Effect of Slip on Vortex Formation Near Two-Part Cylinder with Same Sign Zeta Potential in a Plane Microchannel

Abstract

We investigate the effect of slip on the formation of recirculation zone near the two-part cylinder with the same sign zeta potential placed in a microchannel. The external electric field is used to actuate the electroosmotic flow (EOF). The governing transport equations are solved using a finite element based numerical solver. The vortex formation takes place near the upstream part of the cylinder. The strength of the vortex is analyzed in terms of the maximum magnitude of reversed flow velocity $\left( {U_{R} } \right)$. It is found that the extent of the recirculation zone is smaller for the slip case as compared to the no-slip case. The magnitude of $U_{R}$ increases with the slip coefficient ($\beta$) for smaller values of $\beta$. Also there is a decrement in $U_{R}$ at larger values of slip coefficient and the decrement is amplified at higher values of zeta potential. The flow rate monotonically increases with the slip coefficient and zeta potential.