title: Dynamics of a hard sphere granular impurity.
abstract: An impurity particle coupling to its host fluid via inelastic hard sphere collisions is considered. It is shown that the exact equation for its distribution function can be mapped onto that for an impurity with elastic collisions and an effective mass. The application of this result to the Enskog-Lorentz kinetic equation leads to several conclusions: (1) every solution in the elastic case is equivalent to a class of solutions in the granular case; (2) for an equilibrium host fluid the granular impurity approaches equilibrium at a different temperature, with a dominant diffusive mode at long times; (3) for a granular host fluid in its scaling state, the granular impurity approaches the corresponding scaling solution.
authors.affiliation: Departamento de Física, Universidad de Extremadura, E-06071 Badajoz, Spain. andres@unex.es
authors.forename: Andrés
authors.initials: A
authors.lastname: Santos
authors.forename: James W
authors.initials: JW
authors.lastname: Dufty
mesh_terms: D000465:Algorithms; D004548:Elasticity; D006244:Hardness; D044085:Microfluidics / Q000379:methods*; D016011:Normal Distribution; D010316:Particle Size; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors