Rheology of granular mixtures under uniform shear flow: Enskog kinetic   theory versus molecular dynamics simulations
  The rheological properties for dilute and moderately dense granular binary mixtures of smooth, inelastic hard disks/spheres under uniform shear flow in steady state conditions are reported. The results are based on the Enskog kinetic theory, numerically solved by a dense gas extension of the Direct Simulation Monte Carlo method for dilute gases. These results are confronted to the ones also obtained by performing molecular dynamics simulations with very good agreement for the lower densities and higher coefficients of restitution. It appears that the range of densities for which the Enskog equation applies decreases with increasing dissipation. 
J. M. Montanero, V. Garzo, M. Alam, and S. Luding