NUMERICAL ANALYSIS OF HEAT AND MASS TRANSFER ON COLLISION DOMINATED PARTICLES FLOW IN A VESSEL

摘要

Though the solid-gas multiphase flow has been studied experimentally and numerically, the transport phenomena have not been cleared due to its complexity, computational time required and economical costs for hardwares. In this study the heat and mass transfer of solid-gas collision dominated flow in a rectangular vessel is analyzed by the Discrete Particle Simulation (DPS), a kind of the Dispersed Element Methods (DEM)[1]. This method describes the discrete phase and continuous phase by the Lagrange and the Euler methods respectively, and has been used to simulate the multiphase flows of various geometrical systems. In order to analyze the thermal field we took account of the energy equation and heat conduction between colliding particles. We treated the continuous phase as a pseudo two dimensional flow, and the interaction between continuous and discrete phases as two way coupling. The positions, the momenta and the temperature information of particles and velocity and temperature distribution of fluid were obtained as functions of time from results of these numerical simulations. When the hot air flowed from bottom to top in the vessel of packed bed, we traced the particles and got the temperature distribution of fluid. The particles at the surface of the packed bed jumped first and made the void areas at the middle of vessel. We found the void areas that rise in the dispersed particles.