A numerical approximation for modeling morphological behavior in open channels is presented in this paper. The scheme is based on Godunov-type finite volume method which is preferred for its conservation preserving ability. The Saint Venant equations for river flow coupled with sediment continuity form the governing system of equations. Flux computation through cell interfaces is computed by Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver method at each time step. Second-order temporal and spatial accuracy is confirmed by employing Henn’s method and high-order reconstruction technique with limited gradient, respectively. The coupled model is able to handle discontinuities in surface water flow and bed profiles, and prevent spurious oscillations in all cases. A hydrostatic reconstruction technique is used to handle wet-dry fronts and avoid negative water depths and unphysical high velocities in complex domains. A modification in surface gradient method satisfies the well-balancing between flux computations of momentum and slope-source terms. Comparison of model-results for various tests with their analytical and experimental solutions shows that our numerical scheme is robust in simulating steady and unsteady flows over a various domains.

• Khawar Rehman(Ph.D Candidate, Member., Department of Civil and Environmental Engineering, Hanyang University)
• Yong-Sik Cho(Member. Professor, Department of Civil and Environmental Engineering, Hanyang University) Corresponding Author