The behavior of a turbulent front in a stratified fluid: Experiments with an oscillating grid
The behavior of a turbulent front in a stratified fluid: Experiments with an oscillating grid
复制标题
分层流体中湍流前沿的行为：振荡网格实验
DOI：
10.1029/jc092ic05p05329
复制
发表时间：
1987
影响因子：
--
通讯作者：
Soon
中科院分区：
文献类型：
--
作者：
F. Browand;D. Guyomar;Soon
一个简单的实验室模型利用振荡网格在线性分层流体中产生湍流前沿。使用激光荧光和中性浮力示踪粒子对锋面的运动进行目视研究。当网格附近湍流剧烈时，分层不起作用。正如奥兹米多夫所假设的，随着锋面的传播，垂直尺度会受到分层的限制。前沿的破裂可以在无量纲时间 Nt = 10 处识别。这里形成了一系列侵入周围非湍流流体的层。这些层的垂直尺度也可以使用奥兹米多夫假设来预测。它大约是 Nt = 10 时估计的奥兹米多夫尺度的 7 倍。构成锋面的单个入侵的推进以局部弗劳德数为特征，该数随着入侵的延长而减小。推进机制与入侵湍流端产生的波动密切相关。
A simple laboratory model utilizes an oscillating grid to produce a turbulent front in a linearly stratified fluid. The motion of the front is studied visually using laser fluorescence and neutrally buoyant tracer particles. When the turbulence is vigorous near the grid, stratification has no effect. As the front propagates away, vertical scales become limited by stratification, as postulated by Ozmidov. The break-up of the front can be identified at the nondimensional time Nt = 10. Here a series of layers are formed which intrude into the surrounding nonturbulent fluid. The vertical scale of these layers is also predicted using Ozmidov's postulate. It is approximately 7 times the estimated Ozmidov scale at Nt = 10. The advance of individual intrusions comprising the front is characterized by a local Froude number which decreases as the intrusions lengthen. The mechanism of advance is intimately connected with wave motions produced at the turbulent end of the intrusions.