Stability of buoyancy and surface tension driven convection in a horizontal double-diffusive fluid layer

Linear stability analysis has been applied to examine the stability of convection in a horizontal double-diffusive fluid layer driven by the combined effects of buoyancy and surface tension. Such a convective flow may serve as an idealized model of the horizontal Bridgman process for crystallization or solidification of liquid melts. Results show that salt-finger instability is excited over a wide range of thermal and solutal Grashof numbers. Travelling wave instabilities caused by surface tension effects are excited when the effective Marangoni number becomes large.