Flows simulation in complex open channel networks using Godunov method

A novel one-dimensional hydrodynamic model for open channel network flows has been developed using the shock-capturing Godunov method in order to avoid the traditional numerical models'incapability of accurately simulating supercritical flows and discontinuous flows. The HLL scheme was used to discretize Saint-Venant equations based on finite volume method, and second-order accuracy in time and space was achieved by the numerical reconstruction technology. Junction flow conditions in the open channel networks were described by the mass conservation, energy conservation and the characteristic equations, which were explicitly solved as the internal boundary conditions for each channel. Channels and junctions could be numbered randomly without requiring any specific numbering method, and they were treated independently. The model has been validated by four classical numerical test cases, showing that it is capable of automatically dealing with flow regime changes and simulating flows in complex river network with good accuracy and stability, which indicates the success of the newly developed model. © 2015, Editorial Board of Journal of Basic Science and Engineering. All right reserved.