SIMULATION OF MULTIPLE SPHERES FALLING IN A LIQUID-FILLED TUBE

A new 3D finite element how simulation capability for fluid-particle i nteractions is presented and applied to study time-dependent behavior of multiple spheres falling in a liquid-filled tube. This capability i s based on the flow simulation strategies such as stabilized space-tim e formulation for moving boundaries and interfaces, automatic mesh gen eration with structured layers of elements around the spheres, automat ic mesh moving with remesh only as needed, and the implementation of t hese strategies on massively parallel computing platforms. Several cas es of multiple spheres falling in a liquid-filled tube are studied, wi th the number of spheres ranging from two to five. In all cases, depen ding on the number of spheres and their initial arrangement, a stable state is eventually reached with all spheres arranged in a pattern cor responding to that stable state, and with all of them falling with the same terminal velocity.