本文在探討高普朗特數的變黏度流體在兩水平圓球間多孔性介質中之自然對流及熱傳問題。得知孔隙率對於變黏度流體之流場、溫度場及熱傳率的效應皆有明顯的影響。流場隨著雷利數之增加，由原來的單一對流渦漩崩潰而產生不穩定之二級渦漩。黏度與溫度之關係是使用四個參數型式之關係式來模擬，而流體之統御方程式採用B-D-F之非達西效應模式。格點系統方面則使用一組與邊界近乎正交之格線，並且配合權函數法；所用的數值方法係以連續鬆馳法（SOR）解流線方程式，並以交錯直接隱性法（ADI）解渦漩及溫度場。
分析作比較得知流場隨著雷利數(Raleigh Number ,Ra )增加，會增強對流效果而提高熱傳率；隨著普朗特數之增加，浮力效應之增強，熱傳效率也會隨著增加，且隨著孔隙率之增加，其效應越明顯；正偏心為外圓球向上提升其幾合結構可得較佳之熱傳效果，相反地負偏心的幾何結構較不利於自然對流的發展空間，使得熱傳效果較低，且在負偏心之低孔隙率多孔性介質中，在較高之雷利數下，會在內圓球上方產生一逆向之對流；而隨著半徑比之減小，更容易在低雷利數下形成較薄之熱邊界層，在相同之雷利數下，熱傳效果比半徑比大者為佳。

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