论文标题
通过局部焦耳加热在纳米孔中沸腾：成核与薄膜沸腾之间的过渡
Boiling in Nanopores through Localized Joule Heating: Transition between Nucleate and Film Boiling
论文作者
论文摘要
从微/纳米纹理表面上的核沸腾到膜的过渡至关重要，在许多实际应用中，需要避免它来实现安全有效的热传递。先前的研究集中在宏观上的过渡过程上，在该过程中，在一系列微型/纳米结构上激活了传热和气泡的产生。在本研究中，我们将研究量表缩小到单个纳米孔，在该纳米孔中，通过孔隙体积内的局部焦耳加热，在纳秒分辨率下使用电阻脉冲传感和声学感测检查了单毛的成核和过渡。类似于宏观沸腾的沸腾，在纳米孔的情况下，异质气泡可以对膜成核并聚集到膜中，因此，在圆柱孔表面上成核的异质气泡斑块可以形成圆环形的蒸气膜，覆盖整个孔表面。与常规池沸腾相反，纳米孔沸腾涉及一种反向过渡机制，随着热量产生的增加，膜沸腾恢复为核沸腾。随着整个纳米孔的偏置电压的增加，焦油的热量产生在孔内增加，从而导致圆环形蒸气膜的不稳定和崩溃。
The transition from nucleate to film boiling on micro/nano textured surfaces is of crucial importance in a number of practical applications, where it needs to be avoided to enable safe and efficient heat transfer. Previous studies have focused on the transition process at the macroscale, where heat transfer and bubble generation are activated on an array of micro/nanostructures. In the present study, we narrow down our investigation scale to a single nanopore, where, through localized Joule heating within the pore volume, single-bubble nucleation and transition are examined at nanosecond resolution using resistive pulse sensing and acoustic sensing. Akin to macroscale boiling, where heterogeneous bubbles can nucleate and coalesce into a film, in the case of nanopores also, patches of heterogeneous bubbles nucleating on the cylindrical pore surface can form a torus-shaped vapor film blanketing the entire pore surface. In contrast to conventional pool boiling, nanopore boiling involves a reverse transition mechanism, where, with increased heat generation, film boiling reverts to nucleate boiling. With increasing bias voltage across the nanopore, the Joule heat production increases within the pore, leading to destabilization and collapse of the torus-shaped vapor film.
