Granular temperature profiles in three-dimensional vibrofluidized granularbeds - art. no. 061311

The motion of grains in a three-dimensional vibrofluidized granular bed has been measured using the technique of positron emission particle tracking, to provide three-dimensional packing fraction and granular temperature dist ributions. The mean square fluctuation velocity about the mean was calculat ed through analysis of the short time mean squared displacement behavior, a llowing measurement of the granular temperature at packing fractions of up to eta similar to 0.15. The scaling relationship between the granular tempe rature, the number of layers of grains, and the base velocity was determine d. Deviations between the observed scaling exponents and those predicted by recent theories are attributed to the influence of dissipative grain-sidew all collisions.