Collision Rates in Charged Granular Gases

T. Scheffler; D. E. Wolf

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arXiv · cond-mat/0208288

Collision Rates in Charged Granular Gases

T. Scheffler·D. E. Wolf

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Abstract

The dissipation rate due to inelastic collisions between equally charged, insulating particles in a granular gas is calculated. It is equal to the known dissipation rate for uncharged granular media multiplied by a Boltzmann-like factor, that originates from Coulomb repulsion. Particle correlations lead to an effective potential that replaces the bare Coulomb potential in the Boltzmann factor. Collisional cooling in a granular gas proceeds with the known t^-2 -law, until the kinetic energy of the grains becomes smaller than the Coulomb barrier. Then the granular temperature approaches a time dependence proportional to 1/ln(t). If the particles have different charges of equal sign, the collision rate can always be lowered by redistributing the charge, until all particles carry the same charge. Finally granular flow through a vertical pipe is briefly discussed. All results are confirmed by computer simulations.

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T. Scheffler, D. E. Wolf. 2002-08-14. Collision Rates in Charged Granular Gases. https://arxiv.org/abs/cond-mat/0208288

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