Simple Mean Free Path Theory for Stresses in a Rapid Granular Flow

Abstract

Kinetic stress for a rapidly deforming granular material is first derived. The derivation uses a simple velocity distribution model together with a mean free path concept. Complete stresses including the collisional stresses are obtained using this method. The results compare favorably with those obtained from other theories and experimental data. This model provides an alternative to the more elaborate perturbation techniques used in determining the velocity distribution function. The close agreement between the results obtained from the present model and theories which use more elaborate velocity distributions suggests that details of the velocity distribution are not as important as the correct averaging method for the computation of stresses in a rapidly deforming granular material.