Thermal and flow characteristics of hybrid nanofluids in free-forced convection under suction/blowing effects

This study investigates mixed convection magnetohydrodynamic (MHD) flow and heat transfer of a $A{l}_2{O}_3--Cu$/water hybrid nanofluid over stretching and shrinking surfaces embedded in a porous medium, incorporating the simultaneous effects of suction/injection, thermal slip, viscous dissipation, Joule heating, and thermal radiation. The governing boundary layer equations were transformed using similarity variables and solved numerically with the MATLAB bvp4c solver, employing experimentally validated thermophysical property correlations. Parametric analysis reveals that suction enhances heat transfer by thinning the momentum and thermal boundary layers, while injection reduces it. Magnetic fields and higher nanoparticle loadings increase fluid temperature but reduce the Nusselt number. Thermal slip improves wall heat transfer, whereas viscous dissipation, Joule heating, and radiation diminish it by thickening the thermal layer. Higher Prandtl numbers yield thinner thermal boundary layers and greater heat transfer efficiency. The findings provide useful design insights for thermal systems employing hybrid nanofluids in porous and magnetically influenced environments.