TY - JOUR

T1 - Effect of mixed wettability surfaces on flow boiling heat transfer at subatmospheric pressures

AU - Ahmadi, Vahid Ebrahimpour

AU - Guler, Tayfun

AU - Celik, Suleyman

AU - Ronshin, Fedor

AU - Serdyukov, Vladimir

AU - Surtaev, Anton

AU - Sadaghiani, Abdolali K.

AU - Koşar, Ali

N1 - This study was funded by TUBITAK ( The Scientific and Technological Research Council of Turkey ) grant no: 119N401 and RFBR ( Russian Foundation for Basic Research ) grant no: 20–58–46008 .

PY - 2024/1/5

Y1 - 2024/1/5

N2 - Subatmospheric flow boiling heat transfer is a promising method for electronics cooling due to lower saturation temperatures. However, pressure is a crucial parameter that affects surface tension and vapor density. In this study, the effect of surface mixed wettability configuration on bubble dynamics and flow boiling was investigated under atmospheric and subatmospheric pressure conditions. Superhydrophilic, superhydrophobic, and mixed-wettability surfaces were prepared and tested at various heat fluxes and three system pressures of 48 kPa, 68 kPa, and 101 kPa. The channel dimensions were 50 mm × 15 mm, and the channel had a depth of 1 mm. The results showed that biphilic surfaces enhanced the performance up to 28% compared to superhydrophilic surfaces at high heat fluxes for subatmospheric boiling. Flow visualization efforts reveal that mixed-wettability surfaces improve heat transfer by extending the efficient slug regime to higher heat fluxes by preventing dried spot formation. These surfaces benefit from high density nucleation sites at low and medium heat fluxes, resulting in a noticeable performance improvement compared to the superhydrophilic surface. The obtained experimental data in this study will be helpful for the development of thermal-fluid systems operating under subatmospheric conditions.

AB - Subatmospheric flow boiling heat transfer is a promising method for electronics cooling due to lower saturation temperatures. However, pressure is a crucial parameter that affects surface tension and vapor density. In this study, the effect of surface mixed wettability configuration on bubble dynamics and flow boiling was investigated under atmospheric and subatmospheric pressure conditions. Superhydrophilic, superhydrophobic, and mixed-wettability surfaces were prepared and tested at various heat fluxes and three system pressures of 48 kPa, 68 kPa, and 101 kPa. The channel dimensions were 50 mm × 15 mm, and the channel had a depth of 1 mm. The results showed that biphilic surfaces enhanced the performance up to 28% compared to superhydrophilic surfaces at high heat fluxes for subatmospheric boiling. Flow visualization efforts reveal that mixed-wettability surfaces improve heat transfer by extending the efficient slug regime to higher heat fluxes by preventing dried spot formation. These surfaces benefit from high density nucleation sites at low and medium heat fluxes, resulting in a noticeable performance improvement compared to the superhydrophilic surface. The obtained experimental data in this study will be helpful for the development of thermal-fluid systems operating under subatmospheric conditions.

KW - Flow boiling

KW - Heat transfer enhancement

KW - Mixed wettability surface

KW - Sub-atmospheric pressure

KW - Superhydrophilic surface

KW - Superhydrophobic surface

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85171685271&origin=inward&txGid=fb643bfacc5670d10357bebc848f9b77

UR - https://www.mendeley.com/catalogue/8610b6eb-6d03-371f-b8c6-e1ff59ea30f0/

U2 - 10.1016/j.applthermaleng.2023.121476

DO - 10.1016/j.applthermaleng.2023.121476

M3 - Article

VL - 236

JO - Applied Thermal Engineering

JF - Applied Thermal Engineering

SN - 1359-4311

M1 - 121476

ER -