Dynamic Properties of Two-Dimensional PolydisperseGranular Gases

Abstract

We propose a two-dimensional model of polydisperse granularmixtures with a power-law size distribution in the presence of stochasticdriving. A fractal dimension D is introduced as a measurement of theinhomogeneity of the size distribution of particles. We definethe global and partial granular temperatures of the multi-componentmixture. By direct simulation Monte Carlo,we investigate how the inhomogeneity of the size distributioninfluences the dynamic properties of the mixture, focusing on the granulartemperature, dissipated energy, velocity distribution, spatialclusterization, and collision time. We get the following results: a singlegranular temperature does not characterize a multi-component mixture andeach species attains its own ``granular temperature''; The velocitydeviation from Gaussian distribution becomes more and more pronounced andthe partial density of the assembly is more inhomogeneous with theincreasing value of the fractal dimension D; The global granulartemperature decreases and average dissipated energy per particle increasesas the value of D augments.