Instability of symmetric Couette flow in a granular gas: Hydrodynamic field profiles and transport

We investigated the inelastic hard-disk gas sheared by two parallel bumpy w alls (Couette flow). In our molecular dynamic simulations we found a sensit ivity to the asymmetries of the initial particle positions and velocities a nd an asymmetric stationary state, where the deviation from (anti)symmetric hydrodynamic fields is stronger as the normal restitution coefficient decr eases. For better understanding of this sensitivity we carried out a linear stability analysis of the former kinetic theoretical solution [J. T. Jenki ns and M. W. Richman, J. Fluid. Mech. 171, 53 (1986)] and found it to be un stable. The effect of this asymmetry on the self-diffusion coefficient is a lso discussed.