Depth-Averaged Hydrodynamic Model in Curvilinear Collocated Grid

A two-dimensional (2D) depth-averaged model of turbulent flows has been developed in a boundary-fitted curvilinear coordinate system. Based on the finite-volume method (FVM), the convection terms are discretized by the Roe's scheme of second-order accuracy, as well as the Power-law scheme. The governing equations are solved in a collocated grid system by the efficient fractional two-step implicit algorithm that is regarded superior to the SIMPLEC algorithm. The “time marching” technique has been used to obtain a steady-state solution as a limiting case. The new model has been applied to several problems including pure convection of a sharp step profile, side discharge into an open channel, flow in a meandering channel, and flow in a Parshall flume with supercritical outflow. Comparison with the available data shows that the model is efficient and robust.