Periodic boundary conditions of discrete element method-lattice Boltzmann method for fluid-particle coupling

This paper presents a periodic boundary condition for the coupled discrete element and lattice Boltzmann method for simulating fluid-particle systems. Detailed implementation of this special boundary condition is given. Besides, the detailed procedure of immersed moving boundary scheme for fluid–solid coupling is proposed. The accuracy and applicability of the proposed periodic boundary condition are well demonstrated by two benchmark tests, i.e. single particle transport and multiple particle migration in an infinite tube filled with water. It is found that the novel periodic boundary condition proposed for discrete element and lattice Boltzmann method can greatly improve the computational efficiency of the later which is computationally expensive when thousands of particles are involved.