The optimization of Koch fractal micromixer with snowflakes structure

Abstract

The development of micromixer device has grown rapidly due to significance in miniaturization of complex biological and chemical processing system. High mixing efficiency and low Reynolds (Re) number is a key performance expected from a micromixer device in microfluidic system. The performance could be enhanced by the structure of Koch fractal arranged at the top and bottom of the T-micromixer. In this work, the mixing efficiency of different level is secondary snowflakes fractal micromixer (SSFM) and tertiary snowflakes fractal micromixer (TSFM) are compared and the thickness of Koch fractal is optimized. COMSOL Multiphysics has been used to simulate the mixing process in microchannel and the mixing efficiency for each geometry with thickness variations 0.01-0.19 mm is obtained. The influences of Re number on mixing efficiency was investigated in the range 0.05–100 also. The result has been indicated the higher level of fractal obtained the higher mixing efficiency. The homogenous mixing in the meander structure has showed as well as high mixing efficiency that reaches 0.999. Where the optimum of mixing performance is obtained by 0.18 mm of thickness at Re 0.05. Therefore, it can be concluded that the Koch fractal structure has a high performance and applicable to support the development of Lab on Chip for various application.