Magnetohydrodynamic (MHD) flow of a nanofluid over a stretching surface with suction and slip effects

Magnetohydrodynamic (MHD) nanofluid flow over stretching surfaces plays an important role in many thermal engineering applications, particularly in systems where enhanced heat transfer and flow control are required. This study examines the influence of magnetic field, suction, velocity slip, velocity ratio, and nanoparticle volume fraction on the flow and heat transfer characteristics of nanofluids over a stretching surface. Three types of nanoparticles are considered, namely copper (Cu), aluminium oxide (Al₂O₃), and titanium oxide (TiO₂). The governing nonlinear partial differential equations representing the conservation of mass, momentum, and energy are transformed into a system of ordinary differential equations using similarity transformations. The resulting equations are solved numerically using the bvp4c solver in MATLAB. The numerical results show that the magnetic field and suction parameters enhance both the skin friction coefficient and the local Nusselt number, indicating stronger wall shear and improved heat transfer. Increasing the nanoparticle volume fraction improves the thermal performance of the fluid due to higher effective thermal conductivity, although excessive concentration increases viscosity and affects the velocity distribution. Among the nanofluids considered, Cu provides the highest heat transfer performance, while Al₂O₃ offers a more practical balance between thermal efficiency, stability, and cost. These findings highlight the potential of MHD nanofluids with slip and suction effects for improving thermal management in engineering and industrial heat transfer systems.