Abstract：Coaxial jet flow is widely used in power generation field, but most of the research focus on the dilute granular flow. In order to investigate the flow characteristics of dense gas-solid coaxial jet, dense discrete phase model(DDPM) coupled with discrete element model (DEM) that considers the effect of voidage and inelastic collision between particles, is used in this work. Due to the overwhelming force from gas imposing upon particle, the effects of annular gas velocity and gas-solid drag model are both taken into account. It is shown that the simulation with the DDPM coupled with DEM can lead to reasonable particle dispersion phenomenon. As increasing gas velocity, the particle dispersion appears in the form of shear dispersion mode, wave dispersion mode and oscillation model successively, which is in agreement with experimental observation. And the peak value of time-averaged particle concentration along axis firstly decreases and then increases as enhancing gas velocity, in which there exist two competing mechanisms affecting particle dispersion. Additionally, for high gas velocity, the introduction of turbulence model leads to significant effect that leads to larger particle dispersion. Moreover, different drag models give noticeable difference on the prediction of local particle distribution, in which Wen&Yu model gives the largest particle dispersion, followed by Gidaspow’s model and Syamlal&O’Brien model.
