拓扑优化相变热沉在不同重力场的性能

Topological optimzation of phase change heat sink performance in different gravity fields

为强化相变热沉的性能,基于带惩罚的固体各向同性材料(SIMP)法对山梨糖醇相变热沉进行传热拓扑优化设计。对拓扑优化的相变热沉(Ⅰ)和直肋式的相变热沉(Ⅱ)进行定常重力(0~20g)和周期性重力条件的数值模拟研究。利用无量纲数对比二者的热性能,研究结果表明:热沉Ⅰ的吸热和均热性能优于热沉Ⅱ;在相同重力环境下,以80℃为目标,热沉Ⅰ温控时间比热沉Ⅱ平均多26.8%;微低重力下热沉内部近乎导热,略逊于常规重力下热性能;超重力强化的自然对流可以显著提升热沉性能,10g条件相比常规重力的温控时间增加8.94%,而相同Ra^(*)下,周期性重力对热沉Ⅰ的性能有抑制作用。研究结果对飞行器载相变热沉的地面细化设计有一定指导意义。

To enhance the performance of phase change heat sink based heat sinks,the topology optimization of a sorbitol/aluminum phase change heat sink based heat sink is carried out using solid isotropic material with penalization(SIMP)method.Numerical investigations on phase change heat sink with topologically optimized fins(I)and straight fins(II)under the constant gravity(0~20g)and periodic gravity are presented.Dimensionless numbers are used to compare the thermal performance of the two heat sinks.The results show that heat sink I performs better than heat sink II.Under the same gravity environment with 80℃as the goal,the temperature control time of the heat sink I is extended by up to 26.8%on average.Under the microgravity and low gravity,heat conduction dominates the heat sinks,of which the thermal performance is slightly inferior to that under conventional gravity.The natural convection of the liquid PCM driven by supergravity significantly enhances the heat transfer.For heat sink I,the temperature control time of 10g is 8.94%higher than that of conventional gravity,and the periodic gravity has an inhibitory effect at the same Ra^(*).Research findings provide guidance for detailing the design of aircraft phase change heat sinks.