Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2668
標題: 微混合器及微流體開關之設計與探討
Designs of Micro-mixer and Micro-fluidic Switch
作者: 蔡順興
Hsing, Tsai Shun
關鍵字: micromixer;微混合器;microswitch;CFD;microchannel;微流體開關;計算流體力學;微流道
出版社: 機械工程學系
摘要: 
本研究之總體目標為發展被動式之微流體快速混合裝置與微流體開關與計量之流道。採用之方法為利用改變微流道之幾何形狀,使擴散物質有充分之時間於流道中擴散,進而達到快速混合之目標。本文擬先就流道設計並利用計算流體力學(CFD)工具先行模擬擴散物質於流道中之擴散情形以及流體於微流道中流動方向改變情形,而據此結果可作為將來製作相關儀器之參考基礎。
在本研究中,先利用幾種不同幾何形狀之微混合器結構進行微混合器之效率分析,然後評估各類型微混合器之特性,比較各種幾何形狀對流體混合之影響。最後本文提出之微混合器形狀為於微流道中具順序排列之方形槽。由CFD之結果顯示,在Pe數為 之階數時,流體接近均勻混合且所需之壓差約為10kpa,符合一般μ-TAS微混合器設計之要求。
而微流體開關方面,經由結果顯示利用體積流率比之方式,可對於生化流體進行引導(開關)與計量(u-liter )之功能。

In this study, CFD (Computational Fluid Dynamics) was employed as a tool to design two microfluidoic devices, passive micromixer and flow switch. In the passive mixer design, complete three-dimensional fluid and species transport equations were solved to realize the mixing effectiveness of the designed mixers. In the flow switch, Volume of Fluid method was employed in carrying out in the flow stream direction prediction.
In the passive mixer, the mixer was designed to possess triangular wavy sidewalls The basic principle is to enhance the species mixing by improving the flow exchange in the diffusive direction due to change in flow passage. The amplitude and wave number was designed to relate to the channel depth. DI water was used as the working fluid. The inlet velocity was in the range of 0.0008 to 0.8m/sec. The species molecular diffusivity was in the range from to . Based on these flow and species parameters, it was found that the minimum wave amplitude and numbers to achieve complete mixing were 5H and 8 when H=70um. The outlet channel length required to achieve complete mixing (defined as mixing length) was 8mm. By reducing the depth to 35um and maintaining the amplitude at 5H, the same mixing length was obtained but with the wave number increased to 16. However, the required driving pressures increased dramatically.
In the design of microfluidic switch, we attempt to design a simple microfluidic system that can perform flow metering and switching at the same time. From the simulation, it was found that flow metering and switching can be achieved by suitable adjustment of flow rate of the sheath flow. The test fluid can be switched into one, two, or three branches with flow rates depending on the cross section area and averaged velocity of each branch.
URI: http://hdl.handle.net/11455/2668
Appears in Collections:機械工程學系所

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