements and their spectral broadening, and sensitive to the aperture fill factor. The main-lobe beam quality factor remains constant for any cases.

著者

上野 陽亮 中村 佳朗

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.317-322, 2009 (Released:2009-08-17)

参考文献数

13

被引用文献数

2 1

---

A numerical simulation method taking into account both aerodynamics and flight dynamics has been developed to simulate the flight of a low speed flying object, where it undergoes unsteady deformation. This method can also be applied to simulate the unsteady motion of small vehicles such as micro air vehicles (MAV). In the present study, we take up a bird and demonstrate its flight in the air. In particular the effect of fluid forces on the bird's flying motion is examined in detail, based on CFD×CFD: Computational Fluid Dynamics (CFD) and Computational Flight Dynamics. It is found from simulated results that this bird can generate lift and thrust enough to fly by flapping its wing. In addition, it can make a level flight by adjusting its oscillation frequency. Thus, the present method is promising to study the aerodynamics and flight dynamics of a moving object with its shape morphing.

著者

河野 功 杢野 正明 鈴木 孝 小山 浩 功刀 信

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.578, pp.95, 2002 (Released:2003-08-19)

参考文献数

9

被引用文献数

7 7

---

ETS–VII is a test satellite to perform in-orbit demonstration of autonomous rendezvous docking (RVD) technology, which will be necessary for advanced space activities in the early 21st century. ETS–VII performed three RVD experiment flights, and verified all technical items. ETS–VII demonstrated first autonomous RVD between unmanned vehicles, and remote piloted rendezvous flight position accuracy at docking was about 1cm, and acceleration was less than 1.5mG (low impact docking). In the second RVD experiment flight, ETS–VII detected attitude anomaly and executed disable abort for safety insurance. We present the results and evaluation of three RVD experiment flights in this paper.

著者

小林 修

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.575, pp.419-424, 2001 (Released:2002-04-26)

参考文献数

10

---

This paper discusses a static stability theory for airplanes. The conventional definitions of static stability are neither clear nor systematic. On the basis of these situations, in the first report of this paper, a system of definitions on 6 static stability concepts was proposed, and two concepts of static flight-velocity stability and static angle of attack stability were studied. And in the second report, a concept of static pitch stability was discussed. This third report discusses on the three static stability concepts in sideslip, roll and yaw, and proposes that “dY/dβ<0, ” “dR/dΦ<0” and “dN/dΨ<0” should be used as the fundamental definitions, where R means rolling moment. The general criteria for these static stabilities are deduced from these definitions. From these criteria, “CYβ<0, ” “Clβ/CYβ>0” and “Cnβ>0” are obtained as the stable conditions. Finally, this report represents the whole summary of this paper.

著者

野田 譲 小林 修

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.633, pp.467-475, 2006 (Released:2006-11-20)

参考文献数

2

---

Most airplanes use their ailerons to compensate the lateral displacement deviation from a reference flight-path. This study proposes a method of lateral flight-path control due to the rudder steering under constraint of automatic roll angle hold. This control method is estimated analytically to produce quicker lateral displacement response than the control due to aileron. Then, experiments using a flight simulator are carried out to evaluate the control characteristics on the task of holding the flight path. The pilot’s evaluation results show that, the rudder steering method gives better flying qualities than aileron steering method. Furthermore, as the more practical control measures, the mixture type of method is worked out, which is transferred from aileron steering to rudder steering depending on the lateral displacement deviation from a reference flight-path.

著者

井上 孝祐 上原 進 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.627, pp.168-174, 2006 (Released:2006-05-19)

参考文献数

20

被引用文献数

1 4

---

An experimental study on the energy conversion process of a continuous wave (CW) laser thruster is presented. The effect of the flow parameters on two dominant loss mechanisms of a CW laser thruster was investigated by using a CW CO2 laser with output power of 700W. The laser transmission and radiation from the laser sustained-plasma (LSP) were measured for several flow velocities and pressures, which were independently controlled. CCD camera was employed in order to observe the shape and position of the LSPs. We found that the energy conversion process is optimized when the LSP is in the vicinity of the focal point of the condensing laser beam.

著者

西澤 宇一 亀田 正治 渡辺 安

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.654, pp.315-323, 2008 (Released:2008-08-27)

参考文献数

12

---

The performance of a two-dimensional Mach 1.64 external compression air intake is investigated by computational fluid dynamics. The intake model consists of a 10-degree wedge and a subsonic diffuser. The flow in and around the intake with different configurations of the slit at the diffuser entrance is calculated to examine the effect of the configurations for pressure recovery and stability of the shock system. The numerical results indicate that the natural bleed fairly improves the intake performance at subcritical operation: It improves the maximum pressure recovery and the tolerance of the mass flow rate through the diffuser to guarantee the stability of the shock. The bleed mass flow rate strongly depends on the slit configuration. Large bleed mass flow rate increases the tolerance of the diffuser mass flow rate for the shock stability. However, the presence of the slit provides no gain in efficiency of the intake at supercritical operation.

著者

林 寛 碓井 美由紀 中山 宜典 清水 幸夫 西山 和孝 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.55, no.647, pp.604-611, 2007 (Released:2007-12-27)

参考文献数

21

被引用文献数

1

---

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.

著者

小木曽 望 内海 智仁 室津 義定

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.586, pp.458-465, 2002 (Released:2003-09-02)

参考文献数

12

被引用文献数

1 1

---

This study is concerned with a shape optimum design of a propeller blade operating in a low Reynolds number range, 1.0–2.0×105. The objective is to minimize the power-required under the constraints on the thrust and the angle of attack in terms of chord length and twist angle distributions where the power-required is evaluated by 3-D panel method. The profile drag is also considered in the optimization, because the effect cannot be ignored in a low Reynolds number range. For calculation efficiency, the profile drag coefficient is approximated by higher order polynomials in terms of Reynolds number and angle of attack. The effectiveness of the proposed method is demonstrated by the design of a propeller blade of a human-powered aircraft. Additionally, effect of the profile drag is discussed by comparing the designs with and without considering the profile drag.