Engineering Science and Technology, an International Journal (Mar 2022)
The effects of the cross-section shape of the surface-mounted cylinder on the free convective junction flow
Abstract
The present study numerically describes the nature of the arising boundary layer along an isothermal vertical plate, on which is mounted a bluff body. The investigation parameter is the cross-section shape of the bluff body, which includes a square, circular, and prismatic cylinders. To entirely embedded cylinder in the incoming boundary layer, the simulations include short cylinders with an aspect ratio fixed to unity. The cylinder location related to the leading edge of the plate is identified by considering laminar Grashof number, which experimentally is investigated in parallel work. Besides this, the experimental study of a square cylinder, confirms the reliability and accuracy of numerical simulation. As a result, by providing steady-state simulation, the presence of a complex vortex structure is proved. Besides, the effects of the cross-section shape of the cylinder on the dynamics characteristics of the vortex system include vorticity strength, size, and position are categorized. Finally, the significant effects of formed juncture flow on the three-dimensional thermal characteristics of arising free convective boundary layers along with the heated vertical plate are emphasized by a description of heat transfer coefficients. In particular, the importance of the frontal bluntness of cylinder in the field of thermal management is claimed, where the maximum value of the heat transfer coefficient for circular, prismatic, and square cylinders, respectively appears at the angular coordinates of0, 45, and 90 degrees, which correspond with the location of cylinder edges.
