Heat and mass transfer in radiative magnetohydrodynamics stagnation flow of upper-convected Maxwell fluids over porous sheets with applications to industrial thermal processing

• MHD UCM fluid flow over a porous sheet with multiple transport effects. • Nonlinear PDEs solved via similarity transformation and bvp4c. • Analyzed velocity, temperature, concentration, and corresponding fluxes (heat, mass, momentum). • Industrial relevance to reactors, insulation, and heat exchangers. Heat and mass transfer are integral aspects of industrial processes, particularly in systems involving non-Newtonian fluids and magnetic fields. Industrial processes are often affected by physical effects such as heat source/sink, viscous dissipation, chemical reactions and thermal radiation. The present work focuses on incorporating these effects through a numerical investigation of MHD flow of a non-Newtonian UCM fluid over a porous sheet. A model is formulated with suitable boundary conditions, yielding a system of partial differential equations governing fluid flow, which are coupled and nonlinear. The governing equations form a system of nonlinear partial differential equations, which is partially decoupled through a suitable similarity transformation, resulting in a reduced system of ordinary differential equations amenable to numerical treatment. These governing equations are then solved numerically using the shooting technique in combination with the fourth-order Adams–Moulton method. Numerical results reveal that increasing magnetic field strength and Deborah number suppress the flow velocity, while higher Eckert and Prandtl numbers enhance the temperature field due to viscous dissipation and reduced thermal diffusivity. Chemical reaction and Schmidt numbers significantly reduce species concentration. Quantitatively, increasing porosity from K = 0 to K ≈ 0.9 lowers velocity and concentration by about 25–35%, while raising temperature by nearly 15–20%, depicting the strong sensitivity of transport processes to porous, thermal memory, and diffusive effects. Thus, the results provide an accurate description of fluid flow processes in catalytic reactors, thermal insulation systems, and heat exchangers involving chemical reactions.