层次脉状结构液冷均温板优化设计研究

Study on Optimal Design of Liquid Cooling Uniform Temperature Plate Embedded with Hierarchical Vein Structure

由于耐热型植物具有良好的传热传质能力,结合流道拓扑优化设计和耐热型植物高级脉序的叶脉结构特征,提出一种层次脉状结构液冷均温板的设计方法。以热交换最大和流阻最小为目标开展主流道拓扑优化设计,提取胡杨叶高级脉序的结构特征,形成液冷均温板的次流道。定义结构像素密度作为描述次流道中孔的密度参数,分析其对层次脉状结构液冷均温板的传热传质性能的影响。研究结果表明,层次脉状结构的液冷流道具有较小的流阻和良好的均温性,同时主、次流道尺寸存在最优匹配。进一步研究胡杨叶脉的分布规律,发现液冷板主、次流道尺寸最优匹配规律与胡杨叶低、高级脉序尺寸匹配规律相近。研究结果不仅为液冷均温板的设计提供新思路,而且验证了耐热植物叶脉结构特征对其传热传质性能产生的正面影响。最后加工液冷板,通过试验验证了设计方法的有效性及数值模拟的准确性。

Inspired by the leaf veins of the heat-resistant plants, by incorporating the topology optimization design technique with the hierarchical liquid-cooling channels, an optimal design methodology for the liquid-cooled heat sink is proposed. First, the main branch channel layout is generated by maximizing the heat exchange and minimizing the flow resistance based on topology optimization. Secondly, the local features of the populus euphratica leaf are extracted and they are integrated into the obtained channel layout to generate the sub-branch channels. A newly defined “structure pixel density” can be used to describe the porosity of the channel. This porosity can affect the global flow and thermal performances of the heat sink. The results show that the hierarchical cooling channel has a lower power dissipation while it can provide a better temperature uniformity, and the optimal matching of the main and sub-branches can be observed. By further studying the distribution pattern of the leaf veins, it can be observed that the cooling channels and the leaf veins share some similarities in appearance. This work not only provides a new insight into the design of liquid-cooled heat sink, but also reveals the positive effect of the leaf vein patterns on their heat and mass transfer. Finally, the flow and thermal performances of the heat sinks are investigated experimentally. The experimental results show a good correspondence with the numerical results. Hence, the effectiveness of the proposed design method is validated.