| Mon August 20th 2018 16:00 – 17:00 ZH286 | Seminar | When Cavitation and Nucleate Boiling meet: Overcoming the Boiling Crisis Claus-Dieter Ohl |
Details:A newly discovered regime connects cavitation bubble dynamics with nucleate boiling. The heater temperatures are above the Leidenfrost temperature, yet no vapour layer is formed. The trick is to utilise microscopic heater elements and operate them in certain power regime. Then bubbles remain attached to the heater and auto-oscillate stably at hundreds of kilohertz frequency. Thereby they create a liquid flow, which counteracts heat diffusion on the substrate. The stability of the bubble oscillations is also affirmed through microbubble pinch-off to remove the collected gas. In this regime we have observed bubble oscillations of tens of millions of cycles, studied the interaction of two, three and arrays of bubbles, and proved that microgravity is not a showstopper. | ||
