本研究以計算流體力學為工具，以三維T型管為基本構型的混合器，在低雷諾數下以流體擴散原理為混合機制，探討兩流體達到99%混合程度時所需要的管道長度(L99%)、管道俯視面積，及推動流體經過混合器所需的壓力差與T型管的幾何參數之關係。研究結果顯示，減少混合器中流體所需擴散的距離可有效減少L99%。同時，維持T型管主流道的截面積不變可有效降低推動流體所需之壓差。

This study adopts Computation Fluid Dynamics (CFD) as the research tool to study the mixing efficiency of various designs of 3-dimensional T-tube micromixers. The mixer design is based on the principle of molecular diffusion at low Reynolds number flow regime. Taking the length of the tube required for 99% mixing efficiency (L99%), as the principal design parameter, this study discusses the relationship among L99%, the diffusivity, the volume flow rate through the mixer, the cross sectional area of the tube, the hydraulic diameter of the tube, the pressure difference required to drive the flow, and the top view area of the mixer. It is found that keeping a constant cross sectional area is an effective way to prevent the increase of pressure difference across the mixer. It is also found that by reducing the diffusion distance of the mixer, the required L99% can be effectively reduced.

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