黏性耗散對微管內冪次律流體電滲流熱傳特性之影響

The Effect of Viscous Dissipation on the Electro-osmotic Heat Transfer of Power-Law Fluids in a Microtube

林彥丞(Yan-Cheng Lin)

指導教授 ： 陳建信

國立虎尾科技大學/工程學院/機械設計工程研究所/碩士(2015年)

摘要

近年來微流體裝置廣泛應用於生醫檢測、生化分析等，其所處理的流體種類繁多，如：血液、抗體溶液、高分子溶液、油類溶液等，這些流體並不適合視為牛頓流體作分析，因此微流道內非牛頓流體傳輸現象值得深入研究。微流道中因界面電現象會在壁面附近形成電雙層，此電荷層是呈擴散分佈的。當微流道兩端施加電壓時，流道中溶液會因電雙層而產生整體的流動現象，此即為電滲流。
在現有文獻中關於圓形微流道(或稱微管)中非牛頓流體熱傳的相關研究非常少，因此，本文主要目的在於探討微管冪次律流體受到壓力梯度與外加電場作用下之流動與熱傳特性，並詳細探討黏性耗散對微管流熱能傳輸之影響。藉由求解電位場、動量及能量方程式得到電雙層中之電位分佈、流體速度、溫度分佈、摩擦係數及紐賽爾數等，以便明瞭冪次律流體微管流之熱傳特性。

關鍵字

微管 ； 電滲流 ； 冪次律流體 ； 黏性耗散 ； 紐賽爾數

並列摘要

In recent years, microfluidic devices are widely used in biochemical detection and biochemical analysis. Common types of fluids handled in microfluidic devices include whole blood samples, antibody solutions, oils, etc. It’s not suitable regarded as Newtonian fluid for analysis, therefore the transport characteristics of non-Newtonian fluid in a microchannel is worthy of further investigation. The rearrangement of the charges on the solid surface and the balancing charges in the liquid will cause the so-called electrical double layer (EDL). Electro-osmotic flow is the flow induced by the application of electric field across the channel and due to the presence of EDL close to the channel wall.
In the existing literature concerning electro-osmotic thermal flow in a circular microchannel (microtubule), study of heat transfer related to power-law fluids is very scanty; therefore, the main purpose of the present work is to explore the heat transfer characteristics of power-law fluids under the combined effects of pressure gradient and the applied electric field, putting emphasis on the impact of viscous dissipation. The governing system of equations includes the electrical potential field, momentum equation, and energy equations. The solutions for flow and heat transfer parameters are obtained by numerical integrations of the analytical expressions.

並列關鍵字

Microchannel ； electroosmotic flow ； Power-Law fluids ； Viscous dissipation ； Nusselt number

參考文獻

[1] D. Maynes, B.W. Webb, ” Fully Developed Electro-Osmotic Heat Transfer in Microchannels”, Int. J. Heat Mass Transfer, 46, 1359-1369, (2003).

[2] D. Maynes, B.W. Webb, ”Fully-Developed Thermal Transport in Combined Pressure and Electro-Osmotically Driven Flow in Microchannels”, ASME J. Heat Transfer, 125, 889-895, (2003).

[3] D. Maynes, B.W. Webb, ” The Effect of Viscous Dissipation in Thermally Fully-Developed Electro-Osmotic Heat Transfer in Microchannels”, Int. J. Heat Mass Transfer, 47, 987-999, (2004).

[4] C. Zhao, E. Zholkovskij , J.H. Masliyah , C. Yang, ” Analysis of Electroosmotic Flow of Power-Law Fluids in a Slit Microchannel”, J. Colloid Interface Sci., 326, 503-510, (2008) .

[5] G.H. Tang, X.F. Li, Y.L. He , W.Q. Tao , ” Electroosmotic Flow of Non-Newtonian Fluid in Microchannels”, J. Non-Newtonian Fluid Mech.157, 133-137 , (2009).