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 or 0

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
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 or 0

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
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
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 or 0

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
渡邉 力夫 林 浩平 岩尾 正樹 井河 恵大 冨田 信之
出版者
一般社団法人 日本航空宇宙学会
雑誌
宇宙技術 (ISSN:13473832)
巻号頁・発行日
vol.7, pp.45-52, 2008 (Released:2008-10-11)
参考文献数
9

When liquid nitrogen and heated water are mixed in a chamber, pressure increase due to evaporation expansion inside the chamber becomes high enough to generate thrust force for rocket propulsion. This thrust system is safer and environment-friendly compared to conventional rocket engines utilizing combustion process. This new type of rocket engine system is called "Water-Liquid Nitrogen rocket engine system" and it can be used for small payload mission with expected altitude of several kilometers. In this paper, experimentally obtained thrust characteristics are shown and analyzed. As a result, relations between the thrust force and the mixing chamber pressure are clarified. Also, it is found that the present injector can attain only half of the theoretically expected specific impulse due to insufficient mixing efficiency.
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 or 0

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
竹原 勝之 永山 慶一
出版者
一般社団法人 日本航空宇宙学会
雑誌
日本航空宇宙学会誌 (ISSN:00214663)
巻号頁・発行日
vol.64, no.12, pp.353-357, 2016

<p>MCH-101はAgusta Westland社(以降AW社と呼ぶ)のEH101(現AW101)を川崎重工業株式会社が海上自衛隊向けに改修した機体であり,平成18年に海上自衛隊に初号機が納入されてから輸送用ヘリコプタとして運用されている.米国製の機雷捜索・掃海システムをMCH-101に適合させ,近代化したシステムによる機雷捜索・掃海を可能とするために,平成18年度から社内及び官側研究による調査及び研究作業を実施し,平成23年度から製造契約による掃海仕様の設計,製造,試験を開始,平成27年2月に会社で実施する飛行試験による技術確認をすべて完了しMCH-101掃海仕様初号機を納入した.会社で実施した技術確認試験では,システム統合試験で複数装備品を連接した状態で正常に機能することを確認した後,電磁干渉確認,振動確認,飛行性確認等を飛行状態で実施した.本稿では最も近代化された掃海用ヘリコプタであるMCH-101掃海仕様の開発の経緯及び掃海用装備品の概要を紹介する.</p>