翅片-泡沫铜复合结构的导热增强作用

由于翅片能够极大提高沿翅片伸展方向的导热能力,因此为满足一些航空大功率元件的散热要求,提出采用翅片-泡沫铜复合结构作为导热增强介质的概念.制作了翅片厚度分别为0.5,0.8mm和1.0mm的翅片-泡沫铜/石蜡实验件.通过瞬态和稳态的方法对实验件的热特性进行了测试,结果表明添加1.0mm翅片后复合材料的等效导热系数达到11.4W/(m·K),分别为泡沫铜/石蜡和纯石蜡的3.7倍和42.2倍;在相同热流密度下,采用翅片的装置热源与散热面的最大温差相对于未采用翅片的装置降低了73.2%~90.0%.实验证明翅片能够显著提高泡沫铜/石蜡的等效导热系数和动态热响应速度.根据实验结果提出了适用于翅片-泡沫铜/石蜡相变过程的无量纲数关联式.

Heat transfer enhancement of fin-copper foam composite structure

As the fins can significantly enhance the thermal conducting capability along the fin extending direction,the concept of combining fins with copper foam as thermal conductivity enhancer was proposed to satisfy the heat rejection requirements of some high-power electronic components used in the aviation.Fin-copper foam/paraffin samples with fin thicknesses of 0.5,0.8 and 1.0mm were processed.The thermal performances of the samples were tested via steady and transient experiments.The results suggest that the effective conductivity of composite material with 1.0mm fin reaches 11.4W/ (m·K), which is 3.7 times as that of the copper foam/paraffin and 42.2 times as that of the pure paraffin.Under the same heat flux,the maximum temperature differences of the samples with fins are reduced by 73.2%-90.0%.The tests verify that the effective thermal conductivity and the dynamic thermal response of copper foam/paraffin can be remarkably enhanced by fins.A correlation of the non-dimensional coefficients is raised via the experimental results.