本文以逆算法與CFD軟體配合實驗數據探討矩形鰭片置於各種不同矩形外殼內之熱傳及流體流動特性，並探討鰭片間距、外殼大小與風速對結果之影響。由於鰭片上的熱傳係數並非均勻分佈，故將鰭片表面分割成數個子區域並假設各子區域之熱傳係數為常數，再利用結合有限差分法、最小平方法及實驗溫度量測值之逆算法來預測鰭片上的熱傳係數；本文亦利用CFD軟體求得於外殼內之空氣溫度與速度分佈以及鰭片表面之溫度與熱傳係數，為了求出本研究較正確之熱傳及流體流動特性，選用適當的流動模式及網格格點數所求得之鰭片熱傳係數，須盡可能分別接近實驗溫度量測值、逆算結果及先前之結果。結果顯示，流動模式對結果之影響不容忽視，於封閉殼內鰭片上的自然對流平均熱傳係數會隨鰭片間距、外殼長度的增加而增大，且開孔後的外殼高度可有效提升煙囪效應的效果；而封閉殼內鰭片上的混合對流平均熱傳係數則隨外殼長度的縮小而降低，若小於某長度後，加裝風扇的散熱效果則不比外殼開孔下之自然對流為佳，此外，風扇的作用亦使得外殼高度的影響變小。為了驗證本文逆算法預測結果之可靠度，亦與其它相關文獻之經驗公式以及CFD軟體之模擬進行比較。

This study applies inverse method and FLUENT to determine the heat transfer and fluid flow characteristics of plate-fin heat sinks with various enclosures and whether to install the axial-flow fan inside. Using measured data to forecast and analyze the average heat transfer coefficient on the fin in limited space. The inverse method along with the finite difference method and experimental temperature data is applied to determine the heat transfer coefficient. Since the distribution of the heat transfer coefficient on the fin is not uniform, the plate-fin is divided into several sub-fin regions and the heat transfer coefficient in each sub-fin region is assumed to be unknown constant. The results indicate that the heat transfer coefficient increase with increasing fin spacings and lengths of the enclosure in natural convection. Increasing the heights of enclosure can effectively enhance the stack effect after using some openings. But the average heat transfer coefficient decreases with decreasing length of the enclosure in mixed convection. If the length of the enclosure less than a given value, the heat dissipation of fins with axial-flow fan in mixed convection is worse than which inside of the enclosure with openings in natural convection. At the same time, the effect of the height of the enclosure decreases when using axial-flow fan. In order to verify the reliability of the inverse method with predicted results of this paper, the present study also in comparison with the empirical corelations of other relevant literature and CFD simulation packages.

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