The shark-skin-inspired riblets could effectively reduce the turbulence wall-skin friction compared with the smooth surface. Nevertheless, computations of the flow field over riblets in the practical configurations (e.g., airplanes and wind turbines) remain unfeasible for its huge computational cost. In this study, a general strategy for modelling the effects of riblets in turbulent flows is proposed. Riblets are modelled by adopting a slip-boundary condition on the smooth wall. A quantitative relationship between the riblet geometric parameters and the slip length is theoretically built for the first time. This modelling method could greatly reduce grid numbers in the validating procedure by using Large-Eddy Simulation, and the modelling results indicate that the flow fields in logarithmic and wake regions over riblets could be accurately reproduced. Additionally, considering the slip-boundary model is not capable of reproducing the near-wall flow, a simplified calculating method is developed.

中文翻译：

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湍流中肋条模拟的通用模型

与光滑表面相比，受鲨鱼皮启发的罗纹可以有效减少湍流壁与皮肤的摩擦。然而，在实际配置（例如，飞机和风力涡轮机）中计算肋条上的流场由于其巨大的计算成本而仍然不可行。在这项研究中，提出了一种模拟湍流中肋条效应的一般策略。通过在光滑壁上采用滑动边界条件来模拟 Riblets。首次在理论上建立了沟槽几何参数与滑移长度之间的定量关系。这种建模方法通过使用大涡模拟可以大大减少验证过程中的网格数，建模结果表明，可以准确再现沟槽上方对数区和尾流区的流场。此外，考虑到滑移边界模型不能再现近壁流动，开发了一种简化的计算方法。