FLUIDIZATION OF A 2-DIMENSIONAL GRANULAR SYSTEM - EXPERIMENTAL-STUDY AND SCALING BEHAVIOR

Digital high speed photography and computer image processing have been used to investigate the fluidization behavior of a two-dimensional mo del granular material undergoing vertical vibration. Profiles of packi ng fraction, speed, and velocity distribution functions are measured. The packing fraction is found to be approximately uniform in a narrow region at the base, and a Boltzmann distribution gives a good fit in t he upper regions. Values for the granular temperature, as a function o f height, are extracted from the distribution functions and an approxi mately linear decay is found. We also present results for the scaling behavior of the granular temperature and the height of the center of m ass. Finally, we describe a simple theoretical analysis to investigate the origin of scaling laws.