Novel method for measurement of granular temperature distributions in two-dimensional vibro-fluidised beds

A new method for measuring two-dimensional granular temperature distributio ns is presented. This is based on the analysis of the mean squared displace ment behaviour of vibro-fluidised grains at short times, using particle pos ition data from digital high-speed video sequences. The performance of this approach is compared with two others: one based on direct computation of t he mean squared velocity, and the other fitting a Maxwell-Boltzmann distrib ution to the measured velocity distributions in the x and the y directions. The new method proved to be the most consistent, particularly at high pack ing fractions. Typical granular temperature profiles from vibro-fluidised b eds are presented; these indicate that the temperature gradient tends to ze ro at large heights, in contrast to recent Molecular Dynamics (MD) simulati ons presented by Helal et al. [K. Helal, T. Biben, J.P. Hansen, Physics A 2 40 (1997) 361.]. (C) 2000 Elsevier Science B.V. All rights reserved.