Electro-osmotic and thermal transport of Casson fluids in membrane-actuated microchannels with velocity slip

The study examines the electro-osmotic flow and heat transfer properties of Casson fluid in a microchannel, considering the effects of slip boundary conditions. The analysis incorporates the combined effects of non-Newtonian fluid behavior, electrokinetic body forces, and thermal gradients to better understand flow dynamics in microscale systems. The fluid flow is characterized by the continuity, momentum, and energy equations, while the distribution of electric potential for the electrolyte solution in the direction normal to a charged surface is examined using the Poisson-Boltzmann equation. Utilizing the low Reynolds number assumption and Debye-Hückel linearization, the governing equations were derived. Dimensionless conservation equations are solved analytically under slip boundary conditions, and the solutions are calculated using MATLAB. The axial velocity results are validated and simulated with the finite difference method. The model discusses how important variables influence volumetric flow rates, skin friction, stream function, isotherms, velocity profile, and pressure distribution. The results indicate that the fluid velocity along the walls is enhanced by slip. Additionally, the electro-osmotic phenomena are also noted to control the flow close to the wall due to the electric double layer, profoundly affecting both the temperature and velocity distributions. The Casson parameter is found to dampen the velocity and increase the thickness of the thermal boundary layer. These results give useful insight into the design and optimization of electrokinetically driven microfluidic devices for biomedical and cooling applications.