Entrainment effect of dry and saturated path material on granular flow movement and the force of granular flow impacting on the retaining wall: A numerical study

Abstract

In this study, the effects of granular flow on dry and saturated entraining materials along the flow path and the force of granular flow impacting on the retaining wall are numerically investigated. Numerical simulations of the existing granular flow entrainment experiment are conducted to evaluate the accuracy and effectiveness of the adopted discrete element method (DEM). Subsequently, the movement and entrainment process of the granular flow aimed at investigating the entrainment effect and the normal force acting on the retaining wall, is studied. Velocity of the granular flow decreases a lot due to entrainment. As a result, many particles are accumulated along the flume bottom and the peak/residual normal force acting on the rigid wall decrease significantly. Finally, DEM and computational fluid dynamics (CFD) are coupled to simulate the granular flow entrainment with a saturated path material. The result shows that after adding fluid to the entrainment area, the entrainment area has a more significant deceleration effect on the quickly passing source particles due to fluid resistance. Furthermore, the interaction between the fluid and the original particles in the entrainment area makes the particles in the entrainment area being less susceptible to be entrained by the granular flow.