Inherent rheology of a granular fluid in uniform shear flow
Abstract
In contrast to normal fluids, a granular fluid under shear supports a steady state with uniform temperature and density since the collisional cooling can compensate locally for viscous heating. It is shown that the hydrodynamic description of this steady state is inherently nonNewtonian. As a consequence, the Newtonian shear viscosity cannot be determined from experiments or simulation of uniform shear flow. For a given degree of inelasticity, the complete nonlinear dependence of the shear viscosity on the shear rate requires the analysis of the unsteady hydrodynamic behavior. The relationship to the ChapmanEnskog method to derive hydrodynamics is clarified using an approximate Grad’s solution of the Boltzmann kinetic equation.
 Publication:

Physical Review E
 Pub Date:
 June 2004
 DOI:
 10.1103/PhysRevE.69.061303
 arXiv:
 arXiv:condmat/0309320
 Bibcode:
 2004PhRvE..69f1303S
 Keywords:

 45.70.n;
 05.20.Dd;
 05.60.k;
 51.10.+y;
 Granular systems;
 Kinetic theory;
 Transport processes;
 Kinetic and transport theory of gases;
 Condensed Matter  Statistical Mechanics;
 Condensed Matter  Soft Condensed Matter
 EPrint:
 10 pages, 4 figures