Functional magnetic Maxwell viscoelastic nanofluids for tribological coatings- a model for stretching flow using the generalized theory of heat-mass fluxes, Darcy-Forchheimer formulation and dual convection

Abstract

A theoretical and computational study of an improved Fourier and Fickian model for locally non-similar magnetohydrodynamic Maxwell (non-Newtonian) nanofluid convective flow under thermo-solutal buoyancy forces in a non-Darcian (Darcy-Forchheimer) porous medium is presented. Heat sink/source is included. Buongiorno’s two-component nanofluid model is used to simulate nanoscale characteristics featuring thermophoresis and Brownian diffusions. The problem under consideration is formulated utilizing fundamental relations of fluid dynamics. The primitive partial differential expressions (PDEs) are transfigured to ordinary ones with apposite transformations. The emerging locally non-similar boundary value problem is solved via series expansions utilizing a homotopy algorithm. Characteristics of sundry parameters on velocity, temperature, nanoparticle concentration and skin-friction coefficients are interpreted graphically. Convergence results acquired via homotopy algorithm are presented. Comparison results are included for the authentication of the homotopy solutions. The velocity distribution is increased with greater mixed convection and non-Newtonian material parameters whereas velocity distribution is reduced with increment in Hartmann (magnetic) number, porosity and buoyancy ratio parameters. The temperature distribution is reduced when Prandtl number and thermal-relaxation (non-Fourier) parameter are augmented whereas temperature distribution is increased for larger Brownian diffusion and thermophoresis. Additionally, it is observed that increment in the heat absorption variable diminishes temperature whereas an enhancement in the heat generation variable augments temperature. Nanoparticle concentration is enhanced subjected to higher values of thermophoresis factor whereas it reduces with larger Schmidt number, Brownian movement and solutal-relaxation (non-Fickian) parameters. Furthermore, it is noticed that elevation in Hartmann number, porosity and inertial (non-Darcy) coefficient parameters increase the skin friction coefficient whereas elevation in Deborah number and buoyancy ratio is found to suppress skin friction. The simulations are relevant to hydromagnetic nano-materials processing operations for coatings deployed in multi-functional tribological systems and surface protection.