MHD mixed convective flow of Walters' B viscoelastic fluid via a nonlinear stretchable surface through a porous medium

• Walters' B visco-elastic liquid through a perpendicular stretching sheet soaked in a porous medium is analyzed. • The influences of thermal radiative fluxing and heat-generating (absorbing) components in the temperature equation. • Numerical treatment is accomplished by using the Keller box algorithm. • The magnetic force improves the temperature outline whilst slowing down the rates of heat conduction. This article considers the numerical analysis of a mixed convective flow of Walters' B viscoelastic liquid through a perpendicular stretchable surface embedded in a porous medium. The behavior of heat transfer characteristics is analysed by accounting for the influences of thermal radiative flux and heat-generating (absorbing) components in the temperature equation. Boundary layer equations are the basic partial differential equations (PDEs) guiding the flow and heat transmission problems. By employing the proper similarity transformations, such equations are converted into nonlinear ordinary differential equations (ODEs). The consequential boundary value problem is dealt with using the Keller box strategy (KBS). The outcomes display that the magnetic parameter enhances the temperature field while suppressing heat transfer rates, whereas stronger mixed convection reduces the thermal boundary layer thickness. The viscoelastic parameter is found to support higher surface heat transfer, and increased permeability leads to greater shear stress at the wall. This Keller box strategy (KBS) provides a numerical solution of fluid properties subject to problem constraints. This work has a significant impact, with practical applications in polymer processing, cooling systems, and other industrial processes involving viscoelastic fluids in porous media.