Finite-volume multi-stage schemes for shallow-water flow simulations

A finite-volume multi-stage (FMUSTA) scheme is proposed for simulating the free-surface shallow-water flows with the hydraulic shocks. On the basis of the multi-stage (MUSTA) method, the original Riemann problem is transformed to an independent MUSTA mesh. The local Lax - Friedrichs scheme is then adopted for solving the solution of the Riemann problem at the cell interface on the MUSTA mesh. The resulting first-order monotonic FMUSTA scheme, which does not require the use of the eigenstructure and the special treatment of entropy fixes, has the generality as well as simplicity. In order to achieve the high-resolution property, the monotonic upstream schemes for conservation laws (MUSCL) method are used. For modeling shallow-water flows with source terms, the surface gradient method (SGM) is adopted. The proposed schemes are verified using the simulations of six shallow-water problems, including the ID idealized dam breaking, the steady transcritical flow over a hump, the 2D oblique hydraulic jump, the circular dam breaking and two dam-break experiments. The simulated results by the proposed schemes are in satisfactory agreement with the exact solutions and experimental data. It is demonstrated that the proposed FMUSTA schemes have superior overall numerical accuracy among the schemes tested such as the commonly adopted Roe and HLL schemes. Copyright (c) 2007 John Wiley & Sons, Ltd.