Entropy Analysis of Heat Transfer in Solid Torus with Isothermal Boundary Conditions

This paper examines the entropy generation in a vertically placed solid torus in the vicinity of natural convection using numerical method. The study was performed by exercising the variation in parameters such as the aspect ratio of the solid torus (2.5–7.5), surface temperature of the solid torus ranging between 375 and 600 K, and Rayleigh number ranging between [Formula: see text] for laminar flow. The study analyzes the effect of all these variables on convective heat transfer, airflow dynamics, and generation of entropy. The outcomes indicate that with an elevated Rayleigh number, a higher aspect ratio experiences an accelerated rate of heat loss but with a reduced pace. For a constant Rayleigh number and dimensionless surface temperature, with increment in the aspect ratio from 2.5 to 5, the value of nondimensional heat transfer strengthens by around 80% but it reduces by about 50% when the aspect ratio upsurges from 5 to 7.5. The production of entropy intensifies by approximately 1.5 times with a rise in Rayleigh number for a specified aspect ratio and surface temperature. Furthermore, the degree of irreversibility on the account of heat transfer is considerably higher than irreversibility caused by fluid friction and contributes a vital role in the production of entropy generation. The deviations encountered during the investigation are quantitively and pictorially presented for the entire parametric variations to provide a deeper understanding. These findings will provide a better insight for the industrial engineers dealing with the thermal management of the toroidal- shaped objects.