碩士 / 中原大學 / 機械工程研究所 / 100 / When the LED lamp is not in a completely closed environment the flow field in the lamp will not show complete natural convection but show mixed convection or forced convection which is divided by inlet fluid velocity, when LED heat sink fin’s arrangement is perpendicular to the direction of inlet fluid it may causes some thermal problems like non-uniform temperature distribution or hot point. To avoid those thermal problems the perforate fin had been investigated by numerical analysis.
The perforate fin will provide much better performance of fluid through the heat sink, furthermore it also provide not only increase the heat transfer area but also restrain the developing of thermal boundary layers at the same time. Simulation results show that perforate fin have better performance because of its lager heat transfer area. In order to chose the best environment for perforate geometry, the relation to the fluid velocity、heat source form、heat source temperature and heat sink material had been investigated respectively. Results show that the heat transfer performance is proportional to velocity, but the relation to the temperature gradient of heat source is influenced by other factors, the matrix heat source with large area has smallest temperature gradient when velocity increase, and high temperature point heat source under perforate form has best efficiency when velocity increase. Furthermore, it’s a good ideal to choose ceramic material because its high emissivity, it is appropriate material for perforate heat sink due to the larger heat transfer area of perforate type.
| Identifer | oai:union.ndltd.org:TW/100CYCU5489026 |
| Date | January 2012 |
| Creators | Qing-Wen Zeng, 曾慶文 |
| Contributors | Ruey-Yih Tsai, 蔡瑞益 |
| 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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