Reynolds stress and vortical structure in a uniformly sheared turbulence
Reynolds stress and vortical structure in a uniformly sheared turbulence
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DOI：
10.1143/jpsj.61.4400
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发表时间：
1992-12
影响因子：
1.7
通讯作者：
S. Kida;Mitsuru Tanaka
中科院分区：
文献类型：
--
作者：
S. Kida;Mitsuru Tanaka
采用Navier-Stokes方程的直接数值模拟和快速畸变分析方法，研究了均匀剪切湍流中雷诺数剪应力的空间结构。观察到许多不同形状的薄涡管从随机初速度场发展而来。雷诺兹剪切应力也具有管状结构，并且在沿展向排列的对向旋转涡之间的值特别大，这是之前通过条件平均（Adrian & Moin 1988）所揭示的。正如在实验室实验中观察到的那样，湍流动能随时间呈指数增长。快速变形分析表明，只有湍流速度与平均应变的线性相互作用才能产生管状结构，使速度场为高斯场。有组织的结构并不一定意味着速度场的非高斯性。
The spatial structure of the Reynolds shear stress in a uniform shear turbulence is investigated by the direct numerical simulation of Navier-Stokes equations and by the rapid distortion analysis. It is observed that many thin vortex tubes of various shapes develop from a random initial velocity field. The Reynolds shear stress also has tube-like structure and takes especially large values between pairs of counter rotating vortices aligned in the spanwise direction as was revealed before by conditional averaging (Adrian & Moin 1988). The turbulent kinetic energy increases exponentially in time as has been observed in laboratory experiments. The rapid distortion analysis demonstrates that the tube-like structure can be created only through the linear interaction of the turbulent velocity with the mean strain, leaving the velocity field be Gaussian. The organized structure does not necessarily imply non-Gaussianity of the velocity field.