Theoretical aspects of nanofluid peristaltic transport in tapered wavy structure.

This study presents a theoretical investigation of the peristaltic transport of a third-grade nanofluid in a two-dimensional tapered wavy channel under the combined influence of electroosmotic effects and slip boundary conditions. The model incorporates variable viscosity and variable thermal conductivity to represent more realistic thermophysical behavior of the fluid. In addition, the influence of nanoparticle shape on the thermal performance of the nanofluid is examined by considering three different geometries, namely brick, spherical, and platelet-shaped nanoparticles. The Hamilton-Crosser model is employed to account for the enhancement of effective thermal conductivity due to nanoparticle morphology. The governing equations for momentum, energy, and concentration transport are formulated and transformed into a dimensionless form using appropriate similarity transformations. By applying the long-wavelength and low Reynolds number approximations, the resulting nonlinear coupled ordinary differential equations are simplified and solved numerically using the shooting method. The effects of key physical parameters, including electroosmotic parameters, slip parameters, nanoparticle shape factors, and thermophysical properties, on velocity, temperature, and concentration profiles are analyzed through graphical illustrations. The results indicate that nanoparticle shape plays a significant role in heat transfer enhancement, with platelet-shaped nanoparticles producing stronger thermal and velocity responses compared with spherical and brick-shaped particles. Moreover, electroosmotic forces and slip conditions significantly influence the flow behavior within the channel. The findings provide useful insight into nanofluid transport mechanisms in bio-inspired microfluidic systems and may have potential applications in biomedical engineering, drug delivery technologies, and advanced microchannel heat transfer devices.