In this study, the effects of nonlinear thermal radiation, Arrhenius activation energy, and chemical reactions on the flow and heat transfer of a water-based hybrid nanofluid containing SWCNT- \(TiO_{2}\) & MWCNT- \(CoFe_{2} O_{4} \,\) nanoparticles over a rotating disk are examined. The investigation highlights the combined influence of nonlinear radiation and nanoparticle shape factors on the transport properties of the hybrid fluid. Given that the thermal and structural performance of nanomaterials is strongly dependent on their morphology, special attention is devoted to assessing the role of particle shape variations. The objective of this work is to advance the fundamental understanding of how nonlinear radiative processes, activation energy, and nanoparticle geometry interact in rotating disk flows, thereby contributing to the development of efficient nanofluid based thermal management systems. These materials find applications in energy storage, thermal stability, transistors, and electromagnetic shielding. Given the growing demand for nanotechnology, understanding these effects is crucial for enhancing performance in engineering and energy systems. The governing PDEs are simplified into dimensionless ODEs using similarity transformations. The Successive Over-Relaxation method, executed through a custom MATLAB code, is used to obtain the solutions of these equations. The effects of different parameter values on radial and transversal velocity, as well as heat and mass transfer, are examined using graphical analysis. In addition, tabular data are presented to evaluate the behavior of skin friction, Nusselt number, and Sherwood number under various parametric conditions. The results reveal that velocity diminishes with increasing magnetic parameter values, whereas nonlinear radiation enhances heat transfer. Activation energy augments both concentration and mass transfer, although the latter is influenced by the Schmidt number and the chemical reaction rate. Conversely, temperature decreases with a rise in the Prandtl number. Radial skin friction decreases by about 44% as the magnetic parameter increases, while tangential skin friction magnitude rises by nearly 78% at low suction and around 37% at high suction. Furthermore, the heat transfer rate improves from 25.27% at Rd = 0.5 to 37.18% at Rd = 1.4, indicating an overall enhancement of 11.91%. These outcomes hold practical significance for optimizing fluid behavior and heat transfer in rotating systems, with potential applications in energy systems, heat exchangers, and advanced cooling technologies.
