Rotational flow dynamics of electroosmotic transport of couple stress fluid in a microfluidic channel under electromagnetohydrodynamic and slip-dependent zeta potential effects

In this article, the role of slip-dependent (SD) zeta potential in the hydrodynamic characteristics of mixed electromagnetohydrodynamic (EMHD) and electroosmotic driven flow of couple stress fluid within a rotating microfluidic channel is theoretically investigated. This work is the first to analyze the hydrodynamic characteristics of slip-independent (SI) and slip-dependent (SD) zeta potentials in a rotating microchannel including a detailed analysis of Ekmann spirals in the microchannel. Ekmann spirals show the effect of rotational flow caused by different parameters, particularly, the slip parameter and the Hartmann number being the most significant ones. Ekmann plot variations, observed under both SI and SD model cases, show a significant effect on rotating flow dynamics. The effect of pertinent parameters on the rotational flow velocity, centerline velocity, and volumetric flow rate is graphically depicted. The findings of this research reveal that the SD zeta potential plays a crucial role in determining the rotating flow velocity and volume flow transport. The normalized transverse centerline in the magnitude flow velocity increases with the couple stress parameter and decreases with the slip parameter for both SI and SD model cases. Notably, the magnitude of the normalized transverse flow rate increases with rotational parameter values. In contrast, it decreases with an increase in the slip parameter under the SD model case. The outcomes of this study can be directly used in applications like transportation of biofluid models in Lab-On-a-Chip (LOC) devices and microfluidic systems under certain conditions.