유체기계공업학회:학술대회논문집
- 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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- Pages.199-202
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- 2006
능동제어를 이용한 구의 저항 감소
Active Controls of Flow Over a Sphere for Drag Reduction
초록
The objective of this study is to propose methods of controlling the wake behind a sphere for drag reduction using the suboptimal control theory and surrogate management framework, respectively. The Reynolds numbers considered is 300 at which the base flow is unsteady planar symmetric. Given the cost function defined as the square of the difference between the target pressure (potential-flow pressure) and real flow pressure on the sphere surface, the suboptimal control makes the flow steady axisymmetric and produces drag reduction. Based on the actuation profile from the suboptimal control, the optimal wavy actuation profile is obtained using the surrogate management framework and produces drag reduction.