title: Thermal segregation of intruders in the Fourier state of a granular gas.
abstract: A low density binary mixture of granular gases is considered within the Boltzmann kinetic theory. One component, the intruders, is taken to be dilute with respect to the other, and thermal segregation of the two species is described for a special solution to the Boltzmann equation. This solution has a macroscopic hydrodynamic representation with a constant temperature gradient and is referred to as the Fourier state. The thermal diffusion factor characterizing conditions for segregation is calculated without the usual restriction to Navier-Stokes hydrodynamics. Integral equations for the coefficients in this hydrodynamic description are calculated approximately within a Sonine polynomial expansion. Molecular dynamics simulations are reported, confirming the existence of this idealized Fourier state. Good agreement is found for the predicted and simulated thermal diffusion coefficient, while only qualitative agreement is found for the temperature ratio.
authors.affiliation: Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, E-41080 Sevilla, Spain.
authors.forename: J Javier
authors.initials: JJ
authors.lastname: Brey
authors.forename: Nagi
authors.initials: N
authors.lastname: Khalil
authors.forename: James W
authors.initials: JW
authors.lastname: Dufty
mesh_terms: D003102:Colloids / Q000737:chemistry* / Q000302:isolation & purification*; D003198:Computer Simulation; D004058:Diffusion; D005583:Fourier Analysis; D005740:Gases / Q000737:chemistry* / Q000302:isolation & purification*; D006358:Hot Temperature; D008956:Models, Chemical; D008958:Models, Molecular; D012212:Rheology / Q000379:methods*
chemical_list: D003102:Colloids; D005740:Gases