Effects of Corner Modifications on Flow and Heat Transfer in Square Cylinders

Abstract

Fluid flow and heat transfer around a bluff body is an important research area in many engineering fields. Some of the practical examples are heat losses from high-rise buildings, cooling towers, chimneys, power generators, heat exchangers, cooling of electronic systems, flow around nuclear rods etc. In the present investigation flow past a single heated square cylinder with and without corner modifications is being numerically investigated. For sharp-Cornered Square Cylinder, flow separation occurs sharply at the corners, leading to a broad wake and prominent vortex shedding, particularly at higher Reynolds numbers. The pressure distribution shows a sharp drop near the corners, and both lift and drag oscillations intensify with increasing Reynolds number.The oscillations in lift and drag coefficients are larger due to more intense vortex shedding, contributing to high aerodynamic forces.Heat transfer, indicated by the Nusselt number, is less efficient compared to cylinders with corner modifications.In case of Chamfered-Cornered Square Cylinder,Chamfering reduces the bluffness of the cylinder, resulting in smoother flow separation, narrower wakes, and more stable vortex dynamics.Pressure force and oscillations in lift and drag coefficients are moderate compared to the sharp-cornered case.The Nusselt number is more uniform around the cylinder, but still lower than for the rounded corners.But in Rounded-Cornered Square Cylinder,Rounded corners significantly delay flow separation, leading to a narrow wake and reduced vortex shedding intensity.Pressure variations are smoother, and both lift and drag forces are more stable compared to sharp and chamfered corners.Heat transfer is most efficient in the rounded-corner configuration, as reflected by the higher Nusselt number, especially at higher Reynolds numbers.