Lo, Ching-WenChing-WenLoSyu, Po-YaoPo-YaoSyuWang, Chen-KuangChen-KuangWangYA-YU CHIANG2026-03-162026-03-162026-03-1503605442https://www.scopus.com/record/display.uri?eid=2-s2.0-105029384996&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/736369This study investigates the influence of helix structure arrays on saturated pool boiling performance through a systematic parametric evaluation of helix height and density. A total of seven copper-based surfaces, including one flat baseline and six helix-structured configurations, were tested in distilled water under atmospheric pressure. The results demonstrate that appropriately designed helix structures can simultaneously enhance the critical heat flux (CHF) and the heat transfer coefficient (HTC) by up to 78% and 164%, respectively. These enhancements are attributed to the combined effects of shortened bubble residence time, increased bubble departure height, and intensified local convective flow fields. High-speed imaging revealed that taller helix arrays facilitate vapor column detachment and reduce vapor accumulation above the heated surface, while particle image velocimetry (PIV) confirmed the presence of accelerated upward fluid motion induced by vapor ejection and capillary-driven liquid return. These findings underscore the critical role of helix geometry in manipulating interfacial bubble dynamics and promoting liquid–vapor separation, offering promising insights for the thermal design of advanced boiling surfaces.falseBubble dynamicsCritical heat fluxHeat transfer coefficientHelix structuresParticle image velocimetryPool boilingjournal article10.1016/j.energy.2026.1403222-s2.0-105029384996