Modeling free-surface flows of granular column collapses using a mesh-free method

The dry granular mass in the dense flow regime can be considered as continuum and incompressible and is modeled in this study by using a mesh-free method, moving particle semi-implicit method (MPS). A local rheology model is employed to calculate the effective viscosity and shear stress in granular flows in the numerical method. Flows of cylindrical column collapse on planes and rectangular dam-break in channels containing glass beads and sands were respectively simulated in two-dimensional. From modeling a series of granular flows, the rheology model in MPS reproduced the flow characteristics of granular materials including flowing surface and the distinct static internal part where low velocity exists. The simulations prove that the initial column ratio played an important role in the spreading of granular mass. The surface profiles and wave front movements were compared with experimental data from literatures. After a transient period in the initial flow, the wave front of the granular flow approximately travels in a constant speed which was similar to that observed in the experiments. The final wave front in the simulations also showed good agreement with the relationship obtained from experiments. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.