Growth of the two‐dimensional mixing layer from a turbulent and nonturbulent boundary layer
Growth of the two‐dimensional mixing layer from a turbulent and nonturbulent boundary layer
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二维混合层从湍流和非湍流边界层的生长
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
B. Latigo
中科院分区：
文献类型：
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作者：
F. Browand;B. Latigo
实验研究了初始边界层对两股流间湍流混合层下游增长的影响。有两种情况被仔细地记录下来;在一种情况下，分离时的边界层是层流，在另一种情况下，一个边界层用绊线做成紊流。当边界层是湍流时，表征混合区厚度的横向长度尺度（λ）增长较慢。在下游400-500初始动量厚度处，增长率向未分离混合层的增长率松弛，但不满足未分离混合层的增长率。当与局部横向厚度成比例时，湍流量的横向分布在超过约800初始动量厚度的距离处达到相同的形式。
The effect of the initial boundary layer upon the downstream growth of the turbulent mixing layer between two streams is studied experimentally. Two conditions are carefully documented; in one case the boundary layers at separation are laminar and in the other case one boundary layer is made turbulent with a trip wire. When the boundary layer is turbulent; the lateral length scale, ϑ, characterizing the thickness of the mixing region, grows more slowly. At 400–500 initial momentum thickness downstream, the growth rate relaxes toward, but does not meet, the growth rate of the untripped mixing layer. The lateral distributions of the turbulence quantities, when scaled with the local lateral thickness, achieve the same form at distances beyond approximately 800 initial momentum thicknesses.