Numerical simulation of electroosmotic effect in serpentine channels

Numerical simulation of flow through a three-dimensional serpentine microchannel, subjected to a voltage perpendicular to the flow direction is presented here. Commercial CFD software CFD-ACE+ is used for the numerical analysis. A parametric study is conducted to investigate the effect of radius of curvature, Reynolds number, zeta potential and Debye length on the pressure drop and friction factor. Each case is compared with flow without electroosmotic effect. It is found that electroosmosis induces secondary flow patterns in the straight portion of the channel in addition to secondary vortices at bends. This electroosmosis-induced secondary flow causes additional pressure drop as compared to flow without electroosmosis. For flow with and without electroosmosis, the pressure drop increases with Reynolds number and the nature of variation is qualitatively similar in both the cases. It is also found that the pressure drop increases as the Debye length is reduced.