Dense fluid transport for inelastic hard spheres.

Area of Science:

• Physics
• Granular Materials Science
• Statistical Mechanics

Background:

• The revised Enskog theory provides a framework for understanding granular media.
• Finite density effects are crucial in granular flow dynamics.

Purpose of the Study:

• To model rapid flow granular media at finite densities using inelastic hard spheres.
• To identify Navier-Stokes order transport coefficients and cooling rates.

Main Methods:

• Chapman-Enskog method for normal solutions near the local homogeneous cooling state.
• Analysis to first order in spatial gradients.
• Sonine polynomial expansion for calculating transport coefficients.

Main Results:

• Identification of transport coefficients for heat and momentum fluxes.
• Calculation of the cooling rate to first order in gradients.
• Explicit functions for transport coefficients derived in terms of density and restitution coefficient.

Conclusions:

• The revised Enskog theory effectively models granular flow.
• Results show excellent agreement with a simpler kinetic model, validating the approach.