Abstract Summary (Max 250 words)
Micromixers are key components of microfluidics and are widely used in research and industry. Micromixers offer many benefits, such as rapid mixing, portability, safety, and low cost. Due to the low Reynolds numbers in microscale flows, the fluid is laminar, making it difficult to mix thoroughly, quickly, and effectively. In this study, 2D and 3D SAR-type micromixers composed of four hexagonal mixing units are proposed. Two variations of the Hexagonal mixer are designed, varying the aspect ratio (Α) and connecting angle (θ) in both 2D and 3D. The primary goal is to examine the effects of the aspect ratio and the connecting angle on mixing performance. The mixing index (MI), pressure drop, fluid flow, velocity, and mass transport are numerically analyzed employing Ansys Fluent 15 commercial software for liquid water at Reynolds numbers (Re) ranging from 1 to 200. It is evident from the numerical simulation that the mixing index depends significantly on both the aspect ratio (A) and the connecting angle (θ). In addition, the 3D Hexagonal mixer yields higher efficiency compared to the 2D mixer. The Aspect ratio equal to 1 and the connecting angle equal to 90 degrees provide the maximum efficiency, indicating 99% at Re = 200. Although the pressure drop of the 2D Hexagonal mixer is lower than that of the 3D one, the mixing energy cost (MEC) is much higher due to a lower mixing index (MI). Hence, the 3D Hexagonal mixer, especially with A=1 & θ=90°stood out as the best-performing mixer.
