Thermally Driven Flow of Water in Partially Heated Tall Vertical Concentric Annulus.

Computational fluid dynamics (CFD) has become effective and crucial to several applications in science and engineering. The dynamic behavior of buoyancy induced flow of water in partially heated tall open-ended vertical annulus is analyzed based on a CFD technique. For a vertical annulus, the natural convective heat transfer has a broad application in engineering. The annulus is the most common structure used in various heat transmission systems, from the basic heat transfer device to the most sophisticated atomic reactors. The annular test sections of such a large aspect ratio are of practical importance in the design of equipment's associated with the reactor systems. However, depending on the geometrical structure and heating conditions, it exhibits different flow behavior. The annulus may either be closed or open-ended. In this study, we carry out CFD analysis to examine the thermodynamics properties and the detailed thermal induced flow behavior of the water in Tall open-ended vertical concentric annuli. The purpose of this study is to evaluate the impact of a partially heating on mechanical properties and design parameters like Nusselt number, mass flow rate and pressure defect. For Rayleigh number ranging from 4.4 × 103 to 6.6 × 104, while the Prandtl number is 6.43, the numerical solution was obtained. The modelling result showing the measurement and transient behavior of different parameters is presented. The numerical results would be both qualitatively and quantitatively validated. The presentation of unstable state profiles and heat variables along the annulus are also discussed.