A computational study is carried out for a dilute turbulent liquid-particle flow impinging a centerbody through a sudden-expansion pipe. An improved Lagrangian stochastic particle-dispersion model and a second-moment Reynolds-stress transport model are used for the dispersed and continuous phases, respectively. Complete initial conditions obtained from the experimental measurements are used to specify the two-phase flow conditions at the inlet. Detailed experimental measurements of both the liquid- and particle-phases at several downstream stations are employed to validate numerical predictions by comparing the predicted and measured radial profiles of such two-phase flow properties as mean and fluctuating velocities, mass fluxes, and mean diameters. In addition, the problem of correcting artificial accumulation is also addressed. It is found that numerical predictions obtained with the improved particle-dispersion model are in reasonable agreement with experimental measurements.