磁場對多孔介質內垂直楔形體混合對流熱與質量 傳遞影響之積分解

Effect of a Magnetic Field on Mixed Convection Heat and Mass Transfer from a Vertical Wedge in a Porous Medium by an Integral Approach

本文應用積分法研究承受橫向磁場充滿導電流體多孔介質內垂直楔形體混合對流熱與質量傳遞。此一內垂直楔形體有一定值之表面溫度與濃度。以積分法所得之簡單近似解與非相似解相當吻合。工程師使用本文所呈現之簡單分析公式，可以很容易求得熱與質量傳遞的重要特性之局部值與平均值。增加楔形角參數會增加局部紐塞爾數與局部希爾吾德數，而增大磁參數則會減少局部紐塞爾數與局部希爾吾德數。邊界層厚度與濃度邊界層厚度之比值隨著磁參數與楔形角參數之增大而減少。

This study uses the integral method to study the heat and mass transfer by combined natural and forced convection from a vertical wedge with constant wall temperature and concentration in porous media saturated with an electrically conducting fluid in the presence of a transverse magnetic field. The simple approximate solutions obtained by the integral method are found to be in reasonable agreement with the nonsimilar solutions. This study presents simple analytic expressions so that any practicing engineer can easily and rapidly calculate the local and average values of important heat and mass transfer characteristics. An increase in the wedge angle parameter tends to increase the local Nusselt number and the local Sherwood number while an increase in the magnetic parameter decreases the local Nusselt number and the local Sherwood number. The ratio of the thermal boundary layer thickness to the concentration boundary layer thickness decreases with the magnetic parameter and the wedge angle parameter.