NUMERICAL-SIMULATION OF A 2-PHASE GAS-PARTICLE JET IN A CROSS-FLOW .2. FREE STREAM-VELOCITY GRADIENT AND HEAT-TRANSFER MECHANISM

Abstract

A computational model using Lagrangian approach has been proposed to analyze momentum and heat transfers of a gas-particle jet in a crossflow. The effect of the free stream velocity gradient on the two-phase crossjet trajectories and the heat transfer mechanism was investigated in this study. Estimate of average temperature of a particle-laden gas jet was obtained by accounting for thermal energy losses of the gas jet flow due to forced convection and to entrainment of free stream fluid into the jet and for thermal energy transferred from the particles to the gas jet. According to the computational results of the heated two-phase temperature of a gas-particle jet in a crossflow. crossjet, the mean temperature of the carrier gas phase near the jet exit is dependent upon the forced convection and entrainment of the free stream, while far downstream, it is mainly affected by the quantity of thermal energy transferred from the solid particles to the carrier gas phase. When the ratio of the gas jet momentum flux to the momentum flux of the cross free-stream at the jet exit and the free stream conditions are constant, the trajectories of the particle-laden gas and particle phases and the normalized mean temperature difference between both phases are not significantly affected by the change of injection gas