A two-phase morphodynamic model has been developed to simulate dam-break wave on a mobile bed. The numerical implementation of such a model using classical upwind methods remains a challenging task due to the complexity of developing a suitable Riemann solver for multi-phase flow problems. The present study employs the GMUSTA method to compute the numerical intercell fluxes, which is simpler and avoids the solution of the Riemann Problem in the conventional sense. GMUSTA is a multi-stage centered-scheme for constructing numerical intercell fluxes using a local grid around the interface. It is capable of reproducing the high accuracy of upwind schemes while keeping the simplicity of centered schemes. Several laboratory experiments of dam-break wave over a mobile bed from the literature were simulated using a one-stage GMUSTA implementation. The numerical results obtained with the GMUSTA method were compared against those obtained using a second-order accurate classic finitevolume implementation of the same mathematical model and the measured experimental data. It is shown that the numerical results obtained through a 1-stage GMUSTA implementation give a good agreement with the experimental results. A significant improvement is achieved with respect to the classic upwind method in terms of simplicity and computational efficiency.
GMUSTA Method for Numerical Solution of Dam Break Flow on Mobile Bed.
EVANGELISTA, Stefania;LEOPARDI, Angelo
2010-01-01
Abstract
A two-phase morphodynamic model has been developed to simulate dam-break wave on a mobile bed. The numerical implementation of such a model using classical upwind methods remains a challenging task due to the complexity of developing a suitable Riemann solver for multi-phase flow problems. The present study employs the GMUSTA method to compute the numerical intercell fluxes, which is simpler and avoids the solution of the Riemann Problem in the conventional sense. GMUSTA is a multi-stage centered-scheme for constructing numerical intercell fluxes using a local grid around the interface. It is capable of reproducing the high accuracy of upwind schemes while keeping the simplicity of centered schemes. Several laboratory experiments of dam-break wave over a mobile bed from the literature were simulated using a one-stage GMUSTA implementation. The numerical results obtained with the GMUSTA method were compared against those obtained using a second-order accurate classic finitevolume implementation of the same mathematical model and the measured experimental data. It is shown that the numerical results obtained through a 1-stage GMUSTA implementation give a good agreement with the experimental results. A significant improvement is achieved with respect to the classic upwind method in terms of simplicity and computational efficiency.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
