Convection in an internally cooled fluid layer heated from below

Convection in a homogeneously cooled layer heated by a fixed temperature at the lower boundary is investigated numerically for various Rayleigh numbers Ra and Prandtl numbers Pr. The upper boundary is kept insulating. Large aspect ratios up to 20 are used in order to study the large scale pattern of convection. The problem is mathematically identical with the problem of a homogeneously heated convection layer cooled from above. The mean temperature difference between the two boundaries decreases in proportion to Ra-0.216.