Integral Solutions for Free Convection Heat and Mass Transfer from Horizontal Cylinders in Porous Media

多孔介質內水平圓柱自然對流熱與質量傳遞之積分解

本文應用積分法研究充滿流體飽和多孔介質內水平圓柱自然對流之熱與質量傳遞。此一水平圓柱有一定值之表面溫度與濃度。以積分法所得之結果與應用相似性分析求得之結果相當吻合。工程師使用本文所呈現之閉合形式積分解，可以很容易求得熱與質量傳遞的特性之局部值與平均值。本文研究熱傳率與質傳率之漸近解，並且找到不同的熱傳率與質傳率之漸近狀態。本文也導出與呈現在不同漸近狀態下之熱傳率與質傳率公式。

This work used an integral method to study the combined heat and mass transfer by free convection from horizontal cylinders embedded in the fluid saturated porous media with constant wall temperature and concentration. The results obtained by the integral method agree well with the solutions calculated by similarity analysis. It is very easy for engineers to use the closed-form integral solution presented in this study for obtaining average and local values of heat and mass transfer characteristics. The asymptotic results for the heat and mass transfer rates were studied and the distinct asymptotic regimes were found for the heat transfer rate and the mass transfer rate. The corresponding heat and mass transfer rate expressions were also derived and presented.