Finite-speed thermal transport analysis in Carreau hybrid nanofluid flow subject to a rotating curved surface

This study explores heat and mass transfer in a two-dimensional Carreau hybrid nanofluid flowing over a rotating curved surface under the effects of heat generation, chemical reaction and viscous dissipation. Such fluids are important because they enhance the performance of modern thermal systems, including turbine parts, rotating cooling devices, and curved heat exchangers. Here, graphene and titanium dioxide nanoparticles are mixed with polyethylene glycol-400 to improve the thermal properties of the base fluid. The novelty of this work lies in combining curved geometry, surface rotation, non-Newtonian Carreau fluid behavior, and the Cattaneo-Christov model for heat and mass flux in a single analysis. Unlike the traditional Fourier and Fick laws, this model considers relaxation time effects, giving a more realistic picture of thermal and concentration transport. Similarity transformations are employed to transform the nonlinear governing equations into ordinary differential equations, followed by their solution using the optimal homotopy analysis method. The results demonstrate that as the curvature parameter increases strengthens the velocity field near the surface, while thermal relaxation raises the temperature distribution.