Joule heating and viscous dissipation effect on electroosmotic mixed convection flow in a vertical microchannel subjected to asymmetric heat fluxes

Michael O. Oni *, Basant K. Jha

Department of Mathematics, Ahmadu Bello University, Zaria, Nigeria

Abstract: The impact of Joule heating due to electric double layer (EDL) and viscous dissipation on electroosmotic mixed convection flow in a vertical microchannel with asymmetric heat fluxes is established in this article. The Poisson-Boltzmann, momentum and energy equations representing the electric potential, velocity profile and temperature distribution in the microchannel are obtained in dimensionless forms. Using the Debye-Hückel linearization, exact solutions are obtained for electric potential, velocity profile and temperature distributions by method of undetermined coefficients in the absence of viscous dissipation and Joule heating while an inbuilt Matlab function called pdepe is employed to solve the coupled nonlinear momentum and energy equations in the presence of Joule heating and viscous dissipation. Results show that the presence of Joule heating and viscous dissipation lead to decrease in velocity profile and temperature distributions throughout the microchannel.

Keywords: Electroosmotic flow; Vertical microchannel; Joule heating; Heat flux; Viscous dissipation