Marangoni Convection Instabilities Induced by Evaporation of Liquid Layer in an Open Rectangular Pool

Abstract

In order to investigate the Marangoni convection instability of 0.65cSt silicone oil induced by evaporation in liquid layer, a series of experiments are carried out in an open rectangular pool. The effects of side wall temperature as well as ambient temperature on competitions between BM convection and thermocapillary convection are analyzed thoroughly. Increasing of the side wall temperature would inevitably enhance thermocapillary convection and suppress the formation of BM cells by transferring hot fluid from border to surface. As long as the side wall temperature is high enough, BM cells would disappear completely and multicellular rolls as well as hydrothermal waves would occur in the whole layer. Increasing ambient temperature would enhance both BM convection and thermocapillary convection, but the later one benefits more from it because hydrothermal waves can occur at a lower Ma number. Critical Marangoni numbers for the incipience of hydrothermal waves and that disappearance of BM convection cells are obtained under different ambient temperatures.