Z坐标系下分层三维水流数学模型研究

Study on layer-integrated 3D numerical model for water flow in z coordinates

建立了z坐标系下分层三维水流数学模型,避开了在地形突变变换下水平压力梯度计算较大的困难。在任意三角形网格中,通过剖开算子法,将方程剖分为不同子算子,用各自适应的数值解法进行求解。潜坝及斜槽水流的计算结果与实验结果吻合较好,而基于变换的Delft3D模型计算值与试验值相差较大,因此本文的z坐标分层数学模型可以用来计算包括地形突变的三维水流,并具有较高的精度。

A layer-integrated 3D numerical model for water flow model in z coordinates is developed in this paper. The model can avoid error in computing the horizontal pressure gradient force near steep topography when using cr coordinates. The governing equations are split into two successive initial value problems, as convection and dispersion problem. In any arbitrarilytriangle calculation grids, compatible solution methods would be used in various algorithm according to its particular characteristics. The experiment data in shallow dam and skewed slot flow were selected to verify the model. The simulated results are in satisfactory agreement with experimental data, but when using Delft3D model, the computed results have great error with experimental data. Therefore, the z layer-integrated 3D flow model in this paper can be used to simulate the flow hydrodynamics, including steep topography flow.