Diffusion and Velocity Auto-Correlation in Shearing Granular Media

الأصل · EN

We perform numerical simulations to examine particle diffusion at steady shear in a model granular material in two dimensions at the jamming density and zero temperature. We confirm findings by others that the diffusion constant depends on shear rate as D γqᵈ with qD<1, and set out to determine a relation between qD and other exponents that characterize the jamming transition. We then examine the the velocity auto-correlation function, note that it is governed by two processes with different time scales, and identify a new fundamental exponent, λ, that characterizes an algebraic decay of correlations with time.