Experimental Analyses of Natural Convection and Radiation Heat Transfer from a Horizontal Cylinder
Steady-state natural convection and radiation heat transfer from a horizontal cylinder dissipating uniform heat flux in air is investigated. In the vertical outlet duct, a surface heat transfer distribution on the circumference of the cylinder is presented for Rayleigh number, 2×103 RaD 2×104. The heat flux ranges from 20 W/m2 to 500 W/m2. The effects of heat transfer around the cylinder under natural convection and radiation heat transfers are investigated. It is documented that the radiation heat transfer is the important part of total heat transfer and contributes 1/3 of convection heat transfer. The results compare favorably with those obtained from the literature. Finally, the dependence of the average Nusselt number on Rayleigh number is analyzed and a correlation equation is presented, as NuD = 0.693RaD0.256.