Magneto-micropolar nanofluid flow through the convective permeable channel using Koo–Kleinstreuer–Li model

Abstract

The major purpose of this paper is to determine the heat and flow properties of a non-Newtonian micropolar nanofluid through a micropolar channel having porous walls in the presence of a changing magnetic field by investigating the hydrothermal behavior. One of the plates gets heated from outside through some external source, while the other, into which the cold fluid is introduced, dilate, or shrinks over time. The effect of aluminum oxide (Al2O3) nanoparticles with H2O as base fluid is studied. The KKL (Koo–Kleinstreuer–Li) model is operated to determine the influence of thermal conductivity and viscosity of the nanofluid. The unsteady Navier–Stokes equations of the problem have been simulated in terms of similarity transformation whose results are reduced to a generalized Proudman–Johnson equation, retaining the effect of wall motion with physical conditions. The mathematical results for the stream function and heat transfer characteristics are determined using the shooting technique. MATLAB software is used for the numerical operations. Graphical outcomes are discussed in detail for the several physical parameters and associated dynamic characteristics especially expansion ratio, power low index, Reynolds number, Prandtl number, angular/microrotation velocity, volume fraction, and Hartman number on the velocity and temperature distribution. As the Hartmann number rises, it is observed that the fluid’s velocity reverses from the lower to higher portions of the cylinder. The microrotational velocity also gets higher for the higher Hartmann number.