Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water
In recent film boiling heat transfer studies with nanofluids, it was reported that deposition of nanoparticles on a surface significantly increases the nominal minimum heat flux (MHF) or Leidenfrost Point (LFP) temperature, considerably accelerating the transient cooling of overheated objects. It wa...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | en_US |
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Japan Society of Mechanical Engineers, The
2014
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| Online Access: | http://hdl.handle.net/1721.1/84051 |
| _version_ | 1826195465198108672 |
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| author | Hu, Lin-Wen Buongiorno, Jacopo Kim, Hyungdae Truong, Bao H. |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Hu, Lin-Wen Buongiorno, Jacopo Kim, Hyungdae Truong, Bao H. |
| author_sort | Hu, Lin-Wen |
| collection | MIT |
| description | In recent film boiling heat transfer studies with nanofluids, it was reported that deposition of nanoparticles on a surface significantly increases the nominal minimum heat flux (MHF) or Leidenfrost Point (LFP) temperature, considerably accelerating the transient cooling of overheated objects. It was suggested that the thin nanoparticle deposition layer and the resulting changes in the physico-chemical characteristics of the hot surface, such as surface roughness height, wettability and porosity, could greatly affect quenching phenomena. In this study, a set of water-droplet LFP tests are conducted using custom-fabricated surfaces which systemically separate the effects of surface roughness height (0-15 um), wettability (0-83°) and nanoporosity (∼23 nm). In addition, high-speed imaging of the evaporating droplets is used to explore the influence of these surface characteristics on the intermittent solid-liquid contacts in film boiling. The obtained results reveal that nanoporosity (not solely high surface wettability) is the crucial feature in efficiently increasing the LFP temperature by initiating heterogeneous nucleation of bubbles during short-lived solid-liquid contacts, which results in disruption of the vapor film, and that micro-posts on the surface intensify such effects by promoting intermittent liquid-surface contacts. |
| first_indexed | 2024-09-23T10:13:05Z |
| format | Article |
| id | mit-1721.1/84051 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:13:05Z |
| publishDate | 2014 |
| publisher | Japan Society of Mechanical Engineers, The |
| record_format | dspace |
| spelling | mit-1721.1/840512023-02-26T02:06:24Z Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water Hu, Lin-Wen Buongiorno, Jacopo Kim, Hyungdae Truong, Bao H. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering MIT Nuclear Reactor Laboratory Buongiorno Jacopo Hu, Lin-Wen Buongiorno, Jacopo Kim, Hyungdae Truong, Bao In recent film boiling heat transfer studies with nanofluids, it was reported that deposition of nanoparticles on a surface significantly increases the nominal minimum heat flux (MHF) or Leidenfrost Point (LFP) temperature, considerably accelerating the transient cooling of overheated objects. It was suggested that the thin nanoparticle deposition layer and the resulting changes in the physico-chemical characteristics of the hot surface, such as surface roughness height, wettability and porosity, could greatly affect quenching phenomena. In this study, a set of water-droplet LFP tests are conducted using custom-fabricated surfaces which systemically separate the effects of surface roughness height (0-15 um), wettability (0-83°) and nanoporosity (∼23 nm). In addition, high-speed imaging of the evaporating droplets is used to explore the influence of these surface characteristics on the intermittent solid-liquid contacts in film boiling. The obtained results reveal that nanoporosity (not solely high surface wettability) is the crucial feature in efficiently increasing the LFP temperature by initiating heterogeneous nucleation of bubbles during short-lived solid-liquid contacts, which results in disruption of the vapor film, and that micro-posts on the surface intensify such effects by promoting intermittent liquid-surface contacts. United States. Dept. of Energy. Office of Nuclear Energy (NEUP Fellowship Program) 2014-01-17T13:23:57Z 2014-01-17T13:23:57Z 2012-07 2012-01 Article http://purl.org/eprint/type/JournalArticle 1880-5566 http://hdl.handle.net/1721.1/84051 Kim, Hyungdae et al. “Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water.” Journal of Thermal Science and Technology 7.3 (2012): 453–462. en_US http://dx.doi.org/10.1299/jtst.7.453 Journal of Thermal Science and Technology Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Japan Society of Mechanical Engineers, The Prof. Buongiorno via Chris Sherratt |
| spellingShingle | Hu, Lin-Wen Buongiorno, Jacopo Kim, Hyungdae Truong, Bao H. Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title | Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title_full | Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title_fullStr | Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title_full_unstemmed | Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title_short | Effects of Micro/Nano-Scale Surface Characteristics on the Leidenfrost Point Temperature of Water |
| title_sort | effects of micro nano scale surface characteristics on the leidenfrost point temperature of water |
| url | http://hdl.handle.net/1721.1/84051 |
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