The origin of thermocapillary convection in subcooled nucleate pool boiling
The authors investigate theoretically the significance of noncondensible gas as the origin of thermocapillary convection in subcooled pool boiling. To do it, an isolated bubble with steady-state mass flow from its bottom to top is considered. Noncondensable gas is carried along with the evaporating vapour at the base of the bubble and accumulates at its top. To ensure a steady-state mass flow through the bubble in the presence of accumulated noncondensable gas, an intensified heat transfer in the liquid is necessary, which is possible by the thermocapillary convection. By a combination of analytical and numerical approaches it is shown that conditions could be revealed, where a steady-state mass flow through the bubble is no longer possible and the bubble begins to grow into the subcooled liquid, which is in accordance with experimental observations. It is demonstrated that even small amounts of noncondensable gas are sufficient to induce thermocapillary flow which, in turn, inhibits bubble detachment. The paper is well-written and the presentation is clear.
scientific article; zbMATH DE number 1587644