Topological optimization design of micro-pin fin heat sinks for high heat flux cooling application

Micro-pin fin heat sinks (MPFHSs) have shown remarkable advantages for high heat flux cooling applications due to their effectiveness in enhancing thermal performance. Topology optimization further yields more compact and efficient thermal designs. In this study, a variable density topology optimization is developed to figure out the optimal material distribution and micro-pin fin geometric structures in a liquid-cooled heat sink. The topological methodology is firstly validated by comparing the 2D topology optimization with the 3D numerical simulation. The effect of fluid volume fraction V_f, porosity ε and diameter D of the micro-pin fin array is then discussed to achieve the optimal design parameters. Finally, the superiority and potential of the topology-optimized MPFHS are thoroughly discussed by comparing it with two traditional MPFHS: one without a main channel and one with six straight main channels. The results show that the optimal design parameters are V_f = 17.5 %, ε = 0.5 and D = 300 μm. Compared to the two traditional designs, the optimized MPFHS achieves 89 % and 97.6 % reductions in pumping power while achieving the same thermal performance. Besides, the optimized MPFHS can effectively manage a heat flux of 400 W/cm2 while maintaining a total pumping power of just 118.9 W. These results are of great significance to the design of advanced MPFHS for chip cooling.