DOI: 10.1615/ICHMT.2008.CHT
ISBN Print: 978-1-56700-253-9
ISSN: 2578-5486
THE INFLUENCE OF THERMAL CONDUCTIVITY ON THE HEAT TRANSFER BETWEEN A CYLINDER AND ASCENDING FLUID
要約
This paper concerns the numerical study of the effect of thermal conductivity of an incompressible Newtonian fluid flow in a vertical duct. The ascendant fluid flows around a heated cylindrical obstacle, which is placed in a fixed distance from the inlet. In this work we try to explore the effects of thermal conductivity on the heat transfer between the cylinder and the moving fluid. Thereby, different kinds of fluid have been considered in this work. The taken assumptions and the choice of the numerical method have limited the variation interval of the Prandtl number between 0.1 and 2. The governing equations representing the dynamic and thermal phenomenon are those deduced from mass, momentum and energy conservation equations. The numerical resolution of the system is based on an implicit scheme of finite differences, in velocity-pressure formulation. The grid is based on the cell configuration of MAC. The results show that the impact of Prandtl number on the thermal transfer is very important and that when the flow is performed in small Reynolds number, the fluid layers are less heated as the Prandtl number increases. And that when the Prandtl number is greater than unity, the Nusselt number profile presents an inflexion point for Reynolds number Re=250 because of the thermal instability appearance.