本研究探討具有對齊或不對齊T形匯流入口與分合流模組的微混合器，在入口處流體匯流後進入主混合流道，經由分合流模組的彎曲分岔處將流體分成上、下部分分別進入彎曲分支流道，利用彎曲流道使流體產生折疊拉伸效應促進混合，再使用T形接頭進行匯流。當匯流接頭不對齊時，會引發渦流，本研究主要探討此一渦流引發結構對微混合器之混合的影響，並比較主混合流道深寬比為2與1流體混合的情形。在高培克萊特數下，網格法會高估混合度，因此本研究進一步使用流體粒子反向追跡與近似擴散模式及反向蒙地卡羅法做模擬，本文主要以前者的模擬結果比較在微混合器中不同雷諾數的流動及混合。本研究也利用微影製程製作微混合器，並使用共軛焦顯微鏡觀察流體的混合情形，和數值模擬相互比較，發現兩者具有相似的濃度分佈。研究結果顯示主混合流道深寬比為2之具渦流引發結構分合流模組微混合器在低雷諾數時，利用分合流模組及不對齊接頭，使兩流體形成分層化的濃度分佈，大幅增加流體間接觸面積。在高雷諾數時，流體經由彎曲分支流道形成狄恩渦流，且藉由不對齊接頭引發渦流的橫向速度較大，使擴散介面產生折疊拉伸效應，因此混合度較高。

This study explores micromixers with aligned or unaligned T-shaped inlets and split-and-recombine (SAR) mixing units. After two fluids merge at the T-shaped junction, the fluids enter the main mixing channel and are divided into upper and lower streams through the circular turn of the SAR mixing units. The two streams through the SAR mixing units are combined at the T-shaped junctions. When the confluence junction is unaligned, the vortex will be induced. This study investigates the influence of the vortex-inducing structures (VIS) on the fluid mixing in the micromixer, and compares the mixing of the mixers with different aspect ratios of main mixing channel (Ar). At high Peclet number, the degree of mixing is overestimated by the grid method. Thus, we also adopt the particle-tracking simulation with an approximate diffusion model and the Monte Carlo simulation. We mainly adopt the former to analyze the flow and mixing of the fluids at different Reynolds numbers. This study also uses the lithography process to fabricate a micromixer, and a confocal microscopy to observe the images of the mixing in the micromixer. The experimental images show similar concentration distributions with those obtained by numerical simulation. The results show that the micromixer composed of SAR mixing units with VIS and Ar=2 has the higher degrees of mixing because it uses SAR mixing units and unaligned junctions to cause stratification effect of the two fluids at low Reynolds numbers, and generates Dean vortex in the curved sub-channels and induces strong swirling flow in the VIS at high Reynolds numbers.

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