Thermal analysis of Casson nanofluid flow with Hall and activation energy effects

Abstract

Abstract This study presents a comprehensive analysis of unsteady magneto‐convective heat and mass transport in Casson nanofluid flowing over a vertically stretching sheet within Forchheimer porous medium. The mathematical model incorporates an inclined magnetic field, Hall current, mixed convection, viscous dissipation, Brownian motion, thermophoresis, thermal radiation, and binary chemical reaction governed by activation energy. A convective boundary condition is imposed to represent realistic thermal exchange between stretching surface and surrounding medium. Using appropriate dimensionless similarity variables, we transform the governing nonlinear partial differential equations and employ the local non‐similarity method to obtain system of ordinary differential equations. The resulting boundary‐value problem is numerically solved using the MATLAB bvp5c solver. The effects of Casson parameter, Forchheimer number, Hall parameter, thermal buoyancy parameter, and radiation parameter on velocity, temperature, and concentration distributions are examined systematically. Consequently, analysis of their influence on the skin‐friction coefficient, Nusselt number, and Sherwood number is demonstrated. The results indicate that increasing Casson, Forchheimer, and Hall parameters enhances the fluid velocity while reducing thermal and concentration boundary‐layer thicknesses. An increase in magnetic parameter from 1 to 3 decreases velocity and temperature by 23.68% and 14.04%, respectively, while increasing concentration by 13.93%. When the magnetic parameter further increases from 3 to 5, velocity and temperature decrease by 21.20% and 10.67%, respectively, whereas concentration increases by 10.61%. Quadratic regression analysis further quantifies the relative influence of the governing parameters on the heat‐ and mass‐transfer rates. These findings provide useful insight in controlling non‐Newtonian nanofluid transport in porous thermal‐processing and energy‐conversion systems.