Magneto-thermal transport analysis of a Casson tri-hybrid nanofluid over a spinning disk with induced magnetic field effects: An entropy analysis

This paper is an exploratory work that examines the magneto-thermal flow of a Casson tri-hybrid nanofluid of nanoparticles suspended in blood on top of a rotating disk. The mathematical model takes into consideration the effects of applied magnetic field, resistance of the porous medium, nonlinear thermal radiation and Cattaneo-Christov theory of heat flux. The ensuing nonlinear governing equations are reduced to ordinary differential equations and are solved numerically by use of a fourth order Runge Kutta method in combination with a shooting technique. The effect of major physical parameters on radial and azimuthal velocities, temperature distribution, generated magnetic field, entropy generation, Bejan number, skin friction, and Nusselt number is investigated. The findings indicate that, as the Casson parameter is increased fluid motion is suppressed as temperature and entropy production are augmented by the augmented internal resistance. The rotation of a disk enhances the velocity of the azimuthal and magnetic induction and the presence of the higher magnitude of magnetic fields slows down the velocity of the flow using the Lorentz forces. The increase in porosity reduces the transport of momentum, whereas the effects of thermal relaxation cause the decrease of the temperature in the boundary-layer. Thermal gradient and increment of temperature ratio are considerably enhanced by thermal radiation and temperature ratio. It has been identified that rotation, magnetic effects, porosity, and viscous dissipation are very sensitive in terms of the values of skin friction and heat-transfer rates. The findings, in general, shed some light on coupled thermal, magnetic, and rheological processes controlling the tri-hybrid nanofluid flow, and its possible uses in the biomedical cooling and hyperthermia therapy, as well as in the complex heat-transfer technology.