On modeling rapid granular flows

In this paper the recent developments concerning modeling of rapid flows of granular material is presented. Particular emphasis is given to thermodynamically-based continuum models. It is shown that these models include a transport equation for the particulate fluctuation energy, and in more advanced version, for evolution of components of the kinetic stress tensor. The implication of generalized (extended) thermodynamical principles in modeling particulate pouts in a state of rapid motion are described. The special cases of rapid simple shear flows of granular materials is discussed. Comparisons of the model predictions for granular stresses and normal stress differences with the available simulation results are presented. The effects of inter-granular friction, and interstitial fluids on flouts of particulate media is also discussed.