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バドミントンには,オリンピック正式種目としての「競技」である面と,ラケットとシャトルコックさえあれば小さい子どもからお年寄りまで,誰でも気軽に楽しめる「遊戯」としての一面も併せ持っており,非常に奥深く面白いスポーツである。シャトルコックの運動は,スマッシュ時に旅客機の離陸速度並みの250～300km/hにも達するが,激しい減速特性によりコート内で最終速度は0近くなる等,広範囲な速度変化に特徴がある。シャトルコックを航空工学的視点から見ると,非常に大きな抵抗係数を有する飛行体と捉えることができ,その抵抗発生のメカニズムや飛行特性の解明等,工学的に興味の尽きない対象であるが,その空気力学的特性は十分には解明されていない。本論文では,身近にある遊具としてバドミントンで使用されるシャトルコックを取り上げ,筆者らがこれまでに解明してきた水鳥球の空気力学的特性に加え,樹脂製シャトルコック対する静的空気力測定,静圧・総圧測定及び流れ場の可視化を実施することにより,両シャトルコック間の空気力学的特性の相違点を明らかにした。また,風洞実験から得られた空力係数を基に,競技における代表的打法であるスマッシュ及びハイクリアにおけるシャトルコックの軌道解析も実施し,両シャトルコック間の飛行特性の違いについても検討した。

Multi-Utility Spacecraft Charging Analysis Tool (MUSCAT) is a software under development by Kyushu Institute of Technology (KIT) jointly with JAXA. Its numerical engine is a plasma simulator based on particle method. It includes both Particle Tracking method (PT), which simulates flux of electric charge into surface of spacecraft, and Particle In Cell method (PIC) which simulates distribution of space plasma. In order to simulate erosion of on ion engine grid system, not only simulating spatial structure of electric potential but also simulating the flux of various particles into grid system is necessary. Therefore, techniques of MUSCAT are applicable for grid simulation by expanding simulation of charged particles to that of particles including neutral particles. As the initial phase, we conducted trajectory analysis of ion beam for mono-hole and the numerical result is reported., 資料番号: AA0063329009, レポート番号: JAXA-SP-06-019

A two-year plan for the development of the first stage of the JIEDI tool (JAXA Ion Engine Development Initiative 1, JIEDI-1) is proposed. In order to circumvent the heavy calculation cost associated with the three-dimensional analysis of multiple holes, JIEDI-1 focuses on the analysis of only one pair of grid holes. Aside from some new code developments and related research activities by the workshop members, JAXA will support the grid erosion evaluation code, which was developed by Nakano, for the purpose (1) to share a recipe how to produce a grid erosion code, (2) to evaluate the accuracy of the code, and (3) to check the effect of input parameters such as plasma characteristics, neutral particle density, and sputtering/deposition yield. Related technical issues, which are summarized in this paper, are also discussed in the next workshop in January 2008 to complete the development of the first generation of JIEDI tool (JIEDI-1 tool) in 2009., 資料番号: AA0063329010, レポート番号: JAXA-SP-06-019

The Real Time Trajectory Estimation Program (RTEP) is JAXA's system for estimating a satellite's trajectory and thrust acceleration based on the Kalman filter during the Apogee Engine Firing (AEF). RTEP has been used during the AEFs of, ETS (Engineering Test Satellite)-6 (1994), COMETS (Communications and broadcasting Engineering Test Satellite) (1998), DRTS (Data Relay Test Satellite) (2002), OICETS (Optical Inter-orbit Communications Engineering Test Satellite) (2005) and ALOS (Advanced Land Observing Satellite) (2006). This paper presents the overview of RTEP, the results of the estimation using Space network data., 資料番号: AA0063223010, レポート番号: JAXA-SP-06-015