ONSET OF THERMOSOLUTAL CONVECTION IN A LIQUID LAYER HAVING DEFORMABLE FREE-SURFACE .1. STATIONARY CONVECTION

The effect of surface deformation on the onset of thermosolutal convection in a horizontal thin layer heated from below and salted from above is examined, using linear stability theory. It is found that two critical Crispation numbers Cr1 and Cr2 exist. For Cr less-than-or-equal-to Cr1 the instability mechanism remains uneffected by the deformation of the free-surface, whereas for Cr1 < Cr < Cr2 the critical Marangoni number (M(c)) decreases, showing instability due to deformation. If Cr = Cr2, M(c) is obtained for two values of the wave number. When Cr > Cr2, M(c) decreases as the wave number tends to zero. Further. the effect of the Marangoni number, Biot number, Bond number etc. on the stability characteristics of the problem is discussed.