基于不动点迭代的自然对流热沉拓扑优化  

Topology Optimization of Natural Convection Heat Sink Based on Fixed Point Method

作　　者：吴璇 陈群[1] WU Xuan;CHEN Qun(Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Department of Engineering Mechanics,Tsirghua Uriversity,Beijing 100081,China)

机构地区：[1]清华大学工程力学系,热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2020年第9期2241-2246,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51836004)。

摘　　要：自然对流热沉广泛应用于需要在室外长期稳定工作的散热场合,但温度场和流场的高度耦合增加了热沉设计的难度。本文以电子器件自然对流热沉为研究对象,以电子器件的平均温度最低为优化目标,建立自然对流热沉结构拓扑优化模型。基于[火积]耗散极值原理,利用变分法导出了自然对流换热过程的欧拉方程,构造显式不动点迭代格式,对自然对流热沉结构进行优化,获得了性能最优的自然对流热沉设计。计算结果表明,在Gr数较低时,树状分叉结构热沉性能最佳;在Gr数较高时,尖峰状结构热沉性能最佳。Natural convection heat sinks are widely used in long-term stable outdoor cooling occasions.However,the strong coupling between the temperature field and the flow field brings great difficulties to the design of the natural convection heat sink.In this paper,the natural convective heat sink of electronic devices is studied and the topology optimization model of natural convection heat sink structure is established with the aim of minimizing the average temperature of the electronic device.Based on the entransy dissipation extremum principle,and the Euler-Lagrange equation is derived by calculus of variations,which is corresponding to the optimal structure of natural convective heat sink.A fixed point iteration format is constructed to optimize the structure of the natural convective heat sink,and the optimal heat sinking designs are obtained.The optimal heat sink designs under different working condition shows that tree-like heat sink is the optimal design structure at low Grashof number,while spike like heat sink is the optimal design structure at high Grashof number.

关 键 词：优化准则法 自然对流 [火积]耗散极值原理 拓扑优化 

分 类 号：TK124[动力工程及工程热物理—工程热物理]