Turbulent Natural Convection in a Vertical Cylindrical Enclosure With Localized Heating and Cooling

This study presents a numerical investigation of turbulent natural convection in a vertical cylindrical enclosure subjected to localized heating and cooling on opposite surfaces. The flow is driven by buoyancy forces arising from temperature gradients, leading to complex turbulent structures and enhanced heat transfer characteristics. The governing equations, including the continuity, momentum, and energy equations, are solved using a computational fluid dynamics (CFD) approach. The simulations are conducted for a range of Rayleigh numbers to examine the transition and behavior of turbulent flow regimes. Special attention is given to the influence of the spatial positioning of the heat source and sink on the flow structure, temperature distribution, and overall thermal performance. Results are presented in terms of velocity profiles, temperature distribution, turbulent intensity, and Nusselt number distributions. The findings indicate that the location of heating and cooling zones significantly affects the strength of circulation cells, thermal stratification, and heat transfer efficiency. Higher Rayleigh numbers intensify turbulence, resulting in improved mixing and increased heat transfer rates.The study provides valuable insights into optimizing heat transfer in cylindrical systems, with potential applications in energy systems, industrial heat exchangers, and post-harvest storage technologies. The outcomes contribute to the advancement of numerical modeling techniques for turbulent natural convection and offer guidance forq the design of thermally efficient engineering systems.