扩展表面型热源/沉的多尺度构形优化及强化传热机制研究

The structure optimizations of the heat sources/sinks with extended surfaces have attracted a great deal of attention in many fields such as electronics cooling, and their development trends of multi-scale optimizations have appeared. This project focuses on the multi-scale constructal optimizations of heat sources/sinks with extended surfaces and mechanism investigations of enhanced heat transfer by combining principle of entropy generation minimization, extremum principle of entransy dissipation, field synergy theory with constructal theory, employing various optimization criterias and objectives respectively and using the methods of mathematical analyse, numerical calculation and experimental investigation synthetically. The contents of this project include: (1) the multi-scale constructal optimizations as well as comparative investigations of the distributions of heat sources with extended surfaces based on principle of entropy generation minimization and extremum principle of entransy dissipation, respectively; (2) the multi-scale constructal optimizations as well as comparative investigations of the heat sinks with extended surfaces based on various optimization objectives including entransy dissipation, entropy generation and exergoeconomic functions; (3) the investigations on physical mechanisms of enhanced heat transfer for the items (1) and (2) by employing field synergy theory; (4) the experimental investigations based on the theoretical optimization results of the distribution of heat sources. The purposes of this project are to reveal the effects of the multi-scale characteristics on the heat transfer and flow performances of the two configurations, to illustrate the fundamental relationships between overall performances and geometric parameters, to understand the internal mechanisms of enhanced heat transfer, as well as to provide some theoretical foundations for the integrative optimal design combining performance with structure in the correlative problems of thermal design and management.

扩展表面型热源/沉的结构优化在电子散热等领域中备受关注，且呈现出多尺度化的发展趋势。本项目拟将熵产生最小化原理、(火积)耗散极值原理、场协同理论和构形理论相结合，采用多种优化准则和目标，综合运用数学分析、数值计算和实验研究的方法，开展扩展表面型热源/沉的多尺度构形优化及强化传热机制研究。内容包括：(1)分别基于熵产生最小化原理和(火积)耗散极值原理的扩展表面型热源分布的多尺度构形优化比较研究；(2)基于(火积)耗散、熵产生和(火用)经济学函数等不同优化目标的扩展表面型热沉的多尺度构形优化比较研究；(3)引入场协同理论，研究(1)、(2)项中的强化传热机制；(4)基于热源分布的理论优化结果开展实验研究。旨在揭示多尺度特性对两类结构传热及流动性能的影响规律，明晰整体性能与几何参数的基本关系，认识其内在的强化传热机制，为相关热设计与热管理问题中性能与结构的一体化最优设计提供理论依据。

扩展表面型热源/沉的结构优化在电子散热等领域中备受关注，且呈现出多尺度化的发展趋势。本项目深入开展了扩展表面型热源/沉的多尺度构形优化及强化传热机制研究，同时对相关问题进行了探索，取得了一些具有较高学术理论意义和工程应用价值的成果。主要体现在：.（1）成系列开展了各种对象的热设计优化研究，获得了基于不同优化准则的目标函数与结构几何参数的基本关系及最优构形设计方案。建立了5种三维热源模型，采用3种目标开展了扩展表面型热源构形优化。针对5种肋片热沉，分别以最大热阻最小、火积耗散率最小、换热率最大、熵产率最小和热经济函数最优为目标，开展了构形优化。针对5种通道热沉，分别以最大温差最小、火积耗散率最小和火积耗散数最小、熵产率最小和熵产比最小为优化目标，开展了构形优化。针对3种常规尺度下和4种微、纳米尺度下的高导热材料分布、立式绝热壁和轧钢加热炉壁平板绝热层两种隔热材料、盘点多孔介质和圆柱形构造体两种传质模型、燃料电池和电磁体进行了构形优化。.（2）丰富了多尺度构形优化研究。通过多尺度构形优化实现了圆柱体离散热源、非等高矩形直肋热沉、T-Y形肋片热沉、树形肋片热沉、线-线脉管热沉、辐射与树枝状盘点脉管热沉、对称树状盘点脉管热沉、非对称树状盘点脉管热沉、X形脉管热沉、常规尺度下和微、纳米尺度下的高导热材料分布、盘点多孔介质传质的性能强化，揭示了研究对象的多尺度特性对整体性能的影响规律。.（3）拓展了火积耗散极值原理的应用范围。将火积理论与构形理论相结合，应用于外裹肋片的圆柱体热源、圆柱体热源、T-Y形肋片热沉、树形肋片热沉、辐射与树枝状盘点脉管热沉、对称树状盘点脉管热沉、常规尺度下和微、纳米尺度下的高导热材料分布的构形优化，探明了研究对象的火积耗散与几何尺度的基本关系。.（4）发展了熵产生最小化研究。将熵产生最小化原理与构形理论相结合，应用于圆柱体单热源、圆柱体离散热源、圆柱针肋热沉、线-线脉管热沉、非对称树状盘点脉管热沉和X形脉管热沉的构形优化，实现了扩展外表面结构的熵产生最小构形优化，探明了研究对象的熵产生与几何尺度的基本关系。.（5）发展了多学科多目标构形优化。分别以立式绝热壁和电磁体为研究对象，建立复合优化目标函数开展了构形优化研究。.上述研究，增进了对事物结构寻优演化规律的认知，为相关热设计与热管理问题中性能与结构的一体化最优设计提供了理论依据。