Numerical study of Casson nanofluid over an elongated surface in presence of Joule heating and viscous dissipation: Buongiorno model analysis

Nanoparticles (NPs) have wide engineering and industrial applications including improving heat transfer, cooling and heating processes, refrigeration, and medical sciences like cancer treatment etc. Further, Buongiorno model is used to determine how Brownian motion and thermophoresis affect the unsteady 2D flow of Casson nanofluid (NF) over a stretching sheet entrenched in a porous medium. The flow is exposed to an exponential heat source, thermal radiation, dissipation, Joule heating, and transverse magnetic field. The diffusion of chemically reactive NPs to base fluid has been considered. The leading equations of flow model admit similarity solution and reduce to non-linear ODEs by appropriate similarity renovations and elucidated numerically by MATLAB software using bvp4c code. It is found that incidence of NPs in the base fluid reduces the shearing stress at the plate surface so as to avoid back flow. Thermophoresis favours the rise in volume fraction and temperature of the nanofluid. Use of high- Prandtl number base fluid and NP of high thermal conductivity could be of practical use to increase the rate of heat transfer and to avoid NP accumulation.