進出口的夾角設計對無閥式微幫浦效能影響之數值模擬

Numerical Simulations on the Effect of the Angle between the Inlet and the Outlet of a Valveless Micropump

陳柏維(Bo-Wei Chen)

指導教授 ： 張正憲

國立臺灣大學/工學院/應用力學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.00746

摘要

本文利用商業軟體ANSYS作為數值模擬的工具，對噴嘴/擴散器式的壓電無閥式微幫浦作數值模擬分析，藉由改變進、出口噴嘴/擴散器的夾角變化，探討其對微幫浦性能的影響。除了比對實驗的流量之外，同時將模擬計算出的流場與實驗上的流場顯影作比較與討論，並分析流場中的渦旋的位置與漩度，討論渦漩對於流量的影響。
與一般常用的模擬微幫浦之方法不同，本文的模型沒有經過簡化，而是考慮壓電材料與微幫浦之間的電、流、固多重耦合分析。本文處理流固耦合所使用的模擬計算方法也有別於一般CFD軟體的移動邊界(moving boundary)，而是透過ANSYS與ANSYS CFX將結構場與流場結合的同步雙向耦合，比起一般的移動邊界法，本文所得到的流場更為擬真且可信。
由數值計算結果可以發現，進、出口噴嘴/擴散器的夾角為52.5°時有最佳的流量，經由流場的觀察與分析，其原因是因為進出口端噴嘴/擴散器靠近，使得進出口端的接觸較早，相互作用較為劇烈，使得流體由進口端流入後就會被帶往出口端，相較於進、出口噴嘴/擴散器的夾角為180°時，流體由進口端流到出口端相對容易，距離較短，且速度較快。

關鍵字

無閥式微幫浦 ； 噴嘴/擴散器 ； 旋轉角

並列摘要

This paper used ANSYS software to analyzes efficiency of valveless nozzle/diffuser-based micropump by changing the angle of inlet and outlet. This paper not only compared the flow rate with experiment, but also discussed and analyzed the property of fluid field, including vortex position and vorticity in the chamber of micropump.
Unlike the general method in the simulation of micropump, the simulating model in this study is built to be more complete. Not only piezoelectric materials, the structure of micropump, and the flow field are considered here. Also, the braking method is much different from the traditional one. Instead of moving boundary method, the interaction of the electric field, flow field and the structure is considered in this paper. Besides, the simulation results are much better and believable.
According to the result of the simulations, we found that when close the angle of inlet and outlet to 52.5o, the flow rate was the best, because the outlet vortex and the inlet vortex approach earlier than other cases, and it causes the stronger interaction, when the fluid comes into chamber from inlet, it will be lead to the outlet soon, compare with other cases, the velocity of fluid is fast, and the distance of the path is short.

並列關鍵字

Valveless Micropump ； nozzle/diffuser

參考文獻

18. 　謝明哲, 無閥式微幫浦之腔體設計與作動機制研究. 國立台灣大學應用力學研究所碩士論文, 2009.

19. 　蔡文惠, 進出口設計對無閥式微幫浦效能影響之實驗探討. 國立台灣大學應用力學研究所碩士論文, 2010.

31. 　林家祥, 進出口設計對無閥式微幫浦效能影響之數值模擬. 國立台灣大學應用力學研究所碩士論文, 2011.

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