Point heat sink induced by droplet train impingement
Choo, Fook Hoong
Date of Issue2017
School of Mechanical and Aerospace Engineering
Energy Research Institute
A point heat sink is produced by impinging a high frequency microscale droplet stream onto a superheated copper substrate. Although the overall target surface area is larger than the liquid-solid interface by two or three orders of magnitude, the thermal energy is mainly removed through the point heat sink rather than the rest dry area. Therefore, the spherical conduction patterns in the solid materials are observed with a “nozzle-shifting” method which requires only two temperature probes. The temperature gradient in the vicinity of the impingement stagnation point is tremendously high, suggesting that the liquid-solid interface temperature is significantly lower than the far-field bulk temperature of the substrate. Moreover, the liquid-to-solid heat transfer is measured, which agrees well with the theoretical prediction. The maximum interface heat flux can reach around 80 W/mm2. It is insensitive to the substrate temperature in a relatively wide temperature range, which brings conveniences to the potential industrial applications.
Applied Physics Letters
© 2017 American Institute of Physics (AIP). This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of American Institute of Physics (AIP). The published version is available at: [http://dx.doi.org/10.1063/1.4983463]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.