DC Field | Value | Language |
---|---|---|
dc.contributor.author | Jun, Soohwan | ko |
dc.contributor.author | Kim, Sung Jin | ko |
dc.date.accessioned | 2019-06-17T08:30:05Z | - |
dc.date.available | 2019-06-17T08:30:05Z | - |
dc.date.created | 2019-06-13 | - |
dc.date.created | 2019-06-13 | - |
dc.date.issued | 2019-07 | - |
dc.identifier.citation | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, v.137, pp.1064 - 1075 | - |
dc.identifier.issn | 0017-9310 | - |
dc.identifier.uri | http://hdl.handle.net/10203/262647 | - |
dc.description.abstract | In this study, a criterion for normal operation of micro pulsating heat pipes (MPHPs) even in a horizontal orientation is developed through experimental and theoretical investigations. Using MEMS techniques, a ten-turn closed-loop MPHP with overall dimensions of 50 x 33.5 x 1.7 mm(3) is fabricated. The rectangular micro-channels engraved on a silicon wafer have a width of 1 mm and a depth of 0.5 mm. Ethanol is used as the working fluid and the filling ratio is 47% on the average. To allow flow visualization, a glass wafer is bonded to the silicon wafer. The temporal variations in the temperature and pressure of two neighboring vapor plugs in the MPHP are measured using micro-thermocouples and pressure transducers. The flow behavior in the MPHP is recorded using a high-speed camera and fully synchronized in real time with the measured temperature and pressure data. To find a criterion for normal operation of PHPs, the MPHP is treated as a mass-spring-damper system, and it is postulated that the transition from (to) a stopover to (from) a large-amplitude oscillation in the MPHP occurs with negative (positive) damping. This postulate is experimentally confirmed with the MPHP operating in a horizontal orientation. Finally, a figure of merit for normal operation of PHPs is proposed. The ratio of the minimum thermal resistance in a vertical orientation to that in a horizontal orientation (R-th,R- V,R- min/R-th,R- H,R- min) is proportional to (D-h/L-eff)(2), the square of the ratio of the hydraulic diameter to the effective length of PHPs. For PHPs filled with ethanol, it is experimentally confirmed that D-h/L-eff has to be greater than approximately 0.03 for normal operation without any stopovers in a horizontal orientation. (C) 2019 Elsevier Ltd. All rights reserved. | - |
dc.language | English | - |
dc.publisher | PERGAMON-ELSEVIER SCIENCE LTD | - |
dc.title | Experimental study on a criterion for normal operation of pulsating heat pipes in a horizontal orientation | - |
dc.type | Article | - |
dc.identifier.wosid | 000469154600088 | - |
dc.identifier.scopusid | 2-s2.0-85063950290 | - |
dc.type.rims | ART | - |
dc.citation.volume | 137 | - |
dc.citation.beginningpage | 1064 | - |
dc.citation.endingpage | 1075 | - |
dc.citation.publicationname | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER | - |
dc.identifier.doi | 10.1016/j.ijheatmasstransfer.2019.03.163 | - |
dc.contributor.localauthor | Kim, Sung Jin | - |
dc.description.isOpenAccess | N | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordPlus | CLOSED-LOOP | - |
dc.subject.keywordPlus | PERFORMANCE | - |
dc.subject.keywordPlus | FLOW | - |
dc.subject.keywordPlus | FABRICATION | - |
dc.subject.keywordPlus | DESIGN | - |
dc.subject.keywordPlus | TURNS | - |
dc.subject.keywordPlus | LIMIT | - |
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