An analysis of turbulent gas-particle flow has been conducted for which dilute and dense flows were considered. This study showed that, although, there are a variety of models postulated for the analysis of dilute-phase particulate transport, there exists limited information on dense-phase flow. Several derivations of multi-phase flow equations have appeared in the literature. The differences between these equations are in the momentum source terms, the pressure gradient terms and in the convection terms of the dispersed phase momentum equation. In most of the studies on dilute two-phase flow, the effects of the dispersed phase on fluid turbulence have not been considered at all or considered only in an ad hoc fashion. In the few studies where such effects have been incorporated properly, many simplifying assumptions and various empirical constants were introduced. Evaluation of the constants was made via a comparison between model predictions and experimental data. Among these studies the work of Elghobashi and his co-workers, in general, and of Rizk (1985), in particular, provides a foundation for the extension to densely loaded gas/solid flows. Based on this approach, a new mathematical model has been formulated to analyze densely loaded gas/solid flows taking into account particle-particle interactions and gas-particle interactions. 136 refs., 2 figs., 2 tabs.