Numerical simulation of heat and mass transfer in non-Newtonian Casson nanofluids driven nonlinearly by a wedge-shaped stretching plate

• Nonlinear stretching motion of nanofluids in an inclined stretching plate. • Magnetic field parameters and Darcy parameters can enhance fluid heat transfer . • Magnetic field and velocity ratios make the Bejan number shift to the right. In this paper, the heat mass transfer and entropy production of a non-Newtonian Casson nanofluid under the nonlinear motion of a wedge-shaped stretching plate are investigated. The effects of magnetic field, free flow velocity and porous medium are fully considered in the control equations. Then, the control equations are transformed into ordinary differential equations by using similar transformations, and the effects of dimensionless parameters on the momentum, heat and mass transfer and entropy production of the fluid are solved by using numerical solution methods. The results show that increasing both the magnetic field parameter and the Darcy parameter can effectively improve the heat transfer of the nanofluid, but at the expense of frictional resistance. It is also found that when the magnetic field strength and the velocity ratio parameter are increased, the Bejan number distribution shifts to the right overall, which can be explained by the increase in the proportion of entropy production due to heat transfer in the nanofluid system. This study theoretically deepens the understanding of non-Newtonian Casson nanofluid flow properties, and also provides a key theoretical basis for engineering applications such as heat exchanger design. In this paper, the boundary layer and entropy production problems of non-Newtonian Casson nanofluids under the nonlinear motion of a wedge-shaped stretching plate are investigated. The control equations are first listed based on conditional assumptions. Secondly, the control equations are transformed similarly to yield the ordinary differential equations. Finally, the ordinary differential equations are derived from the boundary conditions and the entropy production equations are defined to find the velocity field, temperature field, concentration field and entropy production distribution. Therefore, the dimensionless parameters can be varied to realize the laws affecting the velocity field, temperature field, concentration field and entropy production under different conditions.