Author(s): S. Evangelista
Linked Author(s):
Keywords: No Keywords
Abstract: Application of classical methods for the resolution of systems of conservation laws to dam break problems on a mobile bed can encounter difficulties. The required use of a Riemann solver, in fact, often turns out to be quite complicated for multi-phase flow problems. Numerical techniques which avoid the solution of the Riemann Problem in the conventional sense appear, thus, of great utility in these cases. One of these methods is GMUSTA. A two-phase model proposed by Greco et al. (2008) has been here used to describe the morphodynamics of the problem. The eigenstructure of the system of non-linear hyperbolic equations is not completely available since the calculation is very complex and costly. The GMUSTA method has been thus selected for the numerical implementation of the model. The interesting feature of GMUSTA is its capability of achieving the high accuracy of upwind schemes while keeping the simplicity of centered schemes. It is, in fact, a multi-stage centered-scheme which calculates the intercell fluxes as a weighted average of the Lax-Friedrichs and Lax-Wendroff fluxes (GFORCE flux), passing through a predictor and a corrector step (MUSTA approach). Simulations of dam break sample cases have been performed using a 1-stage GMUSTA scheme. The strong agreement between the numerical results compared against some experimental data proves that this method allows a high accuracy and computational efficiency despite the simplicity of the implementation.
Year: 2010