Thermosolutal Convection in the Presence of Both Vertical and Horizontal Temperature Gradients

Abstract

The occurrence of stationary and oscillatory solutions in a horizontal layer of fluid in the presence of horizontal and vertical temperature gradients and also in the presence of a vertical solute concentration gradient is investigated. The critical Rayleigh number for oscillatory and stationary solutions is derived numerically for a wide range of values of parameters and it is found that the marginal state is of periodic character in almost all the cases except for very small values of horizontal temperature gradient, solute gradient, and Prandtl number. The effect of horizontal gradient of temperature on the stability of the system is both stabilizing as well as destabilizing. For a large value of horizontal temperature gradient the system first exhibits oscillatory motion and in subsequent time oscillations die down.