Conjugate study on heat transfer enhancement of a TPMS-based hybrid heat sink design

Conventional heat sink designs have reached a bottleneck, necessitating the exploration of revolutionary strategies to push the performance limit. The present study examines the Schwartz-D structure as an alternative heat sink geometry in liquid cooling both numerically and experimentally. By introducing the heat penetration ratio (epsilon(e)), the research quantitatively reveals that the thermal performance improvement of the Schwarz-D topology is governed by enhanced cross-sectional coolant mixing in the intertwined interior compared with conventional heat sinks. Based on such analyses, the current work proposes a novel hybrid design with alternate pin fins and Schwarz-D structures, integrating advantages of conductive dissipation at low epsilon(e) and convective mixing at high epsilon(e). Additional conjugate thermal performance analyses are conducted with Biot number (Bi) varying from 0.02 to 4.5 and validated by experimental measurements. The result indicates that Schwartz-D structures outperform pin fins with a 24 % thermal resistance reduction and a 73 % temperature uniformity improvement when the heat transfer is dominated by flow convection at high Bi, but attenuates to a comparable level as solid conduction becomes overriding at low Bi. The newly proposed hybrid design further augments heat transfer by 14 % and enhances temperature uniformity by 51 % in comparison with the Schwarz-D structures, meanwhile effectively extending the advantageous Bi range. The present work demonstrates the vast potential of synergizing conventional and advanced fin structures for heat transfer enhancement and offers methodological guidance to flowmixing-based heat sink designs.