Chemically reacting and radiating nanofluid flow past an exponentially stretching sheet in a porous medium

Abstract

The influence of non-uniform permeability, thermal radiation and variable chemical reaction on three-dimensional flow of an incompressible nanofluid over an exponentially-stretching sheet in association with a convective boundary condition has been investgated. In the present study, a new micro-convection model known as Patel model has been employed to enhance the thermal conductivity and hence the heat transfer capability of nanofluids. In the present analysis, base fluids such as water, 30% ethylene glycol, 50% ethylene glycol and nanoparticles such as Cu, Ag and Fe₃O₄ have been considered. With the help of some suitable transformations the governing partial differential equationsare converted into a set of ordinary differential equations which have beeen then solved numerically by using fourth-order Runge-Kutta method along with shooting technique. The influence of various embedded physical parameters have been explored through graphs for velocity, temperature, concentration, skin friction, local Nusselt and Sherwood numbers. The resistive force offered by the porous matrix belittles the momentum boundary layer and helps in growing the temperature and concentration boundary layers. Fluid temperature is an increasing function of radiation parameter Rd and Biot’s number Bi whereas concentration field is a decreasing function of Schmidt number Sc and chemical reaction parameter γ.