A bubbling fluidization model using kinetic theory of granular flow

Detailed knowledge of solids circulation, bubble motion, and frequencies of porosity oscillations is needed for a better understanding of tube erosion in fluidized bed combustors. A predictive two‐phase flow model was derived starting with the Boltzman equation for velocity distribution of particles. The model is a generalization of the Navier‐Stokes equations of the type proposed by R. Jackson, except that the solids viscosities and stresses are computed by simultaneously solving a fluctuating energy equation for the particulate phase. The model predictions agree with time‐averaged and instantaneous porosities measured in two‐dimensional fluidized beds. Observed flow patterns and bubbles were also predicted.