复合侧壁微结构增强被动微混合的数值模拟研究

Inspired by the microstructure on manipulation of the local flow field, T-type passive micromixer with composite lateral microstructures were established firstly. Then the flow field characteristics and mixing efficiency of the passive micromixer with composite lateral microstructure are analyzed through COMSOL numerical simulation, and the molecular diffusion under low Reynolds number and the secondary vortex effect under higher Reynolds number are studied. The results show that for molecular diffusion, the composite microstructure reduces the flow width in the microchannel, and the mixing effect is better; for the secondary vortex effect, the composite microstructure increases the number of secondary vortices in the microchannel, which can be effectively improve the mixing effect. Based on the above-mentioned numerical analysis results, in the working condition of 0.01 ⩽ Re ⩽ 50, the composite lateral microstructure and the optimal geometric parameters make the mixing index of the micromixer reach more than 85%. Compared with the built-in block type micromixers, the built-in composite lateral microstructure type micromixer has better mixing effect and smaller pressure drop.