EXACT STRESS AND VELOCITY DISTRIBUTIONS IN A COHESIONLESS MATERIAL DISCHARGING FROM A CONICAL HOPPER

The method of characteristics has been used to predict the exact stres s and velocity fields in an incompressible, cohesionless, Coulomb mate rial discharging from a conical hopper for a great variety of boundary conditions imposed on the top surface. It is found that in all cases the stresses and velocity tend to the radial stress and velocity field s and that convergence is achieved about half way down the hopper. Thi s justifies the use of the radial stress field in Jenike's design meth od. The velocity fields often show regions of more or less constant ve locity separated by velocity characteristics. This justifies the assum ptions in Drescher's method of predicting velocity distributions. Copy right (C) 1996 Elsevier Science Ltd