Momentum Conservation and Condensing Vapor Bubbles

Boiling is a common feature of many daily processes, such as making tea, cooking, and heating. The growth, rise, collapse, and final disappearance of vapor bubbles are ubiquitous features of nucleate boiling. New experimental observations show that a vortex is generated as a consequence of the bubble disappearing. We categorize the possible mechanisms that lead to the generation of a vortex by bubbles. When the bubble collapses but does not change topology, the vortex is created by viscous effects, where the attached wake behind the vapor bubble persists after the bubble has disappeared. But when the bubbles collapse so rapidly that they change topology, the vortex is created by an inviscid mechanism. The total momentum communicated to the flow by the collapse processes is calculated and compared with the measurements of the vortex impulse. [DOI:10.1115/1.4001604]