Abstract
An experimental investigation of the heat transfer in annular fins of constant thickness was carried out to prove the total resistance model suggested by Kahwaji [4] , given in equation (1) in the introduction . The experiments covered both the natural convection and forced convection heat transfer modes using fins of different materials and dimensions. Different Ra and Re numbers also achieved through varying the power input to the fins and the speed of the air flowing through the fin assembly. The results indicated good agreement between the suggested model and the experimental findings. Calculated and measured heat flux was found to be less than (8.33%) in the natural convection tests and (11%) in the forced convection tests. The maximum experimental error was estimated at about (6.33%). A numerical solution, based on the Gauss-siedel technique, was also derived and used to support the results.
Key words: Heat transfer, annular fin, natural and forced convection, heat
transfer coefficient
