Thermal segregation of intruders in the Fourier state of a granular gas

TL;DR

This paper investigates thermal segregation of intruder particles in a granular gas using an exact Boltzmann solution called the Fourier state, combining kinetic theory and molecular dynamics simulations to analyze segregation conditions.

Contribution

It provides an exact analytical solution for thermal segregation in granular gases beyond Navier-Stokes hydrodynamics, supported by molecular dynamics simulations.

Findings

Calculated thermal diffusion factor for segregation conditions.

Validated theoretical results with molecular dynamics simulations.

Extended understanding of granular gas behavior beyond traditional hydrodynamics.

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 exact 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. Molecular dynamics simulations are reported for comparison with the results for this idealized Fourier state.