Entropy optimization for chemically reactive magnetized unsteady thin film hybrid nanofluid flow on inclined surface subject to nonlinear mixed convection and variable temperature

Abstract This study aims to investigate thin film flow with the effects of a magnetic field in association with Cu and CuO nanoparticles past an inclined plate. The second law of thermodynamics is used to optimize the production of entropy and to reduce the fluid’s friction. The leading equations have been solved through the homotopy analysis method in dimensionless form. It is observed that fluid motion is slowed down as the thickness factor, volumetric fraction of nanoparticles, and unsteadiness parameter increase, while it intensifies with higher values of mass and thermal Grashof numbers. The thermal distribution has augmented with an upsurge in volumetric fraction, magnetic factor, Eckert number, and unsteadiness factor. Bejan number as well as the rate of entropy production are opposed by Brinkman number and are supported by growth in magnetic factor. For nanoparticle volume fractions ranging from 0.01 to 0.03, the Nusselt number shows significant improvement, particularly for hybrid nanoparticles, where it increases from 4.3207 to 6.6983%, demonstrating their superiority over traditional nanoparticles. Validation of work has been ensured through comparative analysis between current results and published works.