(146f) A Numerical Algorithm for Simulating Dense Polydisperse Gas--Particle Flows Using a Mass--Velocity Quadrature-Based Moment Method

Kong, B. - Presenter, Iowa State University
Fox, R., Iowa State University
Polydisperse gas-particle flows are common in many fields of engineering, such as in fluidized beds and risers, which are widely used in a variety of chemical processes. Due to the various physical and chemical interactions between particles and gas, such as particle collisions and breakage, gasification and chemical reactions, the individual particle size and the overall size distribution of particles changes as the flow develops. In this work, quadrature-based moment methods (QBMM) are applied to solve numerically the kinetic equation of the joint NDF with the hydrodynamic approximation for particle velocity, which is valid when particles are in the moderately dense and dense regime, such as in fluidized bed. By reconstructing the size-conditioned velocity distribution function, the spatial fluxes in the moment equations are treated using a kinetic-based finite-volume method. This approach was implemented in an open-source CFD package and then tested in a fluidized bed case. The results demonstrate that the ability of the code to capture the size segregation and size change due to aggregation and breakup, and that our approach is an effective way to model complicated polydisperse gas-particle flows.