碩士 / 國立清華大學 / 動力機械工程學系 / 103 / In this study, the effects of chassis perforation on the natural convection from a horizontal rectangular-fin heat sink have been studied numerically. The parameters include perforation pattern, local and overall opening ratio, and the thermal conductivity of the chassis material. In the first part, single-channel analysis is conducted for various perforation patterns. The results show that when the upper chassis wall is perforated over the middle region of the heat sink, with a single perforation or multiple dispersed perforations, the venting flow can be smooth and fast, yielding effective cooling of the heat sink. In the second part, the computation domain includes a half of the system. The effect of the heat transfer associated with the printed circuit board is found to slightly enhance the natural convection from the heat sink when the system is in the horizontal orientation. But stronger enhancement is displayed in the vertical orientation. When plastic is selected as the chassis material, the total heat flux of the heat sink within it is 20% higher than that of the aluminum alloy chassis in horizontal orientation. The total heat fluxes of the heat sink in a horizontal system are significantly lower than those in a vertical system. For example, the ratio of the total heat flux between two different orientations is 0.73 in a plastic chassis, but it decreases to 0.61 in an aluminum alloy chassis.
| Identifer | oai:union.ndltd.org:TW/103NTHU5311068 |
| Date | January 2015 |
| Creators | Chou, I Wen, 周怡文 |
| Contributors | Wong, Shwin-Chung, 王訓忠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 60 |
Page generated in 0.0015 seconds