International Research Journal of Education and Technology

In this review presents a comprehensive assessment of computational investigations on the coupled effects of natural convection and surface radiation in extended surfaces with various fin geometries, including annular, star, square, and triangular configurations. Emphasis is placed on three-dimensional numerical studies employing the finite volume method, commonly implemented using the ANSYS Fluent solver, to solve the governing conservation equations of mass, momentum, and energy. Buoyancy effects are typically modelled using the ideal gas assumption, and numerical results are validated against previously published data.

The review synthesizes findings on the thermal behaviour and heat transfer performance of different fin geometries under a wide range of operating conditions. Key parameters such as Rayleigh number (10³–10⁶), fin spacing, surface emissivity, aspect ratio, fin orientation, and geometric modifications are systematically examined to elucidate their influence on coupled convective and radiative heat transfer mechanisms. Reported temperature distributions, flow structures, and heat transfer interactions are analysed to identify performance trends and governing transport phenomena. In addition, the review highlights the development of empirical and semi-empirical correlations linking the Nusselt number with Rayleigh number and geometric parameters for selected fin configurations. Overall, this work provides a critical and structured overview of recent numerical advances in convection–radiation heat transfer from complex fin geometries, offering valuable insights for the design and optimization of extended surfaces in heat exchangers and thermal management systems.

Keywords:- Natural Convection, Surface Radiation, Fin Geometry, Heat Transfer, Computational Fluid Dynamics, Three-Dimensional Analysis.