Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA.
Phys Rev E. 2018 Jul;98(1-1):013103. doi: 10.1103/PhysRevE.98.013103.
At high temperatures, a droplet can rest on a cushion of its vapor (the Leidenfrost effect). Application of an electric field across the vapor gap fundamentally eliminates the Leidenfrost state by attracting liquid towards the surface. This study uses acoustic signature tracking to study electrostatic suppression of the Leidenfrost state on solid and liquid surfaces. It is seen that the liquid-vapor instabilities that characterize suppression on solid surfaces can be detected acoustically. This can be the basis for objective measurements of the threshold voltage and frequency required for suppression. Acoustic analysis provides additional physical insights that would be challenging to obtain with other measurements. On liquid surfaces, the absence of an acoustic signal indicates a different suppression mechanism (instead of instabilities). Acoustic signature tracking can also detect various boiling patterns associated with electrostatically assisted quenching. Overall, this work highlights the benefits of acoustics as a tool to better understand electrostatic suppression of the Leidenfrost state, and the resulting heat transfer enhancement.
在高温下，液滴可以停留在其蒸汽的垫子上（莱顿弗罗斯特效应）。在蒸汽间隙施加电场从根本上通过将液体吸引到表面上来消除莱顿弗罗斯特状态。本研究使用声信号跟踪来研究静电抑制固体和液体表面上的莱顿弗罗斯特状态。可以看出，可以通过声学检测到抑制固体表面上的莱顿弗罗斯特状态的液-汽不稳定性。这可以作为用于抑制所需的阈值电压和频率的客观测量的基础。声学分析提供了其他测量方法难以获得的附加物理见解。在液体表面上，没有声学信号表明存在不同的抑制机制（而不是不稳定性）。声信号跟踪还可以检测与静电辅助淬火相关的各种沸腾模式。总的来说，这项工作强调了声学作为一种工具的优势，可用于更好地理解静电抑制莱顿弗罗斯特状态以及由此产生的传热增强。
