Energy storage enhancement via buoyant convection of hybrid nanofluid in a hexagonal enclosure with a T-shaped fin: A computational approach

• Numerical study of buoyant convection in Casson hybrid nanofluid inside a hexagonal cavity. • Includes a T-shaped fin to enhance heat transfer. • Solved using the finite element method with a hybrid mesh. • Analyzes velocity, temperature, and Nusselt number distributions. • Relevant for thermal management and energy storage applications. Non-Newtonian flow in confined geometries is complicated, which poses computational and mathematical difficulties. There is still much to be done because these fluids experience complex rheological changes. In this work, buoyant convection in Casson fluids confined to a hexagonal enclosure with a T-shaped fin set in the middle bottom wall is investigated numerically for the first time. The bottom boundary walls and the T-shaped fin are maintained at a high temperature. The top wall provides thermal protection while the other side walls are cooled. The finite element method is used to solve a system of nonlinear partial differential equations governing the flow and heat transfer in order to capture the complex fluid dynamics and thermal behavior. In order to improve accuracy, the computational domain is discredited by combining rectangular and triangular mesh elements. To gain a deeper understanding of flow characteristics, dimensionless profiles are plotted along central and vertical cross-sections and the velocity and temperature fields surrounding the fin are thoroughly investigated. The Nusselt number along the fin surface is evaluated to determine the performance of heat transfer. The findings indicate that variations in Richards’s and Hartmann numbers increase the Nusselt number. In a variety of engineering and industrial applications, including thermal management in electronic devices, sophisticated cooling systems, polymer processing, and biomedical fluid systems where non-Newtonian behavior is common, this study advances our knowledge of heat transfer enhancement techniques in non-Newtonian fluids.