本研究探討了微流道在匯流處(junction)和流道側壁加入三角形結構引致之聲射流(Acoustic Streaming, AS)對其混合性能之增益。聲射流在T 和 Y 型微流道之匯流處和出口側壁處產生，並以微粒影像測速儀（Micro Particle Image Velocimetry, μPIV）量測在不同的三角形頂角、振幅、振盪頻率和流速下研究了由交界處的中心三角形結構引起的射流流動模式。混合之過程則使用綠色螢光染料溶液和去離子水加以模擬，並透過分析拍攝之螢光強度影像以混合度(degree of mixing) M為性能指標進行量化分析。實驗結果表明，T型微流道在流道位置y=2.15mm處的混合性能因聲射流而得到了增強，混合度M_T從0.4017提高到0.769。聲射流的性能增益在較低流速、較尖銳頂角和較高振幅下具有更好的表現，使 M_T分別從0.369上升到0.769、0.31 到0.530 和0.394到0.652。聲射流的效果進一步透過二維的數值模擬進行研究，數值模型使用了 Navier-Stokes方程式和對流擴散方程式來探討Y型微混合器中多種不同的三角形結構放置位置之配置。模擬結果顯示，在匯流區使用單個三角形結構產生聲射流可將混合度M_Y從0.6642提高到0.8355，而在匯流區與側壁使用三個三角形結構可進一步提高M_Y到0.9981。最後，以實驗驗證了模擬的結果顯示，分別使用單個和三個三角形結構組合，在 2µL/min 入口流速、13kHz 和 33V 振幅下，產生之聲射流可使M_Y由0.380提高到0.7322 和0.894。在這些實驗案例中，不同的輸入參數，如流體流速、振幅功率、三角形頂角等都會影響流動模式和混合性能，而在 y = 2.15mm處的混合度M_Y在入口流速從 1 增加到 8.5µL/min 時從 0.901 逐漸減小到 0.465，隨著幅度從50V減小到10V 時則從0.925 減少到0.444。而當中心單一三角形結構之頂角從〖30〗^o增加到〖82.37〗^o 時，以入口流速3.5µL/min，輸入電壓33V，頻率13kHz的條件下M_Y則從0.570減小到0.365。這些結果說明加入匯流區單一三角形結構對於聲射流引致之匯流微混合器之混合性能能夠有效提升，且與邊壁三角形結構能夠相互提升其效能。

In this study, the mixing performance of microchannel with acoustic streaming was investigated by inducing triangular structures at the junction and channel walls. The acoustic streaming was generated in both T and Y- microchannels at the junction and outlet sidewalls. Experimentally, the acoustic streaming flow patterns induced by a central triangular structure at the junction were first investigated using micro-particle image velocimetry (µPIV) in different triangle top vertex angles, amplitude, oscillation frequency and flow rate. The mixing process was studied using fluorescent green dye solution and de-ionized water, and the degree of mixing was quantified by introducing the standard deviation. The experimental results indicate that a mixing performance was enhanced for the T-junction microchannel at flow length y = 2.15mm, and "M" _"T" was improved by acoustic streaming from 0.4017 to 0.769. Acoustic streaming had a better impact at the low flow rate, sharp vertex angle, and high amplitude, resulting in M_T decreasing from 0.769 to 0.369, 0.530 to 0.31, and 0.652 to 0.394, respectively. The acoustic streaming was then created through 2-D numerical simulation with a model that utilizes Navier-Stokes equations in conjunction with convection-diffusion equations to study more configurations of the triangular structure’s placement positions in a Y-junction micromixer. The simulation results show that the application of acoustic streaming can improve "M" _"Y" from 0.6642 to 0.8355 using a single triangular structure in the junction region, and further improved to 0.9981 with three triangular structures on the junction and side walls. Finally, the simulation results were verified by experiments. It shows that "M" _"Y" improved with acoustic streaming from 0.380 to 0.7322 and 0.894 at 2µL/min inlet flow rate, 13kHz, and 33V amplitude using single and three triangular structure combination, respectively. Throughout all studies, different input parameters such as fluid flow rate, amplitude power, triangle vertex angle, and others influence the streaming flow patterns and the mixing performances. The degree of mixing "M" _"Y" at y = 2.15mm gradually decreased from 0.901 to 0.465 when the inlet flow rate increased from 1 to 8.5µL/min, and from 0.925 to 0.444 as the amplitude reduced from 50V to 10V, respectively. Similarly, "M" _"Y" decreased from 0.570 to 0.365 when the vertex angle of the central single junction triangle increased from 〖30〗^o to 〖82.37〗^oat 3.5µL/min inlet flow rate, 33V amplitude and 13kHz frequency.

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