電泳效應影響非達西多孔性介質中熱質傳遞之研究

Effects of Electrophoresis on Heat and Mass Transfer in a Non-Darcian Porous Medium

謝宇書(Yu-Shu Xie)

指導教授 ： 蔡瑞益

中原大學/工學院/機械工程學系/碩士(2006年)

https://doi.org/10.6840/CYCU.2006.00394

摘要

摘要
本文探討當受到電泳效應影響時，線熱源壁煙流在非達西多孔性介質中的自然對流熱質傳遞現象。達西定律說明了當低流速流體經過多孔性介質時，流體的平均流速與摩擦阻力造成的壓力降成正比關係，但是當流速太大或以平均孔隙直徑為基準的雷諾數大於1的情況下，達西定律就不再適用，此時必須考慮加入慣性效應、邊界效應等非達西效應。本文將針對電場的存在造成電泳效應產生的影響做一詳細分析。
統御方程式包括連續方程式、動量方程式、能量方程式及濃度場方程式，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積分法與射擊法求解。結果包含了不同Le數、浮力比N、位置參數ξ的速度、溫度及濃度分布，並與加入電泳效應的情況來作比較。
結果可以發現到當電場存在時，電泳效應會明顯的影響壁面處的濃度分布，這說明了流場內的微粒會受到電泳效應的影響而推離或吸附於壁面，且當浮力比 及 數越大時，此現象會更加地明顯。

關鍵字

電泳 ； 煙流 ； 非達西

並列摘要

ABSTRACT
A study of the effect of electrophoresis on heat and mass transfer by natural convection from the line source embedded in a non-Darcian porous medium is reported. Darcy’s law proves that when flow through a porous medium the pressure drop caused by the frictional drag is proportional to velocity for low speed flow. At high flow velocity or the Reynolds number based on the mean pore diameter exceeds 1, Daycy’s law is no longer suitable. Non-Darcian effects which include the inertial and boundary effects will be considered.
The governing equations include the continuity, momentum, energy and concentration equations. The solution methods are used similar transformation and dimensionless technique for the governing equations. In numerical analysis, the equations are solved by the Runge-Kutta integration and shooting method. The results include velocity profiles, temperature and concentration distributions for different , , and then make comparisons with the situation of adding the electrophoresis effect.
The results showed that the electrophoresis effect will make particles deposit on the wall and increase the concentration distribution near the wall . It is more significant for large and number.

並列關鍵字

electrophoresis ； Non-Darcian ； plumes

參考文獻

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