Oscillatory instability in a driven granular gasE. Khain and B. Meerson
Racah Institute of Physics, Hebrew University of Jerusalem - Jerusalem 91904, Israel
(Received 25 July 2003; accepted in final form 12 November 2003)
We discovered an oscillatory instability in a system of inelastically colliding hard spheres, driven by two opposite "thermal" walls at zero gravity. The instability, predicted by a linear stability analysis of the equations of granular hydrodynamics, occurs when the inelasticity of particle collisions exceeds a critical value. Molecular-dynamics simulations support the theory and show a stripe-shaped cluster moving back and forth in the middle of the box away from the driving walls. The oscillations are irregular but have a single dominating frequency that is close to the frequency at the instability onset, predicted from hydrodynamics.
45.70.-n - Granular systems.
45.70.Qj - Pattern formation.
© EDP Sciences 2004