Amplitude and wavelength scaling of sinusoidal roughness effects in turbulent channel flow at fixed
Amplitude and wavelength scaling of sinusoidal roughness effects in turbulent channel flow at fixed
复制标题
固定条件下湍流通道流中正弦粗糙度效应的幅度和波长缩放
DOI：
10.1017/jfm.2022.118
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发表时间：
2022
影响因子：
3.7
通讯作者：
Brehm, Christoph
中科院分区：
文献类型：
--
作者：
Ganju, Sparsh;Bailey, Sean C.C.;Brehm, Christoph
对光滑壁上的不可压缩湍流通道流和恒定的不同正弦壁粗糙度配置进行直接数值模拟。通过这些关系，我们能够折叠和/或对齐某些流量的峰值，从而捕获表面粗糙度对湍流的影响，即使在近壁区域也是如此。剪切层缩放支持这样的假设：粗糙壁上的湍流中产生湍流动能的物理机制很大程度上受到剪切层及其与粗糙度元素相互作用的影响。最后，开发了一个半经验模型来预测压力和表面摩擦阻力对粗糙度元素的贡献，纯粹基于其几何参数和相应的剪切层速度尺度。
Direct numerical simulations are performed for incompressible, turbulent channel flow over a smooth wall and different sinusoidal wall roughness configurations at a constant . With these relations, we are able to collapse and/or align peaks for some flow quantities and, thus, capture the effects of surface roughness on turbulent flows even in the near-wall region. The shear-layer scaling supports the hypothesis that the physical mechanisms responsible for turbulent kinetic energy production in turbulent flows over rough walls are greatly influenced by the shear layer and its interaction with the roughness elements. Finally, a semiempirical model is developed to predict the contribution of pressure and skin friction drag on the roughness element based purely on its geometric parameters and the corresponding shear-layer velocity scale.