NUMERICAL STUDY OF DOUBLE-DIFFUSIVE NATURAL-CONVECTION IN A SQUARE CAVITY

Steady-state thermosolutal convection in a square cavity filled with air, submitted to horizontal temperature and concentration gradients, is studied numerically. In the first series of numerical simulations, the influence of solutal buoyancy force on heat or mass transfer rate is investigated: Lewis and thermal Rayleigh numbers are kept constant (Le = 1, Ra(T) = 10(7)), solutal Rayleigh number is varied (Ra(S) = 10(5)-5 x 10(7)). The second series deals with the influence of Lewis number on fluid motion for heat transfer driven flow (Ra(T) = 10(7), Ra(S) = 0) and mass transfer driven flow (Ra(T) = 0, Ra(S) = 10(7)) configurations. Lewis number is varied from 0.3 to 5. Correlations are obtained between heat and mass transfer rates and the non-dimensional numbers characterizing both phenomena.