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 transverse 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 flows consist of a low shear region with higher and more uniform velocities in the lower test section and of a high shear region in the upper parr. The velocities were decreased with the height, and the fluctuations, the granular temperature and the shear rate were increased with the height. The velocity fluctuations were anisotropic and were greater in the streamwise direction. The influences of the lower wall velocity and the mean solid fraction on the flow behavior were investigated in this study. (C) 1998 Elsevier Science Inc. All rights reserved.