Multi-objective optimizations on thermal and hydraulic performance of symmetric and asymmetric bionic Y-shaped fractal networks by genetic algorithm coupled with CFD simulation

摘要

With the high energy output of electronic devices, effective heat dissipation with low energy consumption has drawn great attention. Based on the construction theory, the flow resistance of the generalized bionic Y-shaped fractal networks is theoretically analyzed. It is found that the symmetrical width has a positive effect on reducing the hydraulic resistance, while the symmetrical length plays a negative influence. Then, the optimal designs of symmetrical and asymmetrical bionic Y-shaped fractal heat sinks are obtained by multi-objective optimization with genetic algorithm (GA). The pressure loss in the asymmetrical bionic Y-shaped fractal heat sink is always lower than that of the symmetrical bionic Y-shaped fractal heat sink at the same fractal number. As the constraint of thermal resistance reduces from 0.045 K/W to 0.042 K/W, the pumping power difference between symmetrical and asymmetrical bionic Y-shaped fractal heat sinks increases from 70.1 mW to 99.1 mW. Furthermore, according to the CFD investigation, it is noted that the symmetrical heat sink exhibits a lower temperature difference and more uniform temperature distribution.