The project deals with a combination of simple experiments and numerical simulations to compute hydrodynamic forces on particles in dispersed two-phase flow. The experiments are on the following five topics: (1) Evaluation of the inertial effects in oil-water mixtures, (2) The effective density of mixtures of fluids and solids, (3) Determination of the frequency of wake interactions of fluidized spheres, (4) Image analysis of two-dimensional beds of particles, and (5) Lubricated transport of flowing particulates. Corresponding two-and three-dimensional finite element simulations will be performed for flows satisfying the Navier-Stokes equations. Forces and couples acting on particles will be determined. The objective of the research program is to obtain data for a "molecular dynamic" simulation of flowing mixtures. This project will develop fundamental information necessary for modeling of interaction forces and flow characteristics in particulate two-phase systems, with application to a variety of processes in industry and natural phenomena.