碩士 / 國立雲林科技大學 / 機械工程系碩士班 / 95 / ABSTRACT
This study conducts an experimental study to examine the frictional and heat transfer performance for several pin fins with different shape and heat transfer area. The flow conditions are turbulent and confined flow. The tested pin fins include elliptic pin fin, droplet pin fin, square pin fin, airfoil pin fin and circular pin fin. The test results are divided into friction loss and heat transfer for analysis. (1) The heat transfer coefficients for different pin fins are investigated with the variation of the front air velocity. The resulted heat transfer coefficient and thermal resistance are related to the air velocity or Reynolds number. The heat transfer coefficient is increased with the air velocity, while the thermal resistance is decreased with the increase of air velocity. （2）The friction loss or pressure drop for different pin fins is also studied. The resulted pressure drop is discussed with the variation of the friction factor , front air velocity and Reynolds number . The tested results also indicate that the heat transfer performance for pin fins in staggered array is better than the aligned array. However, the pressure drop for the staggered flow is higher due to the induced wake flow at the back face of the pins. From the view of fin geometry, the square pin fin has the best heat transfer coefficient, and the second is the circular pin fin, then the droplet pin fin. For the friction loss, airfoil pin fin has the smallest pressure drop since it has the smooth flow line in the shape; the next is the elliptic pin fin, and then the square pin fin. For the comparison between the performance of plate fin and pin fin, the pin fin has higher heat transfer coefficient and smaller friction loss. However, plate fin has greater heat transfer area, thus, its total heat transfer rate may be higher than that of pin fin.
| Identifer | oai:union.ndltd.org:TW/095YUNT5489006 |
| Date | January 2007 |
| Creators | Yang-Cheng Da, 楊承達 |
| Contributors | none, 陳英洋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 88 |
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