Thermal convection in a granular gas of hard disks system limited by dissipative lateral walls, under zero gravity.

We have studied the properties of the thermal convection in a granular system with no gravity (i.e., g = 0); this 2D gas is enclosed by a rectangular region provided with a pair of walls acting as kinetic energy source and other two walls (“lateral” walls) characterized by inelastic wall-particle collisions (and with a coefficient of normal restitution for wall-particle collisions α_w).

If the lateral walls are elastic, the system shows a hydrostatic steady base state. On the contrary, when the α_w<1; (i.e., the lateral walls are disspiative), an additional gradient is generated. This new gradient is perpendicular to the thermal gradient coming from the temperature sources. We show the combined action of both thermal gradientes creates a convective steady base state, even if there is no gravity; i.e., this new granular convection is not buoyancy-driven.

In our presentation, we show a convection diagram as a function of α_w, for differents values of the coefficient of normal restitution α between particle collisions.