Research Information System
23rd IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, ITherm 2024, Colorado, United States Of America, 28 - 31 May 2024, (Full Text)
Maintaining new electronic devices within the permitted operating temperature ranges requires effective thermal management technologies. For this reason, much research has been conducted on pool boiling cooling systems for electronic chip design, power generation applications, and data center cooling systems. This study aims to increase the critical heat flux (CHF) and heat transfer coefficient (HTC) and eliminate the incipience boiling hysteresis using surface modifications. Honeycomb fin structures with microscale side gaps are manufactured by Selective Laser Melting (SLM). AlSi10Mg powder is used for this study because of its high thermal conductivity and low density. The working fluid is selected as Novec-7100, and pool boiling experiments are conducted in a saturated condition under atmospheric pressure. Surface modifications decrease boiling incipience superheat and eliminate the incipient boiling hysteresis compared to the plain surface. Side square gaps create a new path for vapor-liquid flow, and liquid replenishment becomes easier. However, the HTC of the honeycomb structure without side gaps is higher than that of other structures above 25 W/cm2 because mushroom-shaped bubbles cannot encompass the entire honeycomb structure. The surface modifications enhance HTC and delay CHF. The best-performing structure has a maximum HTC of 1.567 W/(cm2K), 2.96 times that of the plane surface at 0.530 W/(cm2K). Also, it has CHF higher than 74.29 W/cm2, which is 3.20 times that of the plane surface at 23.24 W/cm2. The pool boiling enhancement of surface modifications is attributed to the increased surface area, higher active nucleation site density, and capillary-assisted suction. The results offer significant guidance for creating future surface modifications manufactured by additive manufacturing for boiling improvement.