DSMC evaluation of the Navier–Stokes shear viscosity of a granular fluid

A method based on the simple shear flow modified by the introduction of a deterministic non-conservative force and a stochastic process is proposed to measure the Navier–Stokes shear viscosity in a granular fluid described by the Enskog equation. The method is implemented in DSMC simulations for a wide range of values of dissipation and density. It is observed that, after a certain transient period, the system reaches a hydrodynamic stage which tends to the Navier–Stokes regime for long times. The results are compared with theoretical predictions obtained from the Chapman–Enskog method in the leading Sonine approximation, showing quite a good agreement, even for strong dissipation.