Turbulent flow over a long flat plate with uniform roughness
Turbulent flow over a long flat plate with uniform roughness
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粗糙度均匀的长平板上的湍流
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
D. Chung
中科院分区：
文献类型：
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作者：
D. Pullin;N. Hutchins;D. Chung
本文研究了具有均匀粗糙度（k_s/v）的长L平板在均匀自由速度U_∞下的湍流边界层流动，探讨了在大Re_L <$U_∞L/v下的两种不同极限的物理行为：k_s/L固定的完全粗糙壁流动和Re_k <$U_∞k_s/v固定的长板极限。对于完全粗糙极限，不仅阻力系数C_D与Re_L无关，而且可以找到一个只与k_s/x有关的普遍的表面摩擦系数C_f和标准化边界层厚度δ/k_s，其中x是下游距离。在长板极限下，当Re_L很大时，流动以依赖于Re_k的速率变得渐近光滑。与风洞和现场数据进行了比较。
For turbulent boundary-layer flow under a uniform freestream speed U∞ over a plate of length L, covered with uniform roughness of nominal sand-grain scale k_s, the physical behaviors underlying two distinguished limits at large Re_L≡U∞L/ν are explored: the fully rough wall flow where k_s/L is fixed and the long-plate limit where Re_k≡U∞k_s/ν is fixed. For the fully rough limit it is shown that not only is the drag coefficient C_D independent of Re_L but that a universal skin-friction coefficient C_f and normalized boundary-layer thickness δ/k_s can be found that depends only on ks_/x, where x is the downstream distance. In the long-plate limit, it is shown that the flow becomes asymptotically smooth at huge Re_L at a rate that depends on Re_k. Comparisons with wind-tunnel and field data are made.
影响因子：
3.7
作者：
I. Castro
通讯作者：
I. Castro