Entropy generation on EMHD transport of couple stress fluid with slip-dependent zeta potential under electrokinetic effects

Abstract

This study theoretically explores the electroosmotic and electromagnetohydrodynamic (EMHD) transport of couple stress fluid in a microchannel subjected to an applied magnetic and electric field simultaneously to predict the flow dynamics, thermal transport, and entropy generation in a thermofluidic system with slip-dependent (SD) zeta potential. Solving the linearized Poisson-Boltzmann equation gives a closed-form solution for the slip-dependent (SD) electrical potential distribution established in the Electrical Double Layer (EDL). Using suitable boundary conditions and the SD zeta potential, analytical expressions for flow velocity, temperature, and entropy generation rate are determined. There are a variety of important parameters that have been considered, including the couple stress, slip length, Hartmann number, pressure gradient, and transverse electric field. The findings for each of these parameters are graphically displayed. After accounting for the SD zeta potential for the slip parameter and Hartmann number, the fluid velocity is shown to rise; however, the normalized velocity for the couple stress parameter exhibits the reverse trend owing to its strong resistive influence. It is noticed that with a higher Brinkman number, the magnitude value of the temperature is larger for SD zeta potential than for slip-independent (SI) zeta potential owing to an increase in viscous dissipation effect. The results reveal that the flow velocity and thermal energy distribution have a substantial effect on the quantity of entropy generated in the channel under SD zeta potential.