Computational analysis of unsteady and steady magnetohydrodynamic radiating nano fluid flows past a slippery stretching sheet immersed in a permeable medium

This work gives an account of unsteady and steady radiating magnetohydrodynamics (MHD) nanofluid flow over a slippery stretching sheet embedded in a porous medium. A widely used similarity variables of such flows reduces a governing partial differential equations (PDEs) into a new set of partial differential equations (PDEs) in which a dependent variable is a function of two independent variables rather than three. At the same time, third order PDEs are converted into a second order PDEs by defining a new variable wherever it is deemed necessary. For the time integration, we perform first order explicit Euler method and spatial derivatives are approximated by the finite difference formulas in the context of node-centered finite volume method. It is revealed that for the unsteady flow the temperature of the nanofluid is higher near the surface without thermophoresis parameter Nt and reduced significantly when Nt is present. We also show that the concentration boundary layer thickness decreases with an increase of Darcy number Da.