NUMERICAL SIMULATION OF MICROMIXING ENHANCEMENT UNDER PERIODIC ELECTROOSMOTIC FLOW
Abas Ramiar, Mohammad Alipanah Rostami, Amirhosein Ghasemi, Siamak Saeidi-Haghi
Babol Noshirvani University of Technology, Iran
In recent years, one of the most popular themes of interest was lab-on-a-chip (LOC) which has drawn many attentions due to a broad range of medical and chemical applications in which the micro-mixers do play a major role within the investigations. In this paper, a new kind of micro-mixer based on electroosmotic driving force has been studied which T-shaped geometry with two inlets were implemented for LOC applications due to its simplicity. The present simulation was done numerically by developing a code within the open source OpenFOAM CFD package. For simulating electroosmotic flow, Poisson Boltzmann (PB) model was used and the relevant equations were added to the base solvers of the OpenFOAM. Working fluids in the simulations were pure water and water with fluorescence. Having a relatively low Reynolds number and the presence of laminar flow in micro-mixers, diffusion is not solely able to create an appropriate mixing in micro-mixers. As a result, to increase the mixing quality in micro-mixers, other kinds of methods should be applied. In this paper, a pulsatile electric field is used to improve the mixing of the fluids, where the most efficient frequency of the micro-mixer to achieve the highest mixing quality is also obtained. Moreover, the effect of conductive edges in micro-mixers has been investigated. Upon the presence of conductive edges, strong vortices were created, which led to better flow mixing and consequently an improved mixing.