The Effect of a Salinity Gradient on the Instability of Natural Convection in a Vertical Fluid Layer

The effect of a salinity gradient on the instability of natural convection in a vertical fluid layer between two parallel plates is investigated theoretically. Temperatures of the two plates are different by 2T0 and both a stable temperature gradient, β>0, and an unstable salinity gradient, β>0, are present in the vertical direction. The stability is investigated for various values of P and in the case of the Prandtl number Pr = 7 and the Schmidt number Sc = 700, which corresponds to weak salt water. It is found that the stationary mode dominates the onset of instability if both β and are moderate, otherwise the travelling mode governs it.