Performance evaluation of rheological models and yield criteria in simulating rapid flow-induced sediment erosion using SPH

Abstract

In reality, flash flooding induced by dam failure contains a considerable amount of sediments, which can cause significant loss of lives and properties in the downstream area. A numerical model using weakly compressible smoothed particle hydrodynamics (WCSPH) is developed to simulate sediment transport induced by rapid flows. As a key approach to track sediment transport, rheological models (Bingham-type, Bingham, Herschel-Bulkley-Papanastasiou) in conjunction with different yield criteria (Mohr-Coulomb and Drucker-Prager) are implemented, and their performances are rigorously evaluated through reproducing three experiments of dam-break flow over movable bed. Numerical results from three cases reveal that HBP-MC combination is more stable and performs the best in simulating sediment erosion and free-surface induced by rapid flows. Whilst the DP yield criterion appears to over-predict sediment erosion for both PVC and sand bed experiments. The velocity is almost zero in the un-eroded sediment layer and increases in a logarithm manner in the eroded sediment layer while in an exponential manner in the fluid layer. The results obtained from the SPH simulation can reasonably explain the sediment-liquid interaction mechanisms, erosion and evolution at both microscopic and mesoscopic scales.