Rayleigh-Benard percolation transition study of thermal convection in porous media: Numerical simulation and NMR experiments

Thermal convection was, studied as a function of the porosity in random-sit e percolation model objects in a Rayleigh-Benard configuration. NMR velocit y mapping experiments and numerical simulations using the finite-volume met hod are compared. Velocity histograms were evaluated and can be described b y power laws in a wide range. The maximum velocity as a function of the por osity indicates a combined percolation/Rayleigh-Benard transition.