著者
中村 竣 岩本 雄馬 寺本 進 岡本 光司
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.22, pp.94-100, 2023 (Released:2023-12-06)
参考文献数
15

Incoming wakes can induce separated boundary layer instability, and cause performance losses in turbine cascades of a gas turbine. An efficient numerical method that can analyze unsteady incoming wake effects is desirable from practical point of view. In the present study, an extended harmonic balance method (Chebyshev-based harmonic balance, C-HB) is introduced to the analysis of the incoming wake effect on the separated boundary layer. Convection of a one-dimensional wake-like profile and the flow around the flat plate whose front part is replaced by the NACA0012 with the incoming wake at a Reynolds number Re = 92,000 are computed by the C-HB method. The result shows that the C-HB method can resolve the transient phenomenon of wake convection and the associated linear instability of the flow around the blade.
著者
佐原 宏典 渡部 武夫 渡邊 秋人 伊藤 裕明
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.11, pp.15-22, 2012 (Released:2012-01-31)
参考文献数
15
被引用文献数
2 2

This paper reports a development and demonstration of inflatable extension boom in the experiments of the ISAS/JAXA sounding rocket, S-520-25. The inflatable extension boom developed by the authors is the longest in ones with conductive part to work as an electrode for collection of electrons surrounding the rocket. S-520-25 sounding rocket was launched in August 31, 2010, and 5 experiments including an extension of the inflatable boom were conducted. The inflatable extension boom and its system worked very well with no problem to form 4-m-long electrode in space.
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
浅井 圭介 鈴木 一義
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.71, no.9, pp.247-249, 2023-09-05 (Released:2023-09-05)
参考文献数
3

二宮忠八(以下,忠八)は我が国の航空技術の先駆者である.飛行原理発見に至る思考過程を文書に残し,模型飛行機を製作して飛行実証を行ったという点で,忠八は航空技術史上において特別な存在だと言える.忠八考案の有人飛行機が実現することはなかったが,彼が作成した様々な技術資料や自作の模型飛行機が,忠八自身が創建した飛行神社や彼の故郷の八幡浜市の施設に保管されている.二宮忠八の動力飛行研究は当時の最先端を走るものであり.航空宇宙技術遺産の第一号認定に値する技術である.
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
松野 賀宣 菊地 亮太
出版者
一般社団法人 日本航空宇宙学会
雑誌
日本航空宇宙学会誌 (ISSN:00214663)
巻号頁・発行日
vol.71, no.8, pp.221-227, 2023-08-05 (Released:2023-08-05)
参考文献数
22

航空機運航において,到着予定時刻(Estimated Time of Arrival: ETA)の予測精度は,風予測誤差に大きく影響される.本稿では,風予測誤差の影響を緩和し,ETAの予測精度を向上させるため,確率的風予測手法を提案し,巡航速度誘導則に適用する.確率的風予測では,多数の数値気象予報を行うアンサンブル予報を用いて,風を確率的に推定することで,ETAを高精度に予測する.そして,速度誘導則では,所定の許容範囲内で目標の到着時刻を満たす最適速度を決定する.本稿では,数値シミュレーションにより,確率的風予測を適用した速度誘導則の性能及び有効性を評価する.確率的風予測を適用することで,典型的な飛行管理装置に比べ,ETA予測精度が向上し,目標の到着時刻を満たすための不必要な速度変更回数を低減することができるため,航空交通管制による軌道予測性の向上や,燃料消費量の削減効果が期待される.
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
石川 芳男 井上 正史 小宅 康博 山極 芳樹 栗木 恭一
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.41, no.471, pp.205-212, 1993-04-05 (Released:2010-12-16)
参考文献数
9
被引用文献数
1 1

In coming new space age, we will have frequent trips between the ground and mission orbits by large rockets to realize the large projects such as space stations and solar power satellite systems. In such cases a great deal of rocket effluents should be released in the atomosphere. But, its effects on our environment is still unknown, and therefore various studies on these problems are expected. About such environmental problems, some studies were performed which motivated by so called “ionospheric hole” observed when Skylab-I was launched, May 14, 1973. It was certified by later scientific studies that the phenomenon was caused by the chemical reaction between rocket effluents and ionized particles in the ionosphere, by which the electron density of the ionosphere suddenly decreased to about a half values of that in its normal state in the range of about 1, 000km in radius centering about rocket trajectory and it took about 4 hours to recover. In this study, the results of these fundamental studies are applied to the engineering problem, that is, the numerical simulation of the change in electron density in the ionosphere is carried out in consideration of the diffusion of rocket effluents released along arbitrary trajectory in upper atomosphere and their chemical reactions with the ionospheric constituents.