Analytical study of pulsatile mixed electroosmotic and shear-driven flow in a microchannel with a slip-dependent zeta potential

The escalation of zeta potential by the influence of wall slip for the electrokinetically modulated flow through a microchannel motivates to consider the impact of hydrodynamic slippage upon the zeta or surface potential. The reported study undergoes an analytical exploration of the pulsatile electroosmosis and shear-actuated flow characteristics of a fluid with a Newtonian model through a microchannel with parallel plates by invoking the reliance of a zeta or surface potential on slippage. The linearized Poisson-Boltzmann and momentum equations are solved analytically to obtain the explicit expression of the electrical potential induced in the electrical double layer (EDL), the flow velocity field, and the volumetric flow rate for an extensive span of parameters. The velocity field proximal to the microchannel wall is observed to enhance by an apparent zeta potential, and is further escalated for a thinner EDL and an oscillating electric field with a higher amplitude. However, near the core region of the microchannel, the flow velocity becomes invariant with the EDL thickness. The result shows that the lower wall velocity contributes to the flow velocity along with the electroosmotic body force and the impact of the velocity of the wall underneath diminishes proximal to the upper wall. Moreover, the volumetric flow rate increases when the thickness of the EDL decreases, owing to the influence of the wall slip. However, for thinner EDLs and medium and higher oscillating Reynolds numbers, the volumetric flow rate varies non-monotonously, correlative to the slip-free and slip cases.