円筒に沿った乱流における対抗制御を用いた抵抗低減の直接数値計算

抄録

Opposition controlled fully developed turbulent flows along a thin cylinder are performed by means of direct numerical simulations. An influence of cylinder curvature on the skin-friction drag reduction effect by the classical opposition control (i.e., the radial velocity control) is mainly investigated. The curvature of cylinder affects the statistics of the flow; however, the control effect in the small curvature case is similar to that in channel flow. For large curvature, the drag is reduced even though the detection plane is located away the wall surface. The reduction rates of the present cases are larger than those in the channel flow.