Investigation of convective heat transfer in ducts of polygon shapes

Abstract

Natural convection heat transfer is a wide topic that is relevant in a lot of applications, those being industrial, environmental or others. This topic investigates the outcome of placing a hot entity inside an enclosure that is colder. These temperature differences induce some local density gradients and buoyancy effects that drive the flow of the fluid present inside the enclosure. In this study, the effects of the geometry and position of the inner cylinder for a specific aspect ratio are studied. The inner cylinder is taken to be as a polygon with number of sides varying between 3 and 10. The simulations are conducted for a Rayleigh number varying between 103 and 106. The fluid flow is more apparent for higher Rayleigh, where the heat transfer regime becomes more convective. In order to analyze these phenomena, results are presented in terms of isotherms and streamlines. Local and average Nusselt numbers are also investigated.