微纳结构与液核分布耦合作用下滴状冷凝传热机理研究

项目名称： 微纳结构与液核分布耦合作用下滴状冷凝传热机理研究

项目编号： No.51506184

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 梅茂飞

作者单位： 徐州工程学院

项目金额： 18万元

中文摘要： 在冷凝器表面的各种传热方式中，滴状冷凝相变传热最为高效。滴状冷凝的研究已经从宏观尺寸过渡到微观尺寸，许多新型微纳结构疏水冷凝材料正处于试验当中。目前，制约微纳结构冷凝材料的传热效率主要有两个因素：液滴润湿状态和液滴尺寸分布。两者影响滴状冷凝的传热机理目前仍不明确，有待深入研究。本课题拟首先研究微纳结构和液核分布的耦合作用对液滴润湿状态的影响，确定液滴润湿状态与表面几何参数和液核空间位置之间的关系。其次，构建微纳结构疏水表面的三维网络，采用动态网格和并行算法，模拟微纳结构疏水表面的液滴生长过程，研究液滴润湿状态对液滴尺寸分布以及滴状冷凝传热的影响，计算表面滴状冷凝的热流密度。通过本项目的研究，针对微纳结构疏水冷凝材料提出评价其传热效果的科学方法，为研制高效冷凝材料奠定理论基础。

中文关键词： 热质传递；滴状冷凝；微纳结构；数值模拟；并行算法

英文摘要： The phase-change heat transfer of dropwise condensation is the best for condenser among the different modes of heat transfer. the studied scale of the surface materials of the condenser has transferred from macroscopic to microscopic. Some new hydrophobic condensing materials with micro/nano structures have been developed and tried on in labs. Up to now, The wetting state of droplets and droplet-size distribution on condensing surface are two main factors to influence the heat transfer ability of the condensing materials with micro/nano structures. However, it is still not well understood how the heat transfer influenced by the two factors on which further investigation therefore is necessary. This project firstly will present the influence of the micro/nano structure and nucleation distribution on the wetting state of droplets. We will determine the wetting state of droplets correlated with the surface geometrical parameters and nucleation positions. Then, on 3-dimension meshes constructed according to the condensing materials with micro/nano structure, the process of droplet growth will be simulated by using dynamic grid and parallel algorithm. We will investigate the influence of the wetting state of droplets and droplet-size distribution on heat transfer, and calculate the heat transfer rate of dropwise condensation. The project is very beneficial to scientifically provide a method to evaluate the heat transfer efficiency and to design more powerful condensing materials.

英文关键词： Heat and mass transfer; Dropwise condensation;Micro and nano structure;Numerical simulation;Parallel algorithm