One-dimensional turbulence: vector formulation and application to free shear flows
One-dimensional turbulence: vector formulation and application to free shear flows
复制标题
一维湍流：矢量公式及其在自由剪切流中的应用
DOI：
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发表时间：
2001
影响因子：
3.7
通讯作者：
Vebjorn Nilsen
中科院分区：
文献类型：
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作者：
A. Kerstein;W. Ashurst;S. Wunsch;Vebjorn Nilsen
一维湍流是一种随机模拟方法，代表速度剖面沿着湍流中的假想视线的时间演变。在本文中，速度被视为一个三分量矢量，在以前的配方涉及一个单一的速度分量。这种泛化允许将压力扰频效应，并提供了一个框架，进一步扩展的模型。基于两个替代的物理图片的压力扰相比较，直接数值模拟的两个时间发展的平面自由剪切流：混合层和唤醒的计算结果。扰动的基础上均分的湍流动能的涡流涡流的基础上产生不太准确的结果比一个计划，最大限度地提高组件间的能量传递在每个涡流，受不变性约束。后者制定捕捉自由剪切流的结构，能量和波动特性，包括被动平流标量的概率密度函数的空间变化的许多功能。这些结果表明，所提出的表示矢量速度演变的一维域上的有效性。
One-dimensional turbulence is a stochastic simulation method representing the time evolution of the velocity profile along a notional line of sight through a turbulent flow. In this paper, the velocity is treated as a three-component vector, in contrast to previous formulations involving a single velocity component. This generalization allows the incorporation of pressure-scrambling effects and provides a framework for further extensions of the model. Computed results based on two alternative physical pictures of pressure scrambling are compared to direct numerical simulations of two time-developing planar free shear flows: a mixing layer and a wake. Scrambling based on equipartition of turbulent kinetic energy on an eddy-by-eddy basis yields less accurate results than a scheme that maximizes the intercomponent energy transfer during each eddy, subject to invariance constraints. The latter formulation captures many features of free shear flow structure, energetics, and fluctuation properties, including the spatial variation of the probability density function of a passive advected scalar. These results demonstrate the efficacy of the proposed representation of vector velocity evolution on a one-dimensional domain.