Existence and homogenization of the Rayleigh-Benard problem

The Navier-Stokes equation driven by heat conduction is studied. As a proto type we consider Rayleigh-Benard convection, in the Boussinesq approximatio n. Under a large aspect ratio assumption, which is the case in Rayleigh-Ben ard experiments with Prandtl number close to one, we prove the existence of a global strong solution to the 3D Navier-Stokes equation coupled with a h eat equation, and the existence of a maximal B-attractor. A rigorous two-sc ale limit is obtained by homogenization theory. The mean velocity field is obtained by averaging the two-scale limit over the unit torus in the local variable.