考虑表面形貌影响的八隅体点阵结构换热性能优化设计方法研究

The octet lattice structure，due to its significant enhancement in heat transfer performance，has become the preferred structure for the thermal management systems of next-generation hypersonic aerospace engines. Constrained by manufacturing precision and machinability，the octet lattice structures fabricated through additive manufacturing possess complex surface topographies. However，the mechanisms by which these surface topographies affect heat transfer performance have not been fully elucidated. To this end，a numerical simulation method for the heat transfer and flow characteristics of octet lattice structures was established in this study. The mechanisms by which surface morphology affected the heat transfer of octet lattices were elucidated，and the impact degree on the heat transfer effectiveness of unit cells with different sizes was quantified. On this basis，an optimization design method for octet lattice structures considering the impact of surface morphology was established using response surface methodology and differential evolution algorithm. The results indicate that rough surfaces enhance convective heat transfer and promote fluid mixing，leading to increases in the Nusselt number and friction factor by up to 4.4% and 25%，respectively. Compared to the ideal lattice structure，the optimal lattice structure that considers the effects of rough surfaces achieves a 3% weight reduction while maintaining the same heat transfer performance.