Abstract
The transport coefficient coupling heat flux and density gradient in a granular gas is measured by taking advantage of the existence of a minimum in the temperature profile of an open vibrated granular system. The results from particle simulations are found to be in good agreement with the theoretical predictions derived from the Boltzmann equation. The accuracy of a boundary condition requiring the hydrodynamic heat flux to vanish at infinite height is discussed, and shown to be consistent with the simulation data.