Anisotropic wicking surfaces have attracted the attention of numerous research groups in recent years. Wicking characteristics can be improved by generating unidirectional flow behavior within surfaces composed of micropillars that are bent in the direction of interest. In the present work, we created surfaces composed of bent polymerized pillar arrays with center-to-center spacings of 250 and 500 µm and experimentally investigated boiling heat transfer under subcooled flow conditions (40 K). The test surfaces were chemically coated with a 200-nm-thick hydrophilic layer to evaluate the effects thereof on subcooled flow boiling. Surface anisotropy and the center-to center spacings between neighboring pillars significantly improved surface wickability and boiling heat transfer, compared to surfaces with vertically polymerized pillars. Enhancements of the critical heat flux (17–34%) and the heat transfer coefficient (8–71%) were evident on polymerized pillar surfaces compared to bare polymerized surfaces. The experimental results were validated by theoretically analyzing the relationship between the liquid pinning forces and the polymerized pillar surfaces' configurations to understand better how boiling heat transfer was enhanced on anisotropic wicking surfaces during subcooled flow boiling.
|Journal||International Journal of Heat and Mass Transfer|
|Publication status||Published - 2022 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.
© 2021 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes