Abstract Opposition controlled fully developed turbulent flow along a thin cylinder is analyzed by means of direct numerical simulations. The influence of cylinder curvature on the skin-friction drag reduction effect by the classical opposition control (i.e., the radial velocity control) is investigated. The curvature of the cylinder affects the uncontrolled flow statistics; for instance, skin-friction coefficient increases while Reynolds shear stress (RSS) and turbulent intensity decrease. However, the control effect in the case of a small curvature is similar to that in channel flow. When the curvature is large, the maximum drag reduction rate decreased. However, the optimal location of the detection plane is the same as that in a flat plate. Further, the drag reduction effect is achieved even on a high detection plane where the drag increases in the flat plate. Although a difference in the drag reduction effect can be observed with a change in the curvature, its mechanism considered in this analysis based on the transport of the Reynolds stress is similar to that of the flat plate.

中文翻译：

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薄圆柱湍流中曲率对减阻的影响

摘要 通过直接数值模拟分析了沿薄圆柱体的对立控制的完全发展湍流。研究了圆柱曲率对经典反向控制（即径向速度控制）的表面摩擦减阻效果的影响。圆柱体的曲率影响不受控制的流动统计；例如，当雷诺剪切应力 (RSS) 和湍流强度降低时，皮肤摩擦系数增加。但是，在小曲率情况下的控制效果与通道流中的控制效果相似。当曲率较大时，最大减阻率降低。然而，检测平面的最佳位置与平板中的相同。更多，即使在平板中阻力增加的高检测平面上也能实现减阻效果。虽然随着曲率的变化可以观察到减阻效果的差异，但在基于雷诺应力传递的分析中考虑的其机制与平板的机制相似。