The development of an efficient thermal transfer fluids presents a significant challenge in the modern industry, as the heat transfer rates of conventional fluids are inadequate for effective heating and cooling processes. Tri-hybrid nanofluids (THNFs) are considered advanced heat transfer fluids, developed through suspending three different types of nanoparticles in base fluids. This novel class of nanofluids exhibits distinct and dynamic thermophysical properties, facilitating several kinds of applications in nanotechnology and heat transfer devices. Therefore, this study examines the flow of an electrically conducting water-based THNFs over a curved stretching surface (CSS) with linear velocity. The flow is modeled using a curvilinear coordinate system, with tri nanoparticles consisting of copper oxide \((\text{CuO})\) , magnesium oxide \((\text{MgO})\) and graphene oxide \((\text{GO})\) suspended in the water. This work is novel in that it incorporates Hall current, thermal radiation, Joule heating, viscous heating, heat generation and entropy generation effects into the analysis of a \({\text{CuO}} + {\text{MgO}}{+}{\text{GO}}/{\text{H}}_{{2}} {\text{O}}\) THNFs flowing over a CSS using experimentally reported thermophysical properties. The transformed boundary layer equations of the present flow are simplified through the application of non-similar transformations and then solved numerically subject to associated boundary conditions. Flow features such as the velocity profile, Bejan number, distribution of THNFs temperature and entropy generation are evaluated for dimensionless flow parameters through graphs. Local heat transfers and skin friction coefficients are also discussed via tables. The findings of this study indicate that velocity profile increased for variations in Hall and curvature parameters for mono-particles \((\text{MgO}/{\text{H}}_{2}\text{O})\) , tri-particles \((\text{MgO}+\text{CuO}+\text{GO}/{\text{H}}_{2}\text{O})\) and bi-particles \((\text{MgO}+\text{CuO}/{\text{H}}_{2}\text{O})\) nanofluids. Additionally, the temperature distribution improves for greater values of magnetic number and radiation parameter. Furthermore, the analysis suggests that enhancing the Hall parameter and Brinkman number increase the entropy generation number, while Bejan number decreases for higher values of Brinkman number and thermal radiation parameter. The tabular results indicate that the THNFs exhibit the highest heat transfer rate compared with mono– and bi-particle nanofluids. A quantitative analysis indicates that the heat source parameter enhances the local Nusselt number by more than 240%, while thermal radiation provides up to 22% improvement. In contrast, magnetic and Brinkman numbers reduce heat transfer due to Lorentz force and viscous dissipation effects. Growth of the Hall parameter leads to an approximate quantifiable reduction of 30–35% in the skin friction coefficient, whereas an increment of the magnetic parameter leads to an increase of approximately 35–40%, with THNFs being most affected. In case of surface curvature being increased, skin friction is lowered significantly by over 30%, while the effect of the Brinkman number is negligible.
