Investigating the physical characteristics of dense granular flows by coupling the weakly compressible moving particle semi-implicit method with the rheological model

Abstract

Mesh-free methods have recently been coupled with constitutive rheological models to model dynamics in dry granular flows. However, this approach has not yet been comprehensively validated in different configurations with regard to the pressure, velocity, shear stress, free surface, and friction factor. Therefore, this study applied the weakly compressible moving particle semi-implicit method (WC-MPS) coupled with the μ(I) rheology model to investigate three different cases: flow on an inclined plate, 2D column collapse, and granular dam-break flow. In the simulations, the flow characteristics were successfully captured in each of the different flow scenarios. In the granular flow on an inclined plate, the coupled model reproduced a steady uniform zone, in good agreement with analytical solutions in terms of pressure, shear stress, friction factor, and velocity distribution. In the 2D column collapse and granular dam-break flow, the coupled model showed good performance in capturing dynamic features from experimental observations. The numerical results of the coupled model for the pressure, shear stress, and friction factor were analysed, and the coupled model was found to distinguish flow regimes in the granular flows according to the calculated pressure, stress, and friction factor. The numerical results showed nonlinear distributions with dramatic changes in the pressure and shear stress on the free surface. Thus, this study demonstrated that the WC-MPS method coupled with the μ(I) rheology model can reflect granular flow characteristics.