Mathematical modelling of Casson ternary hybrid nanofluid flow and heat transfer over a rotating disk with chemical reactions

Rotating disks involving chemical reactions find extensive applications in the medical field, particularly in optimizing chemical processes for controlled drug delivery systems, thereby improving precision in therapeutic treatments. In this study, we elucidate the behavior of fluid flow over a rotating disk with Casson ternary hybrid nanofluid with incorporation of chemical reactions. The axisymmetric flow of the rotating disk is scrutinised considering the disk’s radial shrinking/stretching and the mathematical modeling of these complex transport phenomena is governed by a set of partial differential equations. Thus, a similarity transformation approach was employed, converting the boundary layer equations into similarity equations represented as ordinary differential equations. Subsequently, the bvp4c solver in MATLAB is utilized to numerically solve the set of non-linear ordinary differential equations describing the boundary value problem. The outcomes encompass local skin friction coefficients, velocity and concentration profiles, which were determined for various values of the governing parameters. In summary, the results show that enhanced suction, a lower Casson fluid parameter, and the shrinking or stretching motion of the rotating disk notably delay boundary layer separation and reduces the skin friction. Moreover, increasing the strengths of homogeneous and heterogeneous chemical reactions markedly reduces the concentration gradients, as the accelerated reaction kinetics intensify the species conversion within the boundary layer and improves mass transfer performance. Higher stretching rates boost heat transfer by creating sharper temperature gradients near the disk surface, which indicates stronger convection and a thinner thermal boundary layer. Overall, these results offer valuable insights into optimizing heat and mass transfer in engineering systems involving non-Newtonian nanofluids under chemical reaction environments.