Performance evaluation of architected multi-morphological TPMS structures for liquid-cooled heat sinks

Efficient thermal management of high-heat-flux electronics in data centers increasingly relies on compact liquid-cooled heat sinks. This study investigates the thermo-hydraulic performance of uniform and multi-morphological triply periodic minimal surface (TPMS) heat sinks fabricated via laser powder bed fusion, using Diamond, Gyroid, FRD, and modified G-Prime 1 unit cells at 30% volumetric density. Conjugate heat transfer simulations ( 𝑘 – ɛ turbulence model with enhanced wall treatment) considering constant heat-source temperature of 50 °C, X-ray microscopy-based computed tomography (XRM-CT) assessment of manufacturing fidelity, and experimental pressure-drop trend verification were performed for water coolant at volumetric flow rates of 0.2–1.2 L/min (Re ≈ 75–785). Simulation results reveal that multi-morphological architectures can produce synergistic or discordant thermal effects depending on topology pairing and heat-source orientation. According to numerical predictions, the Diamond-FRD configuration achieves the highest heat transfer rate (354 ± 25 W at 1.2 L/min) while reducing pressure drop by up to 67% compared to uniform FRD. In contrast, modified G-Prime 1-FRD hybrid exhibits inferior thermal performance relative to both parent structures. Positioning the higher-performing TPMS morphology adjacent to the heat source improves overall heat dissipation across all multi-morphological pairs and flow conditions investigated. XRM-CT analysis confirms acceptable print fidelity for Diamond-, Gyroid-, and FRD-based structures, whereas thin-walled regions (below 0.25 mm) in some multi-morphological modified G-Prime 1 geometry violate current LPBF minimum feature-size limits, leading to defects in fabrication. The findings, as predicted by validated computational fluid dynamics (CFD) simulations, demonstrate that strategic morphological hybridization and orientation optimization offer tunable tradeoffs between heat transfer enhancement and hydraulic penalty, contributing useful insights for the design of next-generation compact liquid-cooled heat sinks.