Hydrodynamic description of an open fluidized granular gas

Javier Brey

Facultad de Física 7 Física Teórica, University of Sevilla, Apartado de Correos 1065, 41080 Sevilla, Spain

The steady state of an open vibrated granular gas is studied by using the hydrodynamic description to Navier-Stokes order. It is shown that, as a function of the height, the density profile presents a maximum while the temperature exhibits a minimum, so that it increases with the height beyond it. This peculiar behaviour is associated with the existence of a contribution to the heat flux due to the density gradient, which has no analogous in molecular gases. In fact, the new transport coefficient can be obtained from the measurement of the heat flux at the temperature minimium. A good agreement is found between the results from particle simulations and the theoretical predictions derived from the Boltzmann equation. The problem of the upper boundary condition to be used when solving the hydtrodynamic equations for the system is addressed. Also, the existence of some inestabilities recently discovered will be shortly discussed.