沿垂直面生物磁性流體之邊界層熱傳研究

Study on Boundary-Layer Heat Transfer of Bio-magnetic Fluid along a Vertical Surface

吳政特(Cheng-Te Wu)

指導教授 ： 陳建信

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2012年)

https://doi.org/10.6827/NFU.2012.00049

摘要

本文分析在與板面平行的一承載電流之導線所產生的磁場作用下，沿垂直面生物磁性流體之流動行為，使用有限差分法求得數值解，探討重要參數對熱流場特性之影響。在不同磁通量密度情況下，求得邊界層內的速度分佈、溫度分佈，並計算局部摩擦係數與紐賽爾數之值，探討磁通量密度對其之影響。另外改變承載電流之導線位置，探討導線位置對上述參數之影響。
從研究結果可得知，在磁通量密度的作用下，在各流向位置之速度分佈皆會增加，並隨磁通量密度增加，而有更明顯的增加；在各流向位置之溫度分佈則會降低，同樣隨磁通量密度增加，而有更明顯降低。局部摩擦係數與紐賽爾數在磁通量密度作用下皆有所增加，並隨磁通量密度增加而有著更明顯的增加。導線位置的移動，也對上述的四個參數有所影響，導線在 、 軸位置的移動皆使局部摩擦係數與紐賽爾數有著明顯的增減，且各點位置所得之速度分佈與溫度分佈也有明顯的差異。

關鍵字

生物磁性流體 ； 磁通量密度 ； 邊界層 ； 鐵磁流體力學 ； 磁液動理論

並列摘要

In this paper we analyze the flow of bio-magnetic fluid along a vertical surface under the influence of a localized magnetic field, which is generated by an electric current going through a wire placed parallel to the plate. Numerical solutions are generated by the finite difference method to explore the influence of important parameters on the flow and heat transfer characteristics. The velocity and temperature profiles in the boundary layer for various values of magnetic induction are obtained. Also, the local friction coefficient and local Nusselt number are calculated. The influence of magnetic induction on the transport parameters are examined. Moreover, the impacts of change of the wire location on the flow and heat transfer are investigated.
The results show that the velocity profiles are increased due to the influence of magnetic induction. When magnetic induction increases, the velocity profiles increase more apparently. The temperature profiles are decreased due to the influence of magnetic induction. When mangetic induction increases, the temperature profiles decrease more obiviosly. The local friction coefficient and local Nusselt number are affected by the magnetic induction in a similar way as that for the velocity profile. In addition, the change in the wire location has significant influence on the local friction coefficient, local Nusselt number, velocity and temperature profiles.

並列關鍵字

Biomagnetic fluid ； Magnetic induction ； Boundary layer flow ； Ferrohydrodynamics ； Magneto hydrodynamics

參考文獻

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