Local flow boiling performance comparison of two increasing density heatsinks

Flow boiling is a promising cooling technique for next-generation thermal management due to its high heat flux capability and improved temperature uniformity. Variable density heatsinks have emerged as a cooling design strategy for their ability to redistribute two-phase flow and enhance flow stabil...

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Detalles Bibliográficos
Autores: Camarasa Falip, Jaume, Vilarrubí, Montse, Rosell, Pol, Ibáñez, Manuel, Barrau, Jérôme
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:dnet:recercat____::af93cbe78259ae2879cedb6b5a3ae5ad
Acceso en línea:https://doi.org/10.1016/j.applthermaleng.2026.130914
https://hdl.handle.net/10459.1/469987
Access Level:acceso abierto
Palabra clave:Flow boiling
Microchannels
Pin-fins
Jet-impingement
Descripción
Sumario:Flow boiling is a promising cooling technique for next-generation thermal management due to its high heat flux capability and improved temperature uniformity. Variable density heatsinks have emerged as a cooling design strategy for their ability to redistribute two-phase flow and enhance flow stabilization. This experimental work tested two novel microstructured designs: increasing variable density pin-finned surface (PF) and a short stepwise varying width microchannel configuration (S-SVW-Mchs). Using deionized water as a working fluid, two different flow rates (100 and 200 ml/min) were evaluated at a constant inlet subcooling of 30 K. The heatsinks were combined with jet-impingement technology and a tip clearance of 50 μm. An innovative local thermohydraulic assessment was obtained due to the introduction of seven thermocouples within one half of the symmetric heatsink, providing an accurate analysis. Results indicated that the PF sample achieved peak heat transfer values of 7318 W/°C·m2 at 100 ml/min (24.7 W/cm2) and 10,982 W/°C·m2 at 200 ml/min (38.65 W/cm2). For the S-SVW-Mchs, peak values were 6438 W/°C·m2 (22.72 W/cm2) and 15,541 W/°C·m2 (44.46 W/cm2). Nucleation occurred at lower wall superheats in PF (0.54–4.27 °C) than in S-SVW-Mchs (3.54–18.10 °C). In addition, PF reached higher critical heat flux levels: 32.31 vs 26.38 W/cm2 (+23% of enhancement) and 58.11 vs 50.23 W/cm2 (+16%). The microchannel sample showed higher pressure drop and more severe flow boiling instabilities than pin-fins. A boiling utilization (Bu) benchmark was carried out against the literature, confirming that this cooling device design is a promising flow boiling cooling approach.