Electroosmotic flow and heat transfer through a polyelectrolyte-grafted microchannel with modulated charged surfaces

In this paper, the electroosmotic flow and heat transfer of incompressible Newtonian fluid through a polyelectrolyte-grafted microchannel with modulated charged surfaces are investigated. The effects of the modulated potential and polyelectrolyte layer on the velocity field and heat transfer properties in the micro-channel driven by the axial applied electric field and pressure gradient are discussed. A mathematical model is developed to describe the electroosmotic flow and heat transfer, including the Poisson-Boltzmann equations, the Navier-Stokes equations, and the energy equations. Based on the Debye-Huchel linearization assumption, the analytical solutions of the potential and velocity are obtained by the superposition principle and the stream function method. The finite difference method is used to obtain the dimensionless temperature in the energy equation. Finally, the results concerning the effects of dimensionless parameters on velocity and temperature are given in graphical form and discussed in detail. The results demonstrate that the velocity distribution exhibits oscillatory characteristics and generates vortices under the influence of the modulated charged potential sur-faces. The presence of the Polyelectrolyte layer alters the flow dynamics in the microchannel. The temperature in the fluid changes due to the Joule heating effect under the applied electric field.