Aging to non-Newtonian hydrodynamics in a granular gas

TL;DR

This paper demonstrates through simulations that a granular gas under shear flow quickly reaches a non-Newtonian hydrodynamic state, even with strong dissipation, and confirms the model's accuracy in describing this behavior.

Contribution

It shows that granular gases evolve to a non-Newtonian hydrodynamic regime regardless of initial conditions, supported by simulation data and rheological model comparison.

Findings

Rapid transition to non-Newtonian hydrodynamics

Agreement between simulations and rheological model

Persistence of non-Newtonian behavior at strong dissipation

Abstract

The evolution to the steady state of a granular gas subject to simple shear flow is analyzed by means of computer simulations. It is found that, regardless of its initial preparation, the system reaches (after a transient period lasting a few collisions per particle) a non-Newtonian (unsteady) hydrodynamic regime, even at strong dissipation and for states where the time scale associated with inelastic cooling is shorter than the one associated with the irreversible fluxes. Comparison with a simplified rheological model shows a good agreement.