Magnetohydrodynamic nonlinear thermal radiative heat transfer of nanofluids over a flat plate in a porous medium in existence of variable thermal conductivity and chemical reaction

Abstract

The effects of variable thermal conductivity and first-order chemical reaction on magnetohydrodynamic (MHD) flow with nonlinear thermal radiation of nanofluid over a flat plate in a porous medium have been studied in this paper. The governing system of ordinary differential equations has been solved numerically. Numerical results are presented both in tabular and graphical forms for solid volume fraction φ (), magnetic field parameter M (), permeability parameter P (), variable thermal conductivity parameter ε (), thermal radiation parameter Nr (), wall temperature excess ratio parameter (), Schmidt number Sc () and chemical reaction parameter λ () illustrating the effects on the velocity, temperature and concentration as well as on the skin-friction coefficient, local Nusselt number and local Sherwood number for four types of metallic or non-metallic nanoparticles, namely copper (), alumina (), titanium dioxide (TiO ) and silver (Ag) in the base-fluid water (Pr=6.8). The obtained results show that the effects of increasing the values of the variable thermal conductivity and wall temperature excess ratio parameters there is a decrease in the local Nusselt number value.