Numerical Simulation of the Fluid-Solid Two-Phase in the Horizontal Pipe Based on DEM-CFD Coupling Method

Compared to the conventional CFD method, the CFD–DEM coupling is proposed to simulate the solid–liquid two–phase flow in the horizontal pipe in this paper. The standard k–ε model was utilized for fluid turbulent flow, the standard wall functions for near-wall zone treatment, and the Hertz–Mindlin (no slip) model for particle–particle and particle–wall contact. The movements and distribution of particles in different inlet velocities and pressure drop in pipeline are investigated in this paper. The results show that the coarse particles appear starting, discontinuous movement as bedload, continuous movement as bedload, and suspension in order with mean velocity of fluid media increase; with the increasing inlet velocity, the distribution of partilces in the pipe becomes more even, however, the concentration of the particles on the botton is larger than that on the top. Moreover, the pressure drop predicted by this method is compared with the Churchill pressure drop model and results are not identical. Therefore, the regular of pressure drop is demonstrated in this paper.