Exploring the significance of nanoparticle shapes and the impact of thermal radiation on MHD viscoelastic nanofluid flow in porous channels

This study investigates analytically the influence of nanoparticle shapes on an unsteady mixed convective viscoelastic MHD nanofluid flow in a horizontal channel with oscillating walls in a saturated porous medium. The effect of radiation is also considered in the energy equation. The considered NPs are Cu, Ag, Al2O3, TiO2, and Fe3O4, with base fluids H2O and C2H6O2. The considered different shapes of NPs are cylinder, platelet, blade, and brick. The study examines three flow situations based on physical boundary conditions. The perturbation method is employed to solve the flow governing equations for three different flow situations based on physical boundary conditions: Case (i) flow in a horizontal channel with both lower and upper walls stationary; Case (ii) the upper wall of the channel is in oscillation while the lower one is constant; Case (iii) both walls of the channel are in oscillatory motion. The velocity and temperature distributions, as well as the skin friction coefficient and heat transfer rate, are analyzed through graphs and tables to assess the impact of various governing parameters. From the results, it is found that brick-shaped NPs exhibit more strength to the velocity and temperature distributions, followed by cylinder, platelet, and blade for both water-based and EG-based NF.