耦合熱泳與磁場效應下拉伸壁面對熱質傳遞之研究

Effects of Thermophoresis and Magnetic Field on Heat and Mass Transfer for Flow over a Stretching Surface

呂尚宇(Shang-Yu Liu)

指導教授 ： 蔡瑞益

中原大學/工學院/機械工程研究所/碩士(2009年)

https://doi.org/10.6840/cycu200900917

摘要

摘要
本文探討當受到熱泳及磁場效應影響時，混合對流中拉伸表面的
熱質傳遞現象。本文為不可壓縮、穩態和二維層流之平板對稱流的模型，其統御方程式包括動量、能量及濃度場方程式。將統御方程式經過無因次化相似轉換過程後，數值計算方面以Runge-Kutta 積分法配合射擊法求解。結果包含了不同哈特曼數Ha 、艾克數Ec、及理查生數Ri 之流場、溫度場及濃度場分布。

結果可以發現到當磁場效應存在時，哈特曼數會明顯的影響壁面
處的溫度及濃度分佈，這說明了流場內的熱質傳現象會受到磁場效應的影響產生變化，且當艾克數越大時，此現象會更加地明顯。當混合對流參數Ri 增加，流場速度梯度增加，而溫度場以及濃度場的邊界層相對減小。

關鍵字

拉伸壁面 ； 磁場效應 ； 熱泳

並列摘要

ABSTRACT
A study of the effect of thermophoresis and magnetic field on heat and mass transfer by mixed convection from a linearly stretching surface is reported. In this study, the air flow was modeled as two dimensional, incompressible and steady-state laminar flow. The similarity
transformation and numerical technique are used to solve governing equations include mass, momentum, energy and concerntration. The
solutions are obtained by Runge-Kutta integration method and shooting method. The results include velocity profiles, temperature and concentration distributions for different Ha , Ec and Ri .

Results showed that the electromagnetic effects exist the Ha significantly affects the thermal and concentration distributions on the wall surface. The phenomena mention that the electromagnetic effect affect the heat and mass transfer phenomena. The phenomena are more
significant for large Ec . When the mixed convection parameter Ri increases, the velocity gradient increases. Thermal and concentration
boundary layer thickness decrease as Ri increase.

並列關鍵字

magnetic field ； stretching surface ； thermophoresis

參考文獻

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