Efficient simulation of liquid–solid flows with high solids fraction in complex geometries

Abstract

An efficient and inexpensive method for the detailed simulation of liquid/solid flows with a high content of large solid particles is presented. In a finite volume context, a fixed Cartesian grid is used to discretize the equations of motion for the liquid phase. The same fixed grid is also used to represent the location of the solid particles by imposing the velocities on the nodes covered by the particles at any time. The new positions and the new velocities of the particles are updated using Newton’s law so that there is no need to re-mesh the domain. Despite the simplicity of the well-known Cartesian Grid Method, the originality and interest of the present approach lies in its use for coupling the liquid and solid phases, and in the efficient way in which the surface forces governing the motion of the particles are computed. The approach is validated using a series of simple test cases, and, as an illustration, an application relevant to the design of tubular heat exchangers for food processing is highlighted.