Transport and mixing of density in a continuously stratified shear layer
Transport and mixing of density in a continuously stratified shear layer
复制标题
连续分层剪切层中密度的传输和混合
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
S. Sarkar
中科院分区：
文献类型：
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作者：
H. Pham;S. Sarkar
采用三维直接数值模拟方法研究了高雷诺数非均匀剪切层中主动湍流的标量输运和混合。考虑两种密度分布：（i）两层具有不同密度的均匀流体，即两层情况，以及（ii）连续分层的背景环境，即Jd情况。混合层的演化包括剪切不稳定性、Kelvin-Helmholtz辊的形成、向湍流的过渡、充分发展的主动湍流，以及最后向层流状态衰减。在Jd的情况下，内部重力波携带的动量和能量被观察到传播远离剪切层。虽然在初始演化过程中不同，但当绘制为浮力的函数时，涡流扩散率和混合效率，雷诺数在湍流衰减阶段的稍后时间在两种情况之间取相似的值。在此阶段，混合效率计算的基础上浮标…
Scalar transport and mixing by active turbulence in a high Reynolds number inhomogeneous stratified shear layer are investigated using three-dimensional Direct Numerical Simulation. Two density profiles are considered: (i) two layers of homogenous fluid with different density, namely the two-layer case, and (ii) a continuously stratified background ambient, namely the Jd case. The evolution of the mixing layer includes shear instability, formation of Kelvin–Helmholtz rollers, transition to turbulence, fully developed active turbulence, and, finally, decay toward a laminar state. In the Jd case, internal gravity waves carrying momentum and energy are observed to propagate away from the shear layer. Although different during the initial evolution, the eddy diffusivity and mixing efficiency when plotted as a function of buoyancy, Reynolds number takes similar values between the two cases later in time during the stage when turbulence decays. During this stage, the mixing efficiency computed based on the buoy...