Multiscale modelling and analysis of particle-fluid flows in packed and fluidized beds

This work studied the particle-fluid flows in packed and fluidized beds by multiscale simulations. The focus was on the relationship between microscopic particle-particle/particle-fluid interactions and macroscopic behaviors of the systems. Particle scale simulations using the coupled computational fluid dynamics and discrete element method (CFD-DEM) were conducted for understanding the settling, defluidization and gas-fluidization of particles. The discrete particle simulation was also linked to continuum properties through averaging method of granular materials. Pore scale network model was developed for simulating fluid flows through packed beds; its coupling with DEM was also realized for simulation of particle-fluid flows at an equivalent scale.