Non-hydrostatic versus hydrostatic modelings of free surface flows  

作　　者：张景新 SUKHODOLOV Alexander N. 刘桦 

机构地区：[1]MOE Key Laboratory of Hydrodynamics,Shanghai Jiao Tong University [2]Key Laboratory of Estuarine and Coastal Engineering,Ministry of Transport [3]School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University [4]Department of Ecohydrology,Institute of Fresh-water Ecology and Inland Fisheries [5]MOE Key Laboratory of Hydrodynamics,Shanghai Jiaotong University

出　　处：《Journal of Hydrodynamics》2014年第4期512-522,共11页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(Grant No.10702042);the Non-profit Industry Financial Program of MWR(Grant No.201401027);the National Key Basic Research Development Program of China(973 Program,Grant No.2014CB046200);supported by the DeutscheForschungsgemeinschaft (Grant No. DFG SU 405/3,SU 405/4)

摘　　要：The hydrodynamics of geophysical flows in oceanic shelves, estuaries, and rivers are often studied by solving shallow water equations under either hydrostatic or non-hydrostatic assumptions. Although the hydrostatic models are quite accurate and cost-efficient for many practical applications, there are situations when the fully hydrodynamic models are preferred despite a larger cost for computations. The present numerical model is implemented by the finite volume method （FVM） based on unstructured grids. The model can be efficiently switched between hydrostatic and non-hydrostatic modules. The case study shows that for waves pro- pagating along the bar a criterion with respect to the shallowness alone, the ratio between the depth and the wave length, is insufficient to warrant the performance of shallow flow equations with a hydrostatic approach and the nonlinearity in wave dynamics can be better accounted with a hydrodynamic approach. Besides the prediction of the flows over complex bathymetries, for instance, over asymmetrical dunes, by a hydrodynamic approach is shown to be superior in accuracy to the hydrostatic simulation.The hydrodynamics of geophysical flows in oceanic shelves, estuaries, and rivers are often studied by solving shallow water equations under either hydrostatic or non-hydrostatic assumptions. Although the hydrostatic models are quite accurate and cost-efficient for many practical applications, there are situations when the fully hydrodynamic models are preferred despite a larger cost for computations. The present numerical model is implemented by the finite volume method （FVM） based on unstructured grids. The model can be efficiently switched between hydrostatic and non-hydrostatic modules. The case study shows that for waves pro- pagating along the bar a criterion with respect to the shallowness alone, the ratio between the depth and the wave length, is insufficient to warrant the performance of shallow flow equations with a hydrostatic approach and the nonlinearity in wave dynamics can be better accounted with a hydrodynamic approach. Besides the prediction of the flows over complex bathymetries, for instance, over asymmetrical dunes, by a hydrodynamic approach is shown to be superior in accuracy to the hydrostatic simulation.

关 键 词：HYDROSTATIC NON-HYDROSTATIC TVD scheme non-orthogonal grid 

分 类 号：O35[理学—流体力学]