Computational investigation of thermal energy transfer enhancement in nanofluid in the presence of viscous dissipation, Joule heating and yield stress: a local similarity approach

Abstract

Abstract Thermal transport by fluids has numerous applications, including thermal radiators, thermal and cooling systems, MHD generators, etc. In this study, the thermal transport performance of the Casson fluid is investigated in response to the inclusion of three combinations of nanoscale particles. These combinations are: (i) $$\:F{e}_{3}{O}_{4}$$ , (ii) $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ and (iii) $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ - $$\:Ni$$ . These combinations are called mono-nanoparticles, di-nanoparticles, and tri-nanoparticles, respectively. Kerosene oil is used as the base fluid. The boundary layer approximations are used for the simplification of the system of governing PDEs under local thermal equilibrium. A local similarity transformation is used to reduce the governing equations to a system of ODEs. Numerical solutions of the transformed system of BVPs using a numerical method called BVP4C. The optimization in thermal enhancement is aimed at increasing the thermal conductivity due to the dispersion of multi-nanoscale particles. A porous medium creates a resistance to the flow, which reduces the convective heat transfer. Consequently, the heat transport rate decreases. Eventually, the local Nusselt number decreases. Thus, flow in practical applications should not be in the porous medium where the local Nusselt number needs to be optimized. The viscoplasticity reduces the skin friction coefficient. Moreover, the boundary layer thickness associated with tri-nanofluid ( $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ - $$\:Ni$$ -kerosene oil) is wider than that with $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ -kerosene oil and $$\:F{e}_{3}{O}_{4}$$ -Kerosene oil. It is established in this study that kerosene containing $$\:F{e}_{3}{O}_{4},\:Co$$ and $$\:Ni$$ has the highest effective thermal conductivity in comparison with kerosene oil, having $$\:F{e}_{3}{O}_{4}\:$$ and $$\:Co$$ and kerosene oil with $$\:F{e}_{3}{O}_{4}$$ . Therefore, it is concluded that among $$\:\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ - $$\:Ni$$ -kerosene oil, $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ -kerosene oil and $$\:F{e}_{3}{O}_{4}$$ -kerosene oil, $$\:F{e}_{3}{O}_{4}$$ - $$\:Co$$ - $$\:Ni$$ -kerosene oil is the best working fluid concerning heat transport. The thermal radiations are electromagnetic waves that carry heat energy with them, and therefore, the thermal boundary layer thickness is reduced, and the local Nusselt number is increased with an increase in the thermal radiations.