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Vertical 2D Modeling of Free Surface Flow with Hydrodynamic Pressure Using SIMPLE Arithmetic in σ coordinates

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海洋工程：英文版 2004年第1期18卷 79-92页

作者：吴修广沈永明郑永红 State Key Laboratory of Coastal and Offshore Engineering Guangzhou Institute of Energy Conversion

A numerical model for shallow water flow has been developed based on the unsteady Reynolds-averaged Navier-Stokes equations with the hydrodynamic pressure instead of hydrostatic pressure assumption. The equations are transformed into the σ-coordinate system and the eddy viscosity is calculated with the standard k-ε turbulence model. The control volume method is used to discrete the equations, and the boundary conditions at the bed for shallow water models only include vertical diffusion terms expressed with wall functions. And the semi-implicit method for pressure linked equation arithmetic is adopted to solve the equations. The model is applied to the 2D vertical plane flow of a current over two steep-sided trenches for which experiment data are available for comparison and good agreement is obtained. And the model is used to predicting the flow in a channel with a steep-sided submerged breakwater at the bottom, and the streamline is drawn.

关键词： free surface flow hydrodynamic pressure kinematic boundary condition σ-coordinate SIMPLE arithmetic

A novel dynamic coherent eddy model and its application to LES of a turbulent jet with free surface

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Science China(Physics,Mechanics & Astronomy) 2010年第9期53卷 1671-1680页

作者： LU Jun,TANG HongWu,WANG LingLing & PENG Feng College of water conservancy of hydro-power engineering,Hohai University,Nanjing 210098,China 1. College of water conservancy of hydro-power engineering Hohai University Nanjing 210098 China

We has developed a novel dynamic coherent eddy model,in which the coherent structure-Q criterion introduced by Hunt et al(1988)-is taken into account in the subgrid-scale turbulent viscosity based on the eddy viscosity *** proposed method is to combine the resolved-scale velocity-gradient tensor in the classical Smagorinsky model with Q criterion weighted.A kind of dynamic procedure which was averaged in a general process at temporal direction based on the autocorrelations of the characteristic resolved scales of turbulence was taken for the coefficient of subgrid *** model is implemented in the σ-coordinate and the filtered Navier-Stokes equations are solved by the operator splitting *** validation was explored to 2-D turbulent slot jet both in ambient environment and in regular *** prediction of the present model was compared with the experiment data,including the averaged velocity profiles,the velocity fluctuations and the Reynolds *** model performance is shown to be satisfactory.

关键词： LES subgrid-scale modeling σ-coordinate turbulent jet

Numerical Study of Flow Near River Outlet in Namtso Lake

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Journal of Southwest Jiaotong University(English Edition) 2008年第4期16卷 404-413页

作者：德吉玉珍 Jarle Berntsen School of Science Tibet University Department of Mathematics University of Bergen

A river plume dynamics analysis was made in Namtso Lake by using a sigma coordinate non-hydrostatic numerical ocean model, the Bergen Ocean Model. Simulations were carried out by hydrostatic and non-hydrostatic models with horizontal resolution of 5.00 m, 2.50 m and 1, 25 m, respectively. The simulation results for the homogeneous lake are robust to the grid size, and the non-hydrostatic pressure effect is not important in this ease. For the stratified case, the results are sensitive to both the grid size and non-hydrostatic pressure corrections.

关键词： Non-hydrostatics River plume Numerical ocean model σ-coordinate Stratified