Numerical simulation of 2-D shallow-water flow on irregular grids

A numerical model for solving the 2-D shallow-water flow on irregular grids is described. The model based on finite-wlume method adopts the Roe's approximate Riemann solver to deal with the advection terms in the shallow-water equations. A bilinear approximation for the topography in a discrete cell is introduced to preclude the restrictions on the Roe's scheme duo to bed slope. And a modified MUSQ, technique is combined to obtain an increased accuracy. Instead of unilateral difference method,the least square method is used to find the gradient of the primitive variables so that irregular grids can be used. The results of several examples show that the model is capable of treating discontinuities and flow transients,and is good accuracy as well as performance for different applications.