著者

新井 洋 土井 康明 中島 卓司 陸田 秀実 三好 潤

出版者

社団法人 日本船舶海洋工学会

雑誌

日本船舶海洋工学会論文集 (ISSN:18803717)

巻号頁・発行日

vol.9, pp.55-62, 2009 (Released:2009-10-08)

参考文献数

9

被引用文献数

7

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The objective of the present study is to elucidate the ow mechanism of delaying stall by use of wavy leading edges. Experiments were carried out to examine the effects of variant wavy leading edges attached on NACA0018 section wing of aspect ratio 1.6. The Reynolds number based on the chord length is Rec = 1:38 × 105 for the experiments. For these tests, lift, drag, and moment of wings with and without wavy leading edges were measured in a circular water channel. Flow visualization on the surface of wings was also conducted in order to clarify the eects of the wavy leading edges on the delaying stall. It is found that the wavy leading edges can control ow separation and delay stall, which in turn is good for producing large lift force at poststall angles of attack. Under the same height condition, the short width of wavy protuberance shows good performance of the wings compared with that of the long width. The wavy protuberance located near the wing tip does not enhance hydrodynamic performance.

著者

岡田 義浩 農沢 隆秀 坪倉 誠 中島 卓司

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 (ISSN:21879761)

巻号頁・発行日

vol.80, no.809, pp.FE0009, 2014 (Released:2014-01-25)

参考文献数

14

被引用文献数

1 2

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In order to clarify unsteady flow structure’s behavior that improves vehicle’s high-speed stability during steering input, on-road analysis was conducted. The analysis was conducted on two vehicles’ aerodynamic specifications which were produced by configuring two different shapes from a single vehicle. During high speed driving while steering input in sinusoidal waveform was being applied, these two vehicles were analyzed focusing on the relationships between dynamic movements, unsteady forces affecting on vehicle’s body surface and unsteady behavior of flow structure. As a result, it was clarified that there existed a unsteady behavior of flow structure that aerodynamically control to stabilize vehicle’s steering response motion in vertical and yawing direction. It was also clarified that this aerodynamic force that control to stabilize vehicle’s steering response motion was caused by behaviors of flow structure beside body just behind front tire which reduced and expand its vertical scale during high-speed driving with steering input. Furthermore, it was shown that this behavior of flow structure was caused by weakening vortex structure which came out and separated from the gap between the upper rear side of the front wheel and the front wheel arch.

著者

中江 雄亮 池田 隼 安木 剛 田中 博 山下 太郎 坪倉 誠 中島 卓司

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.44, no.6, pp.1471-1476, 2013 (Released:2018-01-25)

参考文献数

5

被引用文献数

4

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車両運動時の非定常空気力は操縦安定性向上に有用である.しかし,風洞におけるこれら空気力の計測や実走行における車両周り流れ場の詳細な計測は困難であり未解明な部分が多い.本報では,CFDを用いて空力パーツ追加による車両運動時の非定常空気力の差異に着目し,その発生メカニズムを解明したので報告する.

著者

中島 卓司 伊藤 裕一 貴家 伸尋 池田 真巳 加藤 由博 北山 真司 鬼頭 幸三 郡 逸平 小山 隆太郎 嶋田 喜芳 花岡 雄二 桧垣 竜彦 福田 紘大 山村 淳 李 曄

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.47, no.6, pp.1439-1445, 2016 (Released:2018-01-29)

参考文献数

8

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車両空力CFDの性能評価,特に境界層発達と流れの剥離の予測精度評価に有用な計測データを得るため,剥離点を固定しない緩やかな曲面の上面形状を持つ簡易車両モデルを対象に風洞試験を実施した.流れの剥離を誘起する付加物有無の2条件で,空力6分力と表面圧力,周囲速度場を計測し,各定量値と関連する空力現象を示した.

著者

中島 卓司 濵村 航明 清水 圭吾 平岡 武宜 農沢 隆秀

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.49, no.2, pp.447-452, 2018 (Released:2018-03-27)

参考文献数

8

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本研究では,後端形状が異なる簡易車両模型を対象に接近流の風向角が単発的に時間変化する風洞試験を行い,特に空気抵抗変化を対象に空力現象を調査した.側面後端角部に曲率を有する模型では,風向変化後も空気抵抗変化が続く履歴効果が確認され,その要因は角部の流れの剥離性状変化が風向変化に遅れるためと推察された.

著者

中島 卓司 坪倉 誠 岡田 義浩 農沢 隆秀 溝兼 通矢 土井 康明

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 (ISSN:21879761)

巻号頁・発行日

vol.80, no.818, pp.FE0301-FE0301, 2014 (Released:2014-10-25)

参考文献数

13

被引用文献数

2

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The objective of this study is to investigate aerodynamics and its generating mechanism of a road vehicle in steady-state cornering, which is the most basic cornering condition. The vehicle motion in the steady-state cornering was defined on a frame of reference fixed on the vehicle and it was divided into a rotation around a vertical axis and a sideslip. Then, aerodynamic force generated by each motion and its generating mechanism was discussed. In order to reproduce an effect of the rotational motion, a towing tank experiment was conducted to measure the fluid-dynamic force acting on a one-fifth-scale model of a sedan-type road vehicle. Assuming that the fluid-dynamic forces are expressible as a linear superposition of effects of the rotation and sideslip, first derivatives of the side force and yaw moment with respect to the yaw rate and the lateral velocity were analyzed by a multiple linear regression analysis. From the results of measurement and analysis, it was clarified that the assumption can provide good approximations of the force and the moment within a range of measurement conditions in this study. Regarding the fluid-dynamic side force, the rotation generates a centripetal force of the circular motion and the sideslip generates a force suppressing the slip motion. Regarding the fluid-dynamic yaw moment, the rotation generates a moment suppressing the rotation, and the sideslip generates a moment enhancing the vehicle's slip angle. Aerodynamics of a sedan-type road vehicle was estimated quasi-steadily by multiple regression equations with measured vehicle motion in an on-road test. From this estimation, the effects of both the rotation and the sideslip had the same order of magnitude. This result indicates that the effects of the vehicle's rotational motion have the same level of importance as the effects of the sideslip in vehicle aerodynamics in steady-state cornering.