Physics
Collision statistics of driven granular materials
Document Type
Article
Abstract
We present an experimental investigation of the statistical properties of spherical granular particles on an inclined plane that are excited by an oscillating side wall. The data is obtained by high-speed imaging and particle tracking techniques. We identify all particles in the system and link their positions to form trajectories over long times. Thus, we identify particle collisions to measure the effective coefficient of restitution and find a broad distribution of values for the same impact angles. We find that the energy inelasticity can take on values greater than one, which implies that the rotational degrees of freedom play an important role in energy transfer. We also measure the distance and the time between collision events in order to directly determine the distribution of path lengths and the free times. These distributions are shown to deviate from expected theoretical forms for elastic spheres, demonstrating the inherent clustering in this system. We describe the data with a two-parameter fitting function and use it to calculate the mean free path and collision time. We find that the ratio of these values is consistent with the average velocity. The velocity distributions are observed to be strongly non-Gaussian and do not demonstrate any apparent universal behavior. We report the scaling of the second moment, which corresponds to the granular temperature, and higher order moments as a function of distance from the driving wall. Additionally, we measure long-time correlation functions in both space and in the velocities to probe diffusion in a dissipative gas. © 2003 The American Physical Society.
Publication Title
Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
Publication Date
1-2003
Volume
67
Issue
4
First Page
12
ISSN
1063-651X
DOI
10.1103/PhysRevE.67.041301
Repository Citation
Blair, Daniel L. and Kudrolli, A., "Collision statistics of driven granular materials" (2003). Physics. 134.
https://commons.clarku.edu/faculty_physics/134
Cross Post Location
Student Publications
