隨著科技進步，電腦自發明以來，不斷地在效能以及尺寸上進行改良，使得高效能、體積小的平板電腦與智慧型手機，越來越融入我們的社會與生活。而體積較大的桌上型電腦，因其處理速度、文件處理能力與軟體應用支援，依舊佔有非常重要的地位。不管是哪一種類型的電腦，散熱一直都是一個相當重要的問題。隨著環保意識抬頭，節約能源與減少有限材料的使用，亦相當受到重視。因此，兼顧散熱優化與環保觀念，便成為重要的研究方向。
本文主要目的在於探討水冷散熱系統中，能否依靠液冷流向以及溫度分佈，找到散熱鰭片的最佳擺放位置。我們測試了五種擺放策略，在三個不同進出口壓差下之散熱效率。我們發現延著最高平均流速之位置擺放散熱鰭片，除可以達到接近最佳擺放之散熱效果外，亦可以在遠少於最佳擺放之模擬次數下，找出應擺放之位置。最佳擺放需進行276次模擬，而最高平均流速策略則只需進行23次模擬，且兩方法之效能差距小於10%。

Due to the great improvement in technology, the performance and the size of computers are enhanced continuously. Making high performance and small volume tablets and smart-phones become more and more involved into our society and daily life. However, the desktops of large volumes are still playing an important role for their high computer speeds, document processing abilities, and application software compatibilities. For all computers and electronics, cooling is always an important issue to be solved. Currently, the environmental protection has been receiving more and more attentions. Consumptions in energy and materials should be minimized. Therefore, it is an important research direction to support the environmental protection with optimized cooling performances.
In this thesis, we studied locations of heat fins in the water cooling system based on the distributions of the velocity and the temperature. Five placing strategies are discussed, and three total pressure drops are used. The results showed that placing heat fins along the highest averaged velocity can provide the cooling performance close to the optimal design. It also requires less simulations than the optimal design. The optimal design needs 276 simulations, while placing heat fins along the highest averaged velocity depends only on 23 simulations. The difference in the cooling performance between these two strategies is less than 10%.

中文證明書 I
英文證明書 II
誌謝 III
摘要IV
Abstract V
Contents VI
Figures VIII
Table XI
Chapter 1 Introduction 1
1.1 Motivation and objective 1
1.2 Literature Review 3
1.3 Summary 7
Chapter 2 Numerical model 8
2.1 Water block geometry 8
2.2 Governing equations, boundary conditions, and averaging settings 11
2.2.1 Governing equations 11
2.2.2 Boundary conditions 12
2.2.3 Averaging settings 13
2.3 Grid size independent test 14
Chapter 3 Simulation Result and Investigation 18
3.1 Strategies I-IV at 10 [Pa] pressure difference 20
3.1.1 Strategy I 20
3.1.2 Strategy II 26
3.1.3 Strategy III 32
3.1.4 Strategy IV 36
3.2 Strategies I-IV at 5 [Pa] pressure difference 43
3.2.1 Strategy I 43
3.2.2 Strategy II 47
3.2.3 Strategy III 53
3.2.4 Strategy IV 56
3.3 Strategies I-IV at 2.5 [Pa] pressure difference 62
3.3.1 Strategy I 62
3.3.2 Strategy II 66
3.3.3 Strategy III 71
3.3.4 Strategy IV 75
3.4 Strategy V at 10 [Pa] pressure difference 81
Chapter 4 Conclusions and future prospects 86
References 89

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[14] www.comsol.com