Comparison of the mu(I) and HBP models for simulating granular media

摘要

Application of Lagrangian meshless methods in modeling granular flow has been a major concern for researchers due to their particular nature. For modeling granular movement, it is assumed that the particles are continuous. The SPHysics code is developed for modeling the movement of Newtonian fluids in which the pressure is derived from the state equation. In this study, mu(I) and Herschel-Bulkley-Papanastasiou (HBP) viscoplastic models are implemented in the SPHysics code to analyze the movement of grains induced by the applied stresses. In the first model, the movement of granular particles is based on the characteristics such as inertia and friction coefficient, and in the second model, the movement is related to the non-Newtonian viscoplastic behavior of fluids. The accuracy of the models is evaluated by simulating the experimental benchmarks for granular dam break. The effect of length-to-height ratio on the failure mode of dam break phenomenon is also investigated. The performance of the models is increased by introducing the gate removal speed and also the harmonic mean of the viscosity instead of the viscosity proper to each particle. This study shows that the models could capture the behavior of grains in the static and the dynamic parts of the mass body.