平面二维非均匀沙数值模拟方法

摘要

In this paper, a plane 2-D mathematical model for unsteady flow and non-homogeneousrnsediment movement based on grid and splitting principle is established. The flow equationrntogether with diffusion equation for suspension have been split into three parts includingrnconvection, diffusion and propagation, and corresponding methods for calculation are proposed.rnThe numerical calculation shows that the process of river bed erosion can be preciselyrnsimulated by using this method.%本文基于三角形网格划分，从平面二维水流泥沙的基本方程及基础理论出发，针对方程的基本特性采用剖开算子方rn法，将水流运动方程及悬移质扩散方程剖分成对流、扩散及传播三部分并提出了各自相应的计算方法；连续方程采用有限体rn积法进行计算，保证了水量的守恒；泥沙计算中采用平面二维非均匀沙水流挟沙力公式，并着重对河床冲刷过程中悬移质含rn沙量、级配，床沙级配等沿时空变化特性进行了计算分析，模拟了概化河道中床沙抗冲层的形成过程.数值实验表明，该方法rn边界符合良好，计算量小，能准确地模拟河床冲刷过程.