Buongiorno Model of Magnetohydrodynamic Nanofluid Flow Over a Heated Stretching Sheet

Abstract

Nanofluids are important working fluids for electronic cooling in industrial, engineering, and biomedical applications. Although MHD nanofluid flow over stretching sheets has been widely studied, the combined effects of viscous dissipation, thermophoresis, Brownian motion, and a magnetic field under the Buongiorno model remain insufficiently explored. This study numerically investigates these effects, along with Joule heating and convective surface heating, on flow over a heated stretching sheet subject to a perpendicular magnetic field. Similarity transformations were used to reduce the governing partial differential equations of continuity, momentum, energy, and concentration to nonlinear first-order ordinary differential equations. The resulting boundary value problem was solved using the shooting technique with the Runge-Kutta method in the MATLAB ode45 function. Results show that the magnetic field increases the temperature through Joule heating and diminishes the convective flow through the Lorentz force. Brownian motion and thermophoretic parameters elevate the nanoparticle distribution and increase the fluid temperature. The Eckert number intensifies viscous heating, while the Prandtl number restricts thermal diffusion. The Schmidt number decreases species concentration, while the Joule heating parameter enhances the temperature near the surface. The skin-friction increases with the magnetic parameter while the Sherwood number decreases; a higher Prandtl number enhances heat transfer but reduces mass transfer, and the Nusselt number increases with the Biot number. These findings indicate that magnetic field strength and convective surface heating can be regulated to control wall shear stress and heat and mass transfer rates in plastic extrusion, metallurgy, and electronic cooling.