THE EFFECT OF THE PRANDTL NUMBER ON PENETRATIVE CONVECTION

Steady, nonlinear, penetrative convection in a viscous, incompressible fluid confined between free horizontal boundaries in two dimensions i s investigated numerically. For Prandtl numbers sigma less than unity and for fixed imposed heat flux, the resulting Rayleigh number R is-pr oportional-to sigma-1 indicating a strong dependence on the Prandtl nu mber not realised with two-dimensional Rayleigh-Benard calculations. A t low Prandtl numbers, the convection bifurcates supercritically and l ess efficient heat transport and different cell geometry are exhibited , with no ''flywheel'' solution in existence.