An interface dilation model for the prediction of wall friction in a particulate bed

Abstract

In this paper, the normal and shear stress levels detected by a transducer at the wall of a silo have been compared with predictions derived from the study of single particle wall friction. A simple model is developed which is based on the summation of the estimated individual particle-wall stress contributions over the transducer surface. This analysis is capable of not only predicting the magnitude of the coefficient of wall friction sensed by the transducer but also its variation with position and state of flow. The model includes many single-particle parameters, notable of which are the mean particle size, modulus of elasticity and surface roughness and, in addition, certain fundamental and accessible friction parameters. Furthermore, it contains a less accessible but realistic description of bed dilatancy.