Laboratory observations of shear-layer instability in a stratified fluid
Laboratory observations of shear-layer instability in a stratified fluid
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分层流体中剪切层不稳定性的实验室观察
DOI：
10.1007/bf02188312
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发表时间：
1973
影响因子：
4.3
通讯作者：
C. Winant
中科院分区：
文献类型：
--
作者：
F. Browand;C. Winant
研究了不同盐度和流速的两股水流之间的剪切层中的不稳定性和向湍流的转变。两股流之间的粘性层比扩散层厚15-18倍。当初始层Richardson数较低时，与均匀情况下一样，这种不稳定性将剪切层涡度组织成离散的团块。相似之处到此为止。均匀的剪切层通过相邻的垂直结块(涡旋配对)继续增长。在层状剪切层中，配对过程完全停止，涡量沿界面重新分布。这种重新分布会产生界面波。界面波和残余湍流最终衰减，剪切流接近层流状态。
Instability and transition to turbulence is studied in a shear layer between two streams of different salinities and velocities. The viscous layer between the two streams is 15–18 times thicker than the diffusion layer. When the initial layer Richardson number is low, the instability organizes the shear-layer vorticity into discrete lumps as in the homogeneous case. Here the similarity ends. The homogeneous shear layer continues to grow by the combination of neighboring vertical lumps (vortex pairing). In the stratified shear layer, the pairing process is stopped completely, and the vorticity is redistributed along the interface. This redistribution generates interfacial waves. The interfacial waves and the residual turbulence eventually decay, and the shear flow approaches a laminar state.