Numerical Simulation of Solid-Liquid Flows Involving Free Surface by DEM-MPS Method

Abstract

In many solid-liquid two phase flow systems, the spatial discretization scale of liquid phase is larger than that of solid phase. This is one of the problems in calculating large-scale solid-liquid flow systems effectively. A new multi -scale Lagrangian model of solid -liquid two phase flows is proposed to simulate the large-scale systems. This model is developed by coupling Discrete Element Method (DEM) with Moving Particle Semi -implicit (MPS) method. This is named as the multi -scale DEM -MPS method. The multi-scale DEM-MPS method makes it possible to treat the spatial discretization scale of the solid and the liquid phase equally by modeling the drag force and the contact force. This is because the drag force acting on the solids and the energy dissipation due to collision depend on the solid size. Two cases of two-dimensional dam-break flow simulation were carried out to investigate the effective- ness of the multi -scale model, where the solid phase volume fraction was 10% and 20% with the original size of 100ƒÊm. The simulations were performed by using the calculated solid whose size was 100 times larger than the original one. The multi -scale Lagrangian model could simulate the original particle behavior from the viewpoints of the suspension by following the fluid streamlines.