Extension of a model for the distribution of voidage around bubbles in a fluidized bed

Up to date most models predicting the voidage around bubbles in fluidized beds assume a simple two-phase flow model. A classic example of a model using this basic assumption is the Davidson and Harrison bubble model. In more recent experimental studies it has been shown that there exists a shell of lower voidage around a bubble in a fluidized bed. Better understanding of these phenomena might play a significant role in understanding other very important effects associated with bubbles in fluidized beds. An example of this might be better understanding the wake of a bubble rising in a fluidized bed and also to better predict mixing in a fluidized bed. The amount of contact between the gas and the solids in a gas-solid fluidized bed is paramount for designing an effective fluidized bed reactor.