A three-dimensional turbulent gas-solid two-phase flow model for a gas-solid injector is developed in the present study. Time-averaged conservation equation for mass and momentum and a two-equation k-epsilon closure are used to model the carried fluid phase. The solid phase is simulated by using a Lagrangian approach. In this model, the drag and lift forces on particles, the multi-body collisions among particles and the mutual interaction between gas and particles were taken into account. Interparticle interactions and particle-wall collisions are emulated by using the three-dimensional distinct element method (DEM). A new correlation, beta((delta vp delta vp) over bar -(delta u delta vp) over bar) = -2 beta K(1-tau(L)/(tau(L)+tau(d)))tau(L)/(tau(L)+tau(d)), which represents the transfer of kinetic energy of the particle motion to kinetic energy of the carrier fluid, is introduced in the additional source term Sd epsilon of the transport equation of turbulence kinetic energy, K. The calculated pressure distributions along the axis in the different parts of gas-solid injectors using pressured pneumatic conveying system under different driving jet velocities, pressures and values of angle of convergent section (a) are found to be in agreement with the experimental results. The axial mean velocity of particles and the behavior of gas and particles in the gas-solid injector are calculated, their results reasonably explaining actual phenomenon observed in experiment. (c) 2005 Elsevier B.V All rights reserved.