Numerical Studied On Coupled Sediment Particles Motion And Hydrodynamic Flows With Free Surface

Sediment transportation problem has always been an important content in river dynamic research. As the sediment motion has a significant effect on the changes of river, research with the mesoscopic view on sediment motion behavior under free surface flows is of great significance. The studies on sediment particles' motion with the mesoscopic view cancontribute to the discussion about several mechanism of sediment dynamics, and to develop the model of macroscopic calculation which is benefit to the engineering application.In order to investigate the sediment transportation by means of numerical simulating particles' motion, a numerical model coupling of CFD and DEM has been established in the present paper. The codes in-house is based on Fortran, and is paralleled by OpenMP language library. There are two types of particle collision modes established in the present numerical model system, i.e. the rigid particle mode and the soft particle mode.To verify the numerical model, three study cases were carried out. The first one is about the free falling motion of a single spherical particle in the still water, the second one is about the motion of well mixed particles with different density initially in the still water, and the last one is about the effect of standing waves on the bed sediment motions. With the primary validations, the present numerical model is confirmed to be feasible in the research of sediment dynamics with the mesoscopic view.