面向金属泡沫散热器设计的自然对流拓扑优化  

Design of Metal Foam Heat Sinks Guided by the Topology Optimization of Natural Convection

作　　者：罗纪旺 陈黎[1] 郑鑫建 杨骐瑞 陶文铨[1] LUO Jiwang;CHEN Li;ZHENG Xinjian;YANG Qirui;TAO Wenquan(Key Laboratory of Thermo-Fluid Science and Engineering of MOE,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学热流科学与工程教育部重点实验室,西安710049

出　　处：《西安交通大学学报》2024年第10期72-82,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52376074)。

摘　　要：针对传统方块型金属泡沫散热器散热效率不高,难以满足高功率电子器件散热需求的问题,发展了基于格子Boltzmann和水平集方法的三维拓扑优化方法。首先,采用格子Boltzmann方法求解多孔介质内的流动和传热过程;然后,采用伴随格子Boltzmann方法计算梯度;最后,根据反应-扩散方程更新水平集函数。通过对底部放置发热元件方腔的自然对流过程开展拓扑优化,得到特征格拉晓夫数为2.4×10^(2)~1.2×10^(5)的4种优化散热器结构,定量评估了散热器的强化换热性能并分析相关机理。研究结果表明:随着格拉晓夫数的增大,散热主导机制由热传导转变为热对流,优化结构由伸展的树枝状向收缩的花朵状结构转变,以留出更多空间使得流动涡旋充分发展;与传统的金属泡沫方块结构和开槽的金属泡沫块结构相比,所提优化结构表现出优异的散热性能,其分支结构和中空结构能够优化方腔内的流动,从而将散热效率提升了29.7%以上,表明了所提拓扑优化方法的有效性。研究工作可为新型金属泡沫散热器的设计提供理论指导。To overcome the challenges of low heat dissipation efficiency in traditional block-type metal foam heat sinks and their inability to meet the cooling requirements of high-power electronic devices,a three-dimensional topology optimization method based on the lattice Boltzmann and level set methods is developed.Firstly,the lattice Boltzmann method is employed to simulate the flow and heat transfer processes within the porous medium.Then,the adjoint lattice Boltzmann method is used to calculate the gradients.Finally,the level set function is updated based on the reaction-diffusion equation.By conducting topology optimization of the natural convection process in a square cavity with heat-generating elements at the bottom,four optimized heat sink structures with characteristic Grashof numbers ranging from 2.4×10^(2)to 1.2×10^(5)are obtained.The enhanced heat transfer performance of the heat sinks is quantitatively evaluated,and the underlying mechanisms are analyzed.The research findings indicate that as the Grashof number increases,the dominant heat transfer mechanism shifts from conduction to convection.The optimized structures transform from extended branching patterns to compact flower-like structures,creating additional space for the development of more flow vortices.Compared with traditional block-shaped metal foam structures and slotted metal foam block structures,the proposed optimized structures demonstrate superior heat dissipation performance.The branch structures and hollow structures optimize the flow within the cavity,resulting in an improvement in heat dissipation efficiency of over 29.7%.These results highlight the effectiveness of the proposed topology optimization method and provide theoretical guidance for the design of novel metal foam heat sinks.

关 键 词：散热器设计 强化换热 伴随格子Boltzmann方法 金属泡沫 拓扑优化 

分 类 号：TK414.2[动力工程及工程热物理—动力机械及工程]