Cattaneo–Christov modelling of hybrid nanofluid stagnation-point flow over a rotating stretching disk with magneto-thermal coupling and entropy generation

This study numerically investigates the stagnation-point flow and heat transfer behaviour of a Cu–Al2O3/water hybrid nanofluid over a rotating and radially stretching disk subjected to convective heating and magneto-thermal coupling. The governing equations are formulated within the Cattaneo–Christov non-Fourier heat conduction framework to account for finite thermal relaxation effects. The analysis integrates several advanced physical mechanisms, including partial slip, radiative heating, magnetic field orientation and entropy generation, into a unified hybrid nanofluid model. The influence of nanoparticle geometry – brick, platelet, cylinder and spherical is systematically examined to assess its impact on the velocity distribution, temperature field and entropy production. A fourth-order accurate cubic B-spline collocation scheme is employed for the numerical simulations, with eigenvalue-based stability analysis ensuring computational robustness and precision. The results show that disk rotation enhances velocity and temperature, while slip effects weaken flow and thermal transport. Inclined magnetic fields suppress fluid motion and thicken the thermal boundary layer, particularly at negative inclination angles. Higher nanoparticle concentration improves thermal performance but reduces velocity. Stretching and rotation enhance heat transfer by up to 50.91%, whereas thermal relaxation reduces it by up to 75.33%. Entropy generation decreases with radiation and relaxation but increases with magnetic effects.