Abstract：The computational fluid dynamics method (CFD) based on continuum model and the discrete element method (DEM) were coupled together to establish a CFD-DEM method which was used to simulate the coarse particle fluidization process in this study. The method of statistical analysis was applied to study the particle velocity distribution function, and the Maxwellian distribution, exponential distribution, bimodal distribution and t-distribution were used to regress the simulated data to explore the reasonable velocity distribution characteristics in the non-uniform gas-solid two-phase flow. It is shown that Maxwell distribution cannot be used to describe the particle velocity distribution in the non-equilibrium gas-solid flow; t distribution or exponential distribution can fit the velocity distribution in the non-gravitational direction well; while bimodal distribution offers a best fitting with the simulation data in the gravitational direction.

Keywords：gas-solid flow; particle velocity distribution; kinetic theory; fluidization