SELF-CONSISTENT EFFECTIVE BINARY INTERACTION APPROXIMATION FOR STRONGLY COUPLED MULTIFLUID DYNAMICS

An improved self-consistent effective binary diffusion approximation f or multicomponent diffusion was recently described [1]. Here we develo p an analogous self-consistent effective binary interaction (SCEBI) ap proximation for simplifying multifluid dynamical descriptions in which each fluid is strongly coupled to the other fluids by pairwise fricti onal forces. The net drag force on each fluid is the summation of the drag forces due to each of the other fluids. This summation is approxi mated by a single term proportional to the velocity of the fluid in qu estion relative to an appropriately weighted average velocity. This ap proximation permits an explicit numerical solution for the fluid veloc ities even when the drag terms are evaluated at the advanced time leve l to avoid explicit stability restrictions on the time step.