Approximate solutions to the problem of stationary shear flow of smooth granular materials

The inelastic Boltzmann equation is used in order to study stationary shear flows in a rarefied granular gas of hard spheres. We resort to a Gaussian moment approximation in order to calculate the pressure tensor in three dimensions. The method is discussed along with previously introduced techniques: asymptotic expansion in the near elastic limit, and pseudo-Maxwellian approximation. Numerical results and approximate analytic formulas for the pressure tensor are presented and briefly commented on. A comparison with the pseudo-Maxwellian solution is discussed in detail.