Abstract
We report about an intriguing boiling regime occurring for small heaters embedded on the boundary in subcooled water. The microheater is realized by focusing a continuous wave laser beam to about in diameter onto a 165-nm-thick layer of gold, which is submerged in water. After an initial vaporous explosion a single bubble oscillates continuously and repeatedly at several albeit with constant laser power input. The microbubble's oscillations are accompanied with bubble pinch-off, leading to a stream of gaseous bubbles in the subcooled water. The self-driven bubble oscillation is explained with a thermally kicked oscillator caused by surface attachment and by the nonspherical collapses. Additionally, Marangoni stresses induce a recirculating streaming flow which transports cold liquid towards the microheater, reducing diffusion of heat along the substrate and therefore stabilizing the phenomenon to many million cycles. We speculate that this oscillate boiling regime may overcome the heat transfer thresholds observed during the nucleate boiling crisis and offers a new pathway for heat transfer under microgravity conditions.
- Received 10 April 2016
- Revised 29 August 2016
DOI:https://doi.org/10.1103/PhysRevFluids.2.014007
©2017 American Physical Society