TY - JOUR
T1 - Single bubble nucleation in water-filled 59-nm nanochannel
AU - Poudel, Sajag
AU - Maroo, Shalabh C.
N1 - Funding Information:
This material is based upon work supported by, or in part by, the Office of Naval Research under contract/grant no. N000141812357. The numerical simulations were performed in the UberCloud virtual machines, an official cloud hosting partner of ANSYS.
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/7/5
Y1 - 2023/7/5
N2 - Bubble nucleation, by surface heating, is simulated in a water-filled 59 nm height silicon-dioxide nanochannel using computational fluid dynamics. Disjoining pressure of water is integrated in the continuum-level simulations to capture the molecular effects of nanoscale confinement. Input parameters of imposed heat flux and phase-transition coefficient are widely varied to perform a set of 50 simulations. Bubble nucleation occurs within a narrow temperature range of 124.7 ± 2.5 °C, and in excellent agreement with prior experimental finding. Onset of bubble nucleation occurs at the center of the channel rather than at the surface due to the presence of disjoining pressure, i.e., no three-phase contact line forms and a water film is present between the bubble and the surface. Post nucleation, three distinct paths of bubble collapse, steady-state, and continuous growth are observed, with the last case leading to formation of three-phase contact line. Such behavior is attributed to a critical thickness of the water film and associated disjoining pressure. The present work sheds light on the importance of disjoining pressure and its dominance in governing the bubble onset and growth behavior. Such fundamental understanding can potentially advance the development of future thermal management devices, such as heat pipes.
AB - Bubble nucleation, by surface heating, is simulated in a water-filled 59 nm height silicon-dioxide nanochannel using computational fluid dynamics. Disjoining pressure of water is integrated in the continuum-level simulations to capture the molecular effects of nanoscale confinement. Input parameters of imposed heat flux and phase-transition coefficient are widely varied to perform a set of 50 simulations. Bubble nucleation occurs within a narrow temperature range of 124.7 ± 2.5 °C, and in excellent agreement with prior experimental finding. Onset of bubble nucleation occurs at the center of the channel rather than at the surface due to the presence of disjoining pressure, i.e., no three-phase contact line forms and a water film is present between the bubble and the surface. Post nucleation, three distinct paths of bubble collapse, steady-state, and continuous growth are observed, with the last case leading to formation of three-phase contact line. Such behavior is attributed to a critical thickness of the water film and associated disjoining pressure. The present work sheds light on the importance of disjoining pressure and its dominance in governing the bubble onset and growth behavior. Such fundamental understanding can potentially advance the development of future thermal management devices, such as heat pipes.
KW - Bubble nucleation
KW - CFD simulations
KW - Critical film thickness
KW - Disjoining pressure
KW - Nanochannel
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U2 - 10.1016/j.applthermaleng.2023.120572
DO - 10.1016/j.applthermaleng.2023.120572
M3 - Article
AN - SCOPUS:85152743433
SN - 1359-4311
VL - 229
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
M1 - 120572
ER -