Numerical simulations for optimised flow of second-grade nanofluid due to rotating disk with nonlinear thermal radiation: Chebyshev spectral collocation method analysis

The optimised flow of nanofluids is quite essential to improve the thermal mechanism of various reacting materials. The entropy generation phenomenon is essential to avoid heat losses in thermal transport systems, heating processes and various engineering devices. In this theoretical analysis, the aspects of entropy generation is presented for time-independent second-grade nanomaterials for disk flow which shows rotating behaviours. The second-grade constitutive relations result in highly nonlinear differential equations. The effects of MHD, nonlinear radiation and chemical reaction are manifested in momentum, heat and concentration equations. Precise numerical treatment for a wide range of non-Newtonian fluid parameters was adopted to tackle the resulting similarity equations. The fluctuation against the heat transfer system, wall shear stress and mass changing phenomenon were also calculated and examined for various parametrical values. The interesting Chebyshev spectral collocation numerical simulations were performed to present the solution. This research finds that the entropy generation and Bejan number show the same trend for temperature and concentration difference parameters, whereas an opposite trend can be seen for the fluid and magnetic parameters. Also, entropy generation increases for diffusion parameter and Brinkman number, but Bejan number shows two trends.