Streaming vorticity flux from oscillating walls with finite amplitude
Streaming vorticity flux from oscillating walls with finite amplitude
复制标题
来自具有有限振幅的振荡壁的流涡通量
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
Jain
中科院分区：
文献类型：
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作者：
Jiezhi Wu;X. H. Wu;Jain
如何描述运动壁面涡量的产生是一个长期存在的问题。本文从基础层面探讨相关问题。首先，它表明，“由于壁加速涡通量”的概念可以最好地理解以下流体粒子在墙上，而不是观察在固定的空间点的流动。当考虑时间平均通量时，这是至关重要的。平均通量必须在壁固定参考系中估计（其中根本没有由于壁加速度引起的通量）;或者，如果使用惯性参考系，广义拉格朗日平均（GLM）也给出相同的结果。然后，对于一些简单但典型的配置，时间平均涡通量从一个有限振幅的谐波振荡壁分析，没有呼吁小扰动。主要结论是，壁面振荡将产生一个附加的平均涡量通量（一种完全非线性的流动效应），这是部分的。
How to describe vorticity creation from a moving wall is a long standing problem. This paper discusses relevant issues at the fundamental level. First, it is shown that the concept of ‘‘vorticity flux due to wall acceleration’’ can be best understood by following fluid particles on the wall rather than observing the flow at fixed spatial points. This is of crucial importance when the time‐averaged flux is to be considered. The averaged flux has to be estimated in a wall‐fixed frame of reference (in which there is no flux due to wall acceleration at all); or, if an inertial frame of reference is used, the generalized Lagrangian mean (GLM) also gives the same result. Then, for some simple but typical configurations, the time‐averaged vorticity flux from a harmonically oscillating wall with finite amplitude is analyzed, without appealing to small perturbation. The main conclusion is that the wall oscillation will produce an additional mean vorticity flux (a fully nonlinear streaming effect), which is partial...