Theoretical investigation of electromagnetohydrodynamic flow of a couple stress fluid through a circular microchannel

This study assesses the dynamics of electromagnetohydrodynamic (EMHD) flow of couple stress fluid through a circular cylinder. The flow is assumed to be driven by electromagnetic force and applied pressure gradient. A comprehensive theoretical framework is developed to solve the Poisson–Boltzmann equation (under the Debye–Hückel approximation) for the electric potential within the electric double layer and the momentum equation for the fluid flow under suitable boundary conditions. The analytical expressions are obtained for velocity and volume flow rate. It is observed that the present results of the couple stress fluid (CSF) model strongly match with those reported in the literature for a Newtonian fluid. The outcome of our analysis reveals that the velocity accelerates with an increase in couple stress and electric field parameters, while it decreases with Hartmann number in the absence of lateral electric field. The study finds major applications in chemical processing and mixing, development of biochips for drug delivery and biomedical engineering.