(189v) Simulation of a Confined Turbulent Two Phase Jet Flow

This paper deals with 3D mathematical modelling of a confined turbulent two-phase jet flow. The model treats the gas and the solid phases from an Eulerian approach. The closure of the averaged time transport equations have been accomplished by using a k-ε turbulence model. The accuracy of the model predictions in a particle-laden confined jet with time averaged characteristics as well as turbulence correlation coefficients have been improved. Radial mean velocity profiles for the particulate phase were computed on eight axial levels, subdivided in two cases of four profiles. The results were compared with experimental data obtained with Phase Doppler Anemometry on a plexiglass chamber with three nozzle entrances in the top, two of them for the gas flow and the other one for a mixture between gas and particles. This last one was located in the central position. The mean particle diameter used for the two phase mixture was 75µm. The inlet velocities used in the central nozzle were 4 and 4.5m/s. The gas superficial velocities in the two adjacent nozzles were different for each case. The interparticle collisions occur frequently in the local regions with higher particle concentration of the flow field. Under the influence of the local accumulation and the turbulent transport effects, the variation of the average interparticle collision number with the Stokes number allows a complex non-linear relationship. The particle distribution is more uniform as a result of interparticle collisions, and the lateral and the spanwise dispersion of the particles considering interparticle collision also increase. The model predicts a flow development similar to that found experimentally.