Mixing performance analysis of the novel passive micromixer designed by applying fuzzy grey relational analysis

Abstract In this paper, we performed a numerical study on a passive baffled T-micromixer with two parallel inlets. The baffled structure is applied to improve the contact surface of two liquid streams under peristaltic flow. This article proposes a comprehensive evaluation value Ma to evaluate the mixing ability of micromixers on the basis of mixing efficiency and pressure loss. The mixing performance of various micromixers is investigated at Re = 0.01. Then, the 16 cases based on the four geometrical parameters (inclined angle, depth, width, and distance between neighboring baffles) are selected by the orthogonal experiment design method. The optimal structure and the most important influence factor on the mixing process are analyzed according to fuzzy grey relation theory. Results showed that the fuzzy grey relational grades of the incline angle of baffles to the mixing performance are the highest. According to the proposed results and the relevant research, four novel S-type stagger baffles (STSB) are proposed and investigated in further work. The micromixers with STSB could acquire a high mixing ability value from 1.47 to 1.63 at Dc = 1e-11 m2/s. The optimal design, STSB-30, can obtain high mixing efficiency at 88.2%, whereas the base micromixer achieves only 38.9% at the same working condition. This work could provide a great analytical method for relational multi-factor study and the novel structure design about mixing performance problems.