Enhanced pool boiling critical heat flux induced by capillary wicking effect of a Cr-sputtered superhydrophilic surfaces
- Title
- Enhanced pool boiling critical heat flux induced by capillary wicking effect of a Cr-sputtered superhydrophilic surfaces
- Author
- 김성중
- Issue Date
- 2016-10
- Publisher
- Korean Nuclear Society
- Citation
- Transactions of the Korean Nuclear Society Autumn Meeting Gyeongju, Korea, October 27-28, 2016, Page. 1-4
- Abstract
- In light of boiling heat transfer, the smooth surface potentially reduces active nucleation of bubbles and rewetting of dry spots near the critical heat flux (CHF). This kind of process is highly likely to deteriorate the CHF. Thus, it is essential to produce appropriate microstructures on the surface for the enhancement of the CHF. In this study, to investigate the microstructural effect of thin film-fabricated surfaces on the pool boiling CHF, we controlled the surface roughness in a narrow range of 0.1-0.25 μm and its morphologies, in the form of micro-scratches using PVD sputtering technique. Specifically for DC magnetron sputtering, pure chromium (Cr) was selected as a target material owing to its high oxidation resistance. In order to analyze the CHF trend with changes in roughness, we introduced existing capillary wicking-based models because superhydrophilic characteristics of microstructures are highly related to the capillary wicking behaviors in micro-flow channels. After Cr sputtering under given conditions, the Cr-sputtered surfaces showed superhydrophilic characteristics and its capability became more enhanced with an increase of surface roughness. Judging from spreading behavior of a liquid droplet, the presence of micro-wicking channels, coupled with Cr nanostructures, effectively enhanced the advancing rate of drop base diameter. The CHF exhibited an increasing trend with increasing surface roughness. However, the enhancement ratio agreed poorly with the predictions of the roughness factor-based models, all of which originated from a conventional static force balance
- URI
- https://www.kns.org/files/pre_paper/36/16A-149%EC%86%90%ED%99%8D%ED%98%84.pdfhttps://repository.hanyang.ac.kr/handle/20.500.11754/81142
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- COLLEGE OF ENGINEERING[S](공과대학) > NUCLEAR ENGINEERING(원자력공학과) > Articles
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