Particle velocity distribution function around a single bubble in gas-solid fluidized beds

Particle image velocimetry (PIV) is employed in this work to measure particle flow field in a two-dimensional fluidized bed to obtain particle velocity distribution function around a single bubble. Discrete element method (DEM) is also used to investigate particle velocity distribution at the individual particle scale. Both experimental and simulation results show that the velocity distribution of particles surrounding a single bubble can be described by tri-peak model which is a linear superposition of three Maxwellian distributions. A tri-peak distribution model based on the fluid and particle control mechanisms is theoretically derived. Three kinds of models such as tri-peak model, bi-peak model and single-peak model are proposed and compared. The error analysis shows that compared with other models, the tri-peak model can profile particle velocity distribution more accurately.