微流道中二相分層流的數值模擬

Simulation of two-phase stratified flow in micro-channel

孫偉豪(Wei-Hao Sun)

指導教授 ： 李雨

國立臺灣大學/工學院/應用力學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.01915

摘要

摘 要

本文利用FLOW-3D®軟體，對微流道中二相分層流的流場作數值模擬。在植入式微型生醫晶片中，我們能須由微流道釋出少量的校正液，以作在生物探針校正用，而為引發本文之研究動機。本文中我們將就兩相關的流力、擴散、界面張力及電場等效應進行模擬分析，以了解相關物理，及提供實驗設計者作設計之參考。
經模擬分析後，在純流力的條件下，我們可以判斷出由噴流入設的流體塗佈的優劣，主要主導因素為主流道的流量，主流道流量愈大時，可得到較好的結果；若加入擴散效應後，流場存在有質傳的效應，但在有主流道流量推動下佈結果與純流力相差不大，但在關閉驅動源後，流體的濃度會持續擴散達穩態。對於兩不相溶液體，噴流入射的液體會因界面張力效應形成周期性液滴，流場情況與無界面張力者有很大的差異。最後，我們以電極直接驅動離子溶液，由結果顯示必須要在高電壓下，才能達到明顯的驅動流體， 因此設計對於植入式生醫晶片而言，可能並不適合。

關鍵字

微流力 ； 二相分層流 ； 噴流 ； 擴散 ； 界面張力 ； 電泳

並列摘要

Abstract
We use the FLOW-3D® software to do the reseach about the simulation of two-phase stratified flow in micro-channel. The research motive is that how can we use the littlest injection fluid releasing from the liquid tank to calibrate the biological probe in the biological chip. We will simulate different models which contain fluid mechanics, diffusion, interfacial tension and electric effect in the micro-channel and we also provide some conclusions and suggestions for the future experiments.
After analyzing the cases, we find out that the the coating results are controled by the volume flow rate of the mainstream in fluid mechanics aspect. However, we add the diffusion effect; the results seem the same as the results in the fluid mechanics aspect. If the two fluids are immiscible, the interfacial tension effect should be considered and the results are quite different. At last, we try to use the electric potential to drive the ionic solution, but it could not suit for our biological chip because it works at the very high electric potential.

並列關鍵字

microfluidic ； two-phase stratified flow ； jet in cross flow ； diffusion ； interfacial tension ； electrophesis

參考文獻

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Gardon, R. & Akfirat, J.C. 1966 Heat transfer characteristics of impinging two-dimensional air jets. J. Heat Trans. 88, 101-108

Glauert, M. B. 1956 The Wall Jet. J. Fluid Mech. 1(6), 625-643

Hahn, S. & Choi, H. 1997 Unsteady Simulation of Jets in a Cross Flow. J. Computational Phys. 134, 342-356