MEASUREMENTS OF VELOCITY FLUCTUATIONS OF GRANULAR-MATERIALS IN A SHEAR CELL

This paper studies the flow behavior of granular materials in a shear cell. The average and fluctuating velocities in the streamwise and tra nsverse directions were measured by the image processing technique and particle tracking method. The granular materials were put in a shear cell to simulate the Couette flow with a stationary upper wall. The fl ows consist of a low shear region with higher and more uniform velocit ies in the lower test section and of a high shear region in the upper parr. The velocities were decreased with the height, and the fluctuati ons, the granular temperature and the shear rate were increased with t he height. The velocity fluctuations were anisotropic and were greater in the streamwise direction. The influences of the lower wall velocit y and the mean solid fraction on the flow behavior were investigated i n this study. (C) 1998 Elsevier Science Inc. All rights reserved.