Measurement of particle motions within tumbling granular flows

Flowing granular materials are complex, industrially important, and scienti fically provocative. In this paper we report measurements of granular trans port in 3-dimensional tumbling containers. We use magnetic resonance imagin g techniques for direct tracking of particles and measure the interior flow s of granular materials. One goal is to measure industrial mixer performanc e over a wide range of conditions. As the mixer geometries are relatively s imple, such measurements could serve as incisive tests during development o f better granular equations of motion. (C) 1999 American Institute of Physi cs. [S1054-1500(99)02903-1].