HYDRODYNAMICS FOR GRANULAR FLOW AT LOW-DENSITY

The hydrodynamic equations for a gas of hard spheres with dissipative dynamics are derived from the Boltzmann equation. The heat and momentu m fluxes are calculated to Navier-Stokes order and the transport coeff icients are determined as explicit functions of the coefficient of res titution. The dispersion relations for the corresponding linearized eq uations are obtained and the stability of this linear description is d iscussed. This requires consideration of the linear Burnett contributi ons to the energy balance equation from the energy sink term. Finally, it is shown how these results can be imbedded in simpler kinetic mode l equations with the potential for analysis of more complex states. [S 1063-651X(98)15709-4].