This study experimentally investigated the influence of heterogeneous wettability-patterned surfaces with varying inter-spacing on flow boiling heat transfer characteristics. The test surfaces consisted of three fluorooctyltrichlorosilane hydrophobic-patterned array structures having a triangle, inverted triangle, and circular shape on a SiO2- hydrophilic substrate, with an inter-spacing of 0.75 or 1 mm. The working fluid was deionized water, and the Reynolds number was 6,000 at atmospheric pressure. Among the test surfaces, varying the inter-spacing between neighboring hydrophobic patterns slightly enhanced the heat transfer coefficient (HTC) due to changing the bubble characteristics. In terms of the shape effect of hydrophobic patterns, the heterogeneous wettability-patterned surfaces dominated the overall flow boiling heat transfer performance showing a significant increase in critical heat flux (CHF) compared to the Si surface, by 40–43%. In addition, all of the wettability test surfaces showed a markedly higher heat transfer coefficient than the Si surface, by 35–163%. This experiment is explained by analyzing the relationship between bubble lift forces and the various hydrophobic-patterned shapes in a horizontal flow channel, in an attempt to better understand flow boiling heat transfer and optimize the pattern design.
|Journal||International Journal of Heat and Mass Transfer|
|Publication status||Published - 2021 Jan|
Bibliographical noteFunding Information:
This work was supported by the Human Resources Development program (No. 20204030200110 ) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes