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

Abstract

In this paper, experimental investigation has been done for laminar steady-state free-convection heat transfer from 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 heated cylinder with the vertical position, namely 0o, 15o, 30o, 45o, 60o and 75o are used . The effects of orientation on local surface temperatures profile along 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 inclination angle 75o and at cylinder base .The present experimental results is compared with previously works shows the good agreement .