Numerical investigation of nucleate boiling heat transfer on thin substrates
Numerical investigation of nucleate boiling heat transfer on thin substrates
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DOI：
10.1016/j.ijheatmasstransfer.2014.04.026
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发表时间：
2014-09
影响因子：
5.2
通讯作者：
A. Sanna;C. Hutter;D. Kenning;T. Karayiannis;K. Sefiane;R. A. Nelson
中科院分区：
文献类型：
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作者：
A. Sanna;C. Hutter;D. Kenning;T. Karayiannis;K. Sefiane;R. A. Nelson
本文的目的是定义的指导方针，为新的沸腾试验段的设计与大量的人工核化的网站在核态沸腾薄基板水平浸没在饱和液体与位于上表面的人工空腔。在实验分析的基础上，对单个汽泡和多个形核点的池沸腾换热进行了数值模拟。在实验中使用了专门的测试部分，用于研究沸腾机制和活性部位之间的相互作用，以便改进代表问题物理学的数值模型。本研究中使用的代码的混合性质，以简化的方式将固体基质中三维随时间变化的能量方程的完整解与代表液体侧发生的物理现象的半经验模型相结合，允许大量的模拟在一个合理的计算时间。本论文的重点是在第一部分的能力，该模型重现实验结果的各种条件下，而在第二部分中，大量的成核位点的结果进行了分析。关于单个气泡的生长，本文将提出两个系列的模拟：第一个分析的核沸腾的机制浸没在介电流体FC-72的硅衬底上。第二个系列研究了在饱和水中，铂和钛金属基底上气泡的行为。在最后一节中，一个网站的位置在一个大的人口的网站（100的顺序）上的等待时间，生长时间，类型和发生的聚结和热特性的模拟过程中的效果。
The objective of this paper is to define the guidelines for the design of new boiling test sections with a large number of artificial nucleation sites during nucleate boiling for thin substrates horizontally immersed in a saturated liquid with artificial cavities located on the upper surface. The findings of numerical simulations of pool boiling heat transfer for a single bubble and for a large number of nucleation sites based on the analysis of experimental cases were analysed. Dedicated test sections were used in experiments for the study of boiling mechanisms and interactions between active sites so that the numerical models representing the physics of the problem could be improved. The hybrid nature of the code used in this study, combining the complete solution of the three-dimensional time-dependent energy equation in the solid substrate with semi-empirical models representing the physical phenomena occurring in the liquid side, in a simplified way, allows a large number of simulations in a reasonable computational time.The present paper focuses in the first part on the capability of the model to reproduce the experimental results for various conditions, while in the second part, the results for a large number of nucleation sites are analysed. Regarding the single bubble growth, two series of simulations will be presented in this paper: the first one analyses the mechanisms of nucleate boiling on a silicon substrate immersed in the dielectric fluid FC-72. The second series studies the behaviour of bubbles on metallic substrates, platinum and titanium, in saturated water. In the last section, the effect of the position of a site during simulations of a large population of sites (of the order of 100) on the waiting time, growth time, type and occurrence of coalescence and the thermal characteristics is presented.