PROPAGATION VELOCITY OF PERTURBATIONS IN TURBULENT CHANNEL FLOW
PROPAGATION VELOCITY OF PERTURBATIONS IN TURBULENT CHANNEL FLOW
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DOI：
10.1063/1.858653
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发表时间：
1993-03-01
期刊：
影响因子：
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通讯作者：
HUSSAIN, F
中科院分区：
文献类型：
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作者：
KIM, J;HUSSAIN, F
从直接数值模拟的湍流通道流获得的数据库进行分析，以提取的速度，涡量和压力波动的传播速度V从它们的时空相关性的流向分量。一个令人惊讶的结果是，除了近壁区域之外，V与大多数通道的局部平均速度大致相同。当y+小于或等于15时，V实际上是常数，这意味着所有流动变量的扰动在壁面附近像波一样传播。在这个区域中，对于速度和涡量扰动，V是中心线速度U（c）的55%，对于压力扰动，V是U（c）的75%。对于速度和涡度扰动，这等于y+ = 15时的U，对于压力扰动，这等于y+ = 20时的U，表明近壁湍流的动力学受y+全等至15-20附近的湍流结构控制。V的尺度依赖性也通过分析带通滤波的流场进行检查。本文包含了关于传播速度的全面文献，这些文献在评估泰勒假设时应该是有用的。试图解释的一些数据在目前的理解有组织的结构。
A database obtained from direct numerical simulation of a turbulent channel flow is analyzed to extract the streamwise component of the propagation velocity V of velocity, vorticity, and pressure fluctuations from their space-time correlations. A surprising result is that V is approximately the same as the local mean velocity for most of the channel, except for the near-wall region. For y+ less-than-or-equal-to 15, V is virtually constant, implying that perturbations of all flow variables propagate like waves near the wall. In this region, V is 55% of the centerline velocity U(c) for velocity and vorticity perturbations and 75% of U(c) for pressure perturbations. This is equal to U at y+ = 15 for velocity and vorticity perturbations, and equal to U at y+ = 20 for pressure perturbations, indicating that the dynamics of the near-wall turbulence is controlled by turbulence structures present near y+ congruent-to 15-20. Scale dependence of V is also examined by analyzing the bandpass-filtered flow fields. This paper contains comprehensive documentation on the propagation velocities, which should prove useful in the evaluation of Taylor's hypothesis. An attempt has been made to explain some of the data in terms of the current understanding of organized structures.