EXPERIMENTAL INVESTIGATION OF ORIENTATION EFFECTS ON HEATED CYLINDER WITH DIFFERENT DIAMETERS INSIDE A SQUARE-SECTION SHIELD

الملخص

In this paper, an experimental investigation has been done for laminar steady-state free-convection heat transfer from a heated hollow cylinder to ambient air inside an open-ended square-section shield with orientation and cylinder diameter effects. Four aluminum heated cylinders of different diameters are employed. The cylinders are heated with various supplied power levels. Six inclinations of a heated cylinder with the vertical position, namely 0^o, 15^o, 30^o, 45^o, 60^o, and 75^o are used. The effects of orientation on local surface temperatures profile along with the heated cylinder, convection heat transfer coefficient, Nusselt number, and Rayleigh number at different diameters and heat inputs to the heating element have been plotted and explained. The experimental results show that the local heat transfer coefficient is maximum at an inclination angle of 75^o and at the cylinder base. The present experimental results are compared with previous works shows good agreement.