Application of a model of internal hydraulic jumps
Application of a model of internal hydraulic jumps
复制标题
内部液压跳跃模型的应用
DOI：
10.1017/jfm.2017.646
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发表时间：
2018
影响因子：
3.7
通讯作者：
Carter, G. S.
中科院分区：
文献类型：
--
作者：
Thorpe, S. A.;Malarkey, J.;Voet, G.;Alford, M. H.;Girton, J. B.;Carter, G. S.
由Thorpe和Li（J. Fluid Mech.，Vol.758，2014，pp.94 -120），其预测了在水平刚性底部上的连续分层层的流动中可能发生静止湍流水力跃变的条件，并将其结果应用于在海洋中的几个位置处进行的观测，并将其结果与之进行比较。该模型确定了两个位置在萨摩亚通道的水力跳跃应该发生，并在流动的结构变化确实观察。该模型预测的变化幅度和观察到的模式2的形式的过渡。湍流动能耗散的预测也与观测结果一致。一个位置提供了一个特别明确的持续水跃的例子。它的形式是一个390米厚、3.7公里长的混合层，经常发生密度反转，被大约200米相对快速移动的稠密水与海床隔开，从而揭示了以前未知的深海内部水跃结构。对亚丁湾红海外流的预测相对不确定。现有的数据和模型预测，不提供强有力的支持，存在的水跃。然而，在地中海外流，模型和数据都表明存在水跃。
A model devised by Thorpe & Li (J. Fluid Mech., vol. 758, 2014, pp. 94–120) that predicts the conditions in which stationary turbulent hydraulic jumps can occur in the flow of a continuously stratified layer over a horizontal rigid bottom is applied to, and its results compared with, observations made at several locations in the ocean. The model identifies two positions in the Samoan Passage at which hydraulic jumps should occur and where changes in the structure of the flow are indeed observed. The model predicts the amplitude of changes and the observed mode 2 form of the transitions. The predicted dissipation of turbulent kinetic energy is also consistent with observations. One location provides a particularly well-defined example of a persistent hydraulic jump. It takes the form of a 390 m thick and 3.7 km long mixing layer with frequent density inversions separated from the seabed by some 200 m of relatively rapidly moving dense water, thus revealing the previously unknown structure of an internal hydraulic jump in the deep ocean. Predictions in the Red Sea Outflow in the Gulf of Aden are relatively uncertain. Available data, and the model predictions, do not provide strong support for the existence of hydraulic jumps. In the Mediterranean Outflow, however, both model and data indicate the presence of a hydraulic jump.