Kinetic Theory and Memory Effects of Homogeneous Inelastic Granular Gases under Nonlinear Drag

Area of Science:

• Physics
• Statistical Mechanics
• Granular Materials

Background:

• Granular gases interact with thermal baths, exhibiting complex dynamics.
• Understanding energy dissipation and steady states is crucial.

Purpose of the Study:

• To develop and validate kinetic theory for granular gases in a thermal bath.
• To accurately predict granular temperature, aging, and memory effects.

Main Methods:

• Utilized an Enskog-Fokker-Planck equation for kinetic theory.
• Applied Maxwellian and first Sonine approximations for analytical solutions.
• Validated predictions using Direct Simulation Monte Carlo and event-driven molecular dynamics.

Main Results:

• The first Sonine approximation significantly improves agreement with simulations, especially with increased inelasticity and drag.
• Maxwellian approximation provides good results for granular temperature.
• The first Sonine approximation is essential for capturing memory effects like Mpemba and Kovacs.

Conclusions:

• The first Sonine approximation offers a more accurate description of granular gas dynamics in thermal baths.
• This approach is vital for understanding complex phenomena like Mpemba and Kovacs effects in granular systems.