대한기계학회:학술대회논문집 (Proceedings of the KSME Conference)
- 대한기계학회 2007년도 춘계학술대회B
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- Pages.2868-2872
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- 2007
수동제어 장치를 이용한 3 차원 자동차 모형의 항력감소
Drag Reduction of a Three-Dimensional Car Model Using Passive Control Device
- 발행 : 2007.05.30
초록
In this study, a passive control using a boat-tail device is conducted for a three-dimensional car model in ground proximity. We consider various boat-tails and investigate the mechanism of drag reduction by them. By varying the length and slant angle of boat-tail, we obtain drag reductions up to 40%. From the oil-surface flow visualization and hot-wire measurement, the drag reduction by the boat-tail is characterized by the shear-layer instability and reattachment on the boat-tail, forming a small separation bubble at the upstream part of boat-tail surface, resulting in the delay of main separation and drag reduction. At high slant angles, the flow fully separates and drag is nearly same as that of no control.
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