著者

大島 伸行

巻号頁・発行日

2023

著者

鬼頭 幸三 大島 伸行 山本 誠 セベン シモネ

出版者

東京大学生産技術研究所

雑誌

生産研究 (ISSN:0037105X)

巻号頁・発行日

vol.61, no.1, pp.22-25, 2009

---

基礎検討として単純な車体外形形状と平坦床下形状をもつASMO車体について, LESと標準k-εモデルによる解析解を比較し, 車両の空力開発におけるLESの有用性を示した.実験による直接検証が困難な実用的な問題において, 標準スマゴリンスキーモデルによるLES解析解の実用的な評価方法を提案した.この評価方法によって複雑な車体外形形状と床下形状をもつV50車体の流れ場に関するLES解析解を評価した.[本要旨はPDFには含まれない]

著者

高橋 裕介 小池 太輝 大島 伸行

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2018, 2018

---

<p>Aerodynamic heating of an inflatable reentry vehicle, TITANS, which is one of the innovative reentry technologies, was investigated using a tightly coupled approach involving computational fluid dynamics and structure analysis. A strong shock wave at the front and a wake structure behind the TITANS vehicle were clarified. It was indicated that thermochemically nonequilibrium flow appears for a case of the peak heating altitude in the trajectory of mission. A heat flux distribution due to high temperature gradient near deformed surface was uncovered. The heat flux at the capsule part of the TITANS vehicle increased, while that on the membrane decreases. This is because the shock wave formation changed by the membrane deformation. In addition, it was indicated that wrinkles on the membrane formed by the deformation causes increase in heat flux.</p>

著者

武藤 昌也 坪倉 誠 大島 伸行

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集B編 (ISSN:18848346)

巻号頁・発行日

vol.77, no.775, pp.781-792, 2011 (Released:2011-03-25)

参考文献数

14

被引用文献数

1

---

Flow characteristics and fluid force on a sphere rotating along with axis perpendicular to mean air flow were investigated using Large Eddy Simulation (LES) at two different Reynolds numbers Rep of 1.0×104 and 2.0×105. As a result of simulation, opposite flow characteristics around the sphere and displacement of the separation point were visualized depending on the Reynolds number even though rotation speed according to the Reynolds number is the same. When the sphere rotates at some specific rotation velocity and at Rep = 1.0×104, flow characteristics agree with the flow field explained in the Magnus effect. While sphere rotates at the same rotation velocity while increasing Rep to 2.0×105, separation point moves in opposite direction and wake appears in the different direction. The reason of the negative Magnus force was discussed in terms of the boundary layer transition on the surface.

著者

岸田 耕一 金子 雄大 大島 伸行 永田 晴紀

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.76, no.765, pp.789-794, 2010-05-25

---

This paper investigates a thermal-fluid dynamics of CAMUI (Cascaded Multistage Impinging-jet) type hybrid rocket developed in Hokkaido University by using a large eddy simulation of turbulence. The performance of the hybrid rocket is sensitive to the changing shape of its chamber. To clarify this effects, numerical simulations were conducted using measured shapes. The results show the flow structures such as impinging fountain flow depending on the shapes at different burning time. Thease structures generate the particular heat flux distributions on the surface.