Swing-like pool boiling on nano-textured surfaces for microgravity applications related to cooling of high-power microelectronics

Abstract

Here, we demonstrate that heat removed in pool boiling from a heater mimicking high-power microelectronics could be used to facilitate a swing-like motion of the heater before being finally dissipated. This swing-like motion could be beneficial for shedding a large vapor bubble that encapsulates high-power heaters in microgravity where buoyancy force is unavailable for vapor bubble removal. The swing-like motion is propelled by vapor bubble recoil, the force which exists irrespective of gravity and buoyancy. We also demonstrate that this force could be significantly enhanced by depositing on the heater surface supersonically blown polymer nanofibers with cross-sectional diameters below 100 nm. These nanofibers provide additional nucleation sites, resulting in much more frequent bubble nucleation and departure, and thus a higher overall vapor recoil force propelling the heater motion. Such nanofibers strongly adhere to the heater surface and withstand prolonged harsh pool boiling. The measured velocity of the model swing-like heater in Novec 7300 fluid is about 1 cm/s.

Experimental study on pool boiling in a porous artery structure

“…Based on the hydrodynamic instability model, recent studies regarding the effects of the heating surface characteristics made some modifications considering the surface wettability [10][11][12][13][14][15], contact angle [16][17][18], and capillary wicking [1λ-20]. In order to study these parameters, some optimization measures were presented, such as using surface coating [21][22][23][24][25][26][27][28] to change the surface wettability and contact angle, adopting porous structures [2λ-33] to enhance the capillary force and utilizing nano/micro grooved surfaces [34][35][36][37][38][39][40][41][42][43][44][45] to change the morphology of the heated surface.…”

Investigation of Structure-Property-Boiling Enhancement Mechanisms of Copper/Graphene Nanoplatelets Coatings

“…The mechanisms underlying enhanced pool boiling heat transfer have been investigated in past few decades for efficient design of reboilers (Thome, 1988;Lavrikov et al, 2015), heat exchangers (Antonelli and O'Neill, 1981;Ohta et al, 2004), power electronics (Kercher et al, 2003;Wei et al, 2009;Sadaghiani et al, 2017;Sinha-Ray et al, 2017;Zhang et al, 2018;Chauhan and Kandlikar, 2019), and other high temperature engineering applications (Konishi and Mudawar, 2015;Mudawar, 2017). This is attributed to high heat transfer efficiencies or heat dissipation exhibited by pool boiling due to the absorption of large amount of latent heat which is accompanied by phase change from liquid to vapor (Kandlikar, 2019;Amalfi et al, 2020).…”

Forced vibration of a heated wire subjected to nucleate boiling

“…Despite such a limitation as the CHF, the high heat removal rate provided by nucleate boiling is vital for multiple applications, such as nuclear reactor cooling, metallurgical quenching [1], and cooling microelectronics in ground and space applications [2][3][4][5], among others. To improve the output and facilitate usage of microelectronic devices, transistors are miniaturized.…”