文献一覧: jwe : 日本風工学研究会誌 (雑誌)

1 0 0 0 フォークボールの不思議? (沈む魔球フォークボールの空気力学)

著者: 溝田武人久羽浩幸大原慎一郎岡島厚
出版者: 一般社団法人日本風工学会
雑誌: JWE : 日本風工学研究会誌 (ISSN:09121935)
巻号頁・発行日: vol.70, pp.27-38, 1997-01-31
参考文献数: 9
被引用文献数: 11 4

Aerodynamic behavior of forkball and fastball are studied in a stand point of fluid dynamic research. The fastball rotates in backspin and aerodynamic lift force acts on it is toward upward by Magnus effects. This lift force is the same magnitude with gravity force for good fastball. As a result, the fastball trajectory is nearly straight toward homebase after detaching pitcher's finger. The other hand, good forkball spins around vertical axis. In this case, less lift force and only the gravity force act on the ball. The flight trajectory of the forkball results in vertically sinking line only by the gravity force and laterally sliding one by side spinning effects in its final stage near the homebase.

2021-03-24 06:15:06
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1 0 0 0 乗用車模型の非定常後流

著者: 高木通俊石原裕二
出版者: 一般社団法人日本風工学会
雑誌: JWE : 日本風工学研究会誌 (ISSN:09121935)
巻号頁・発行日: vol.78, pp.35-38, 1999-01-31
参考文献数: 4

How around an automobile is usually considered as steady phenomenon. Aerodynamic coefficients, the most imponant of which is the drag coefficient, are regarded as constants because of the steady flow around the vehicle body. Them is a thought however, the flow separations and the vortical motions around the body me unsteady and the constant drag coefficient can be obtained as a time averaged value of unsteady forces. The present study has been carried out horn this view point The unsteady wake structure up to 300 Hz of a scale vehicle model was measured using 252 total pressure probes. The measuring system is based on ESP (Electronically Scanned Pressure) sensors, which is very popular in the wind engineering field. The results show the wake of the vehicle model has unsteady structure.