Numerical analysis of unsteady Powell-Eyring nanofluid flow over a non-linearly stretching porous surface with activation energy and thermal radiation effects

The objective of this research is to investigate the time-dependent flow of Powell-Eyring fluid consisting of nanoparticles in a porous medium over a permeable surface stretching radially in non-linear manner. Impacts of suction/injection, heat source, Brownian movement, thermophoresis, activation energy, thermal radiation, and chemical reaction are invoked in the investigation. Appropriate transformation relations are used to turn the regulating PDEs into non-dimensional ODEs. The problem is tackled numerically employing the Keller-Box method on MATLAB. In view of various physical factors affecting fluid flow, temperature, and nanoparticles concentration, profiles in three categories are sketched and discussed. Besides, physical quantities of interest such as skin friction and Nusselt number are computed and expressed in tabular manner. Also, for validation of the acquired results, temperature gradient and skin friction coefficient values are compared with prior research and found to be in good agreement. It is concluded that pace of the flow, fluid's temperature, and nanoparticles concentration lessen as non-linearity in stretching of the surface increases while, opposite effect is observed on skin-friction coefficient, Nusselt number, and Sherwood number. The effect of radiation is found to improve the temperature profile and Nusselt number. Further, concluded that concentration profile magnifies for larger activation energy. The results of this study may be useful in heating and cooling systems, enhanced oil recovery, and in chemical engineering.