Numerical Simulation And Experimental Study Of Free Falling Particle Plume

In the nature and practical engineering applications, the gas-solid two phase free falling particles plume flows are typical. Studies on them are helpful to understand the turbulence mechanism and the interaction mechanism between the gas and the solid particles, and also are directive to the associated engineering applications, and can provide references to the theory-developing and experiment-investigating of the more complicated gas-solid two-phase flows. So, it is not only of academic theoretical significance but also has the extensive engineering application value to carry out the study on the gas-solid two-phase free falling particles plume flows. Under these back grounds, this dissertation focuses on the study of the numerical simulation and experiment study of the gas-solid two-phase free falling particles plume flows, including the use of the CFD software FLUENT 6.2 and the experimental study of the two-dimensional gas-solid two-phase free-falling particle plume. The main objective is to investigate the evolution of the particle diameter, the drop height, the particle density, particle mass flow rates and the distributing of the temperature by the effects of the particles on the air entrainment and particle velocity distribution of the particle plume.In the numerical simulation of the free-falling particle plume flow, the flow is assumed to be temporally evolving and incompressible. The particles are initially discharged from the upper region. The governing equations of the gas-phase are solved by using the Realizable k -εModel. And the particle trajectories are traced by using the discrete phase model. The influence on the dispersion characteristics and dispersion mechanism of the particle plume flow with different particle parameter is well studied.In the process of experimental study, a series of experiments are performed to demonstrate the measurement methodology for air entrainment by free falling particles. These experiments are carried out to investigate the effects of material properties and material process parameters, such as mass flow rate of bulk material, particle size distribution, particle density, outlet size of the discharging hopper and particle drop height. The comparison of the results of the present study on the air entrainment in the particle plume indicated the validity the theoretical particle plume model.