Meng[1]等人利用數值模擬以及實驗驗證，研究在自然對流下直板散熱鰭片(straight-fin heat sink, SFHS)之熱性能，研究結果顯示出切角直板散熱鰭片(cut corner straight-fin heat sink, CCSFHS)比起SFHS具有更好的散熱性能。然而由於SFHS和CCSFHS的幾何形狀相似，也有相同的工作條件，基於以上原因對於文獻[1]提出的結論提出疑問:擁有較小傳熱表面積的CCSFHS底板平均溫度是否將會低於較大傳熱表面積的SFHS。因此本論文第一部份將會先對Meng[1]等人研究成果驗證其正確性。
驗證完文獻[1]之準確性後，將使用套裝模擬軟體CFD-ACE+建立模型並搭配拉凡格氏法(Levenberg-Marquardt Method)，設計在固定體積條件下，SFHS之最佳形狀，目標是增加散熱鰭片之散熱效率。在反算問題中將討論三種不同的設計案例。設計A將各鰭片高度作為設計參數，設計B將鰭片位移量作為設計參數，設計C將鰭片高度和鰭片位移作為設計參數。將會探討設計A、B以及C所獲得的最佳形狀對於SFHS底板平均溫度的影響。於本論文最後將會進行實驗驗證，通過對照可顯示出實驗以及數值模擬的最大誤差小於2%，證明了本論文之有效性。與初始SFHS模型相比，設計A與設計C散熱器底板均溫可分別降低4.4%以及9.6%。

The thermal performance of a natural convection straight-fin heat sink (SFHS) was investigated numerically and experimentally by Meng et al. [1]. They concluded that the cut corner straight-fin heat sink (CCSFHS) had better heat dissipation performance than the SFHS. However, with similar geometric structures and identical working conditions of the SFHS and CCSFHS, it is difficult to conclude that the smaller heat transfer surface area of the CCSFHS can result in a lower bottom surface temperature than the larger heat transfer surface area of the SHSF. The first part of this thesis will first verify the correctness of the work by Meng et al. [1].
Then the Levenberg-Marquardt Method (LMM) and CFD-ACE+ will be used to design the optimal shape of SFHS with a fixed fin volume constraint, and the objective is to enhance its heat dissipation. In this study, three different design cases will be considered and discussed. Design A will consider the height of the fins as the design parameters, design B sets the fin displacement as a design parameter and in design C the fin heights and fin displacement are taken as the design parameters. The influence of the optimal shapes obtained from designs A, B and C on the average temperature of the bottom plate of SFHS will be examined. Finally, the experiments will be conducted. Through comparisons, it can be seen that the maximum error between the experiment and the simulation data is less than 2%, which proves the validity of this paper. Compared with the original SFHS, the thermal resistance and average temperature of the bottom plate of design A and design C heat sink can be reduced by 4.4% and 9.6%, respectively.

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