Granular Material Flow in Two-Dimensional Hoppers

Abstract

The flow and transport of granular media have been of major importance in commerce and industry for a long time; materials such as coal, ore, cement, grain, soap granules, sugar, sand, gravel, etc., flow in hoppers, bins, chutes, rotating drums, and moving bands. The desire to improve such transportation equipment and to reduce the energy expenditure has motivated interest in understanding the fluid mechanics of such bulk flows (Wieghardt [25]1). Though transport, heat transfer, and other processes are often effected by fluidization we are concerned here with those situations in which the flow takes place with direct physical contact between the grains. Indeed the simplest situation is that in which the interstitial fluid (usually air) has a negligible effect on the equations of motion. The purpose of this paper is to present a comparison of experimental data and analysis for the flow of dry granular media through a two-dimensional or wedge-shaped hopper. It will be seen that the analytical solution which begins with the constitutive postulates suggested by Jenike and Shield [9] of (i) intergrain Coulomb friction and (ii) isotropy produces results which are in good agreement with the experimental measurements.