Abstract: A second-order moment model of particles is proposed inthe dense gas-solid flow based on the kinetic theory of granular flow andkinetic theory of gases. The constitutive model of solid phase is closedwith the approximated third-order moment enclosure equation of particlevelocity from the elementary transport theory. The boundary conditions ofvelocity and fluctuating velocity energy of particles are proposed with theconsideration of the energy transfer and dissipations by collisions betweenthe wall and particles. Interaction between gas phase and solid phase ismodeled by Koch (1999) mode. Flow behavior of particles is simulated in ariser. Numerical simulations indicate the distinct anisotropy behavior ofthe turbulent particles in the riser. Simulated particle velocities,concentration and second-order moments are in agreement with measurements byTartan and Gidaspow (2004) in a riser. Predicted axial fluctuating energy ofparticles is on average 1.5 times the mean fluctuating energy of particles,and the axial fluctuating energy is 3.0 times the lateral fluctuating energyof particles.