碩士 / 國立海洋大學 / 機械與輪機工程學系 / 90 / The heat and temperature generated inside a high performance CPU have been increased dramatically in recent years due to the demands in CPU speed. A combination of fin array and motor fan is the most common engineering practice in CPU’s heat dissipation for current desk top and lap top PC computers. It is the objective of this thesis to study the effects of fins configurations and dimensions to its heat transfer rate. The analysis and models developed in the thesis can be applied to the thermal design and analysis of the fin arrays used in the CPU of desk top computers .
The well known commercial code “ANSYS” is used in the simulations of the fin array thermal models. The objective of this study is to minimize its fin sizes and weights so that a more compact fin array design can be achieved. The investigations are divided into five parts as following : 1. Fin thickness effect 2. Convection coefficient effects 3. Fin array spacing effect and its relation with thickness 4. Fin shape effect 5. A practical case study.
It is found that both the thickness and spacing have strong effects in fin array overall efficiency. A ratio of 1.5 to 1.6 between base thickness and spacing is the “golden ratio” for 3 different fin shapes studied. The base thickness can be increased to obtain higher fin efficiency and more compact size fin array if the original overall efficiency is below 0.8.
The thickness, spacing and fin shape effects stated above are irrelevant to the fin materials used (aluminum or copper alloy). However, the material with higher conductivity such as copper alloy can increase total heat transfer rate.
The estimation of convection heat transfer coefficient, which is one of the most critical values in the design of fin array, is studied. Further detail flow analysis in the vicinity of the fin array can help in more precise design analysis of the fin arrays used in the cooling of high performance CPU.
| Identifer | oai:union.ndltd.org:TW/090NTOU0491011 |
| Date | January 2002 |
| Creators | 張志崴 |
| Contributors | , 雷顯宇, 楊國誠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 72 |
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