碩士 / 國立成功大學 / 機械工程學系碩博士班 / 98 / Numerical analyses were carried out to study the 3-D heat transfer and flow in the rectangular finned-tube heat exchangers with inclined block shape vortex generators mounted behind the tubes. The study was performed for a variety of span angle over a range of flow conditions. In addition, numerical simulation was performed by a 3-D turbulence analysis of the heat transfer and fluid flow. There were four model types for this research, including VG0 to VG3. VG0 was the initial type which without vortex generators, and VG1 to VG3 represented the span angle 30°, 45° and 60°. The numerical result indicated these effects were intensified as the span angle is increased. Furthermore, no matter the arrangement type (in-lined and staggered), the case of 60° span angle provided the best heat transfer and Colburn factor augmentation, of course, the pressure drop and friction factor higher than the other, In Colburn factor, the 60° span angle case (VG3) is higher than without vortex generator 53.1% at in-line, staggered is higher 56.8%; In friction factor, the 60° span angle case (VG3) is higher than without vortex generator 48.6% at in-line, staggered is higher 53.3%. A reduction in fin area of 26.8% may be obtained if vortex generators embedded fins are used at in-lined arrangement rectangular finned-tube heat exchangers, and staggered arrangement reduction in fin area is 29.3% ~25.1%
| Identifer | oai:union.ndltd.org:TW/098NCKU5490017 |
| Date | January 2010 |
| Creators | Da-SingLi, 李大興 |
| Contributors | Jiin-Yuh Jang, 張錦裕 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 81 |
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