Title : Analysis of electroosmotic flow in a symmetric wavy channel containing anisotropic porous material with varying zeta potential
Abstract:
The present study examines an asymptotic analysis of electroosmotic flow phenomena bounded by the symmetrical wavy channel containing an anisotropic porous material under the variable pressure gradient and zeta potential. The incorporation of anisotropic porous material introduces additional complexities to the flow behaviour. Electric potential is regulated by the non-linear Poisson-Boltzmann equation, which is linearized by the Debye–Huckel linearization process and flow velocity inside the porous channel are governed by the Brinkman equation. The aspect ratio of the channel is considered to be significantly small, i.e., (δ2 ? 1). Obtaining analytical solutions to these non-linear coupled equations is a formidable challenge. Consequently, these equations have been solved using an asymptotic series expansion in terms of the small parameter, the ratio of the channel (δ2 ? 1). The fluid velocity, flow rate, flow resistance, wall shear stress, and wall pressure gradient are significantly affected by the Debye–Huckel parameter, anisotropic ratio, slip length, and amplitude of the fluctuations. The results demonstrate that an increment in the anisotropic ratio corresponds to an enhancement in fluid velocity and augmented flow rate. This relationship stems from the observed phenomenon wherein an increase in the anisotropic ratio leads to an augmentation in the permeability along the x-direction, thereby leading to an elevation in velocity and subsequently enhancing the flow rate. The study also examines the impact of flow reversal at the crests of the wavy channel resulting from the anisotropic ratio. The results of our study have validated the axial fluid velocity in pure pressure-driven flow in the absence of electroosmotic flow. These findings deepen our comprehension of the interplay between anisotropic permeability and fluid flow within microfluidic devices, particularly under the influence of electrokinetic phenomena.
