Convection driven by a horizontal temperature gradient in a confined aqueous surfactant solution: the effect of noncondensables

Buoyancy–thermocapillary convection in liquid layers undergoing phase change driven by a horizontal temperature gradient in a sealed cavity in the near-absence of noncondensables is a flow relevant to evaporative cooling. Yet most of the experimental studies have instead considered convection under air at ambient pressures. Convection driven by buoyancy and Marangoni effects in a ~0.3-cm-deep layer of an aqueous surfactant solution in a closed rectangular test cell was therefore studied using particle image velocimetry. Convection under air at ambient conditions was compared with that under conditions where the gas phase was dominated by water vapor. The initial results suggest that noncondensables have a significant effect on the liquid-phase flow.