Numerical simulation on fluid mixing by effects of geometry in staggered oriented ridges micromixers

Owing to the enhancement of surface effects at the micro-scale, patterned grooves on a microchannel remain a powerful method to induce chaotic advection within a pressure driven system. Since the staggered oriented ridges static micromixers are presented, there are few results in the literature about the geometric effects of such micromixer on the fluid mixing. This paper presents simulations within the micromixer and identifies geometric factors that affect the generation of advection flow over staggered oriented ridges. By varying the inflow directions, the ridge height ratio and the ridge asymmetry index, the modes of fluid motion and the pressure drops are studied respectively. Furthermore, through a set of numerical simulations, the relation expression between a mixing index to evaluate the mixing performance and the mentioned geometric parameters is obtained and the value of this mixing index could be calculated continuously. It indicates that the mixing performance of every staggered oriented ridges static micromixer could be estimated.