Vortex structures and microfronts
Vortex structures and microfronts
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涡旋结构和微阵面
DOI：
10.1063/1.868293
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发表时间：
1994
影响因子：
4.6
通讯作者：
L. Mahrt
中科院分区：
文献类型：
--
作者：
T. Gerz;J. Howell;L. Mahrt
本文研究了均匀湍流中热微锋与相干涡结构之间的关系。湍流是由弱分层流中的平均剪切产生的。该数据集通过直接数值模拟生成，提供了高分辨率的波动速度和温度的瞬时三维场（每个场1603个数据点）。垂直倾斜的大尺度马蹄涡由于平均剪切速率的拉伸和旋转而发展，这也会发生在中性分层流中。在均匀剪切流中，倾斜平面上的结构以相等的概率向上和向下定向，并且被称为“头向上”和“头向下”马蹄形涡流。涡度结构的采样在这些地区的流动，最强的相干局部温度梯度发生。将合成采样字段。结果表明，微锋是由马蹄涡腿间的局部外流引起的。个...
This study addresses the relationship between thermal microfronts and coherent vortex structures in homogeneous turbulence. The turbulence is created by mean shear in a weakly stratified flow. The data set is generated by direct numerical simulation providing highly resolved instantaneous three‐dimensional fields of fluctuating velocity and temperature (1603 data points for each field). Vertically inclined large‐scale horseshoe vortices develop due to stretching and rotation by the mean shear rate, as would also occur in neutrally stratified flow. In a homogeneous shear flow, the structures on the tilted plane are oriented both upward and downward with equal probability, and are referred to as ‘‘head‐up’’ and ‘‘head‐down’’ horseshoe eddies. Vorticity structures are sampled in those regions of the flow where the strongest coherent local temperature gradients occur. The sampled fields are composited. It is found that the microfronts are caused by the local outflow between the legs of the horseshoe eddies. A...