Natural convection inside a horizontal cylinder

Abstract

The two vertical halves of the wall of a 4.3-in. I.D. cylinder were maintained at different uniform temperatures. The rate of circulation of air inside the cylinder and the local rate of heat transfer between the wall and air were derived from measurements of the velocity and temperature fields in the air for wall-temperature differences from 3.5° to 367°F. The overall rate of circulation was found to increase quite rapidly and then to decrease slowly as the wall-temperature difference was increased. The over-all Nusselt number based on the wall-temperature difference was found to have an approximately constant value of 7.0. Numerical solution of the partial differential equations describing the conservation of mass, momentum, and energy for this system was investigated with an IBM-650 magnetic drum computer. Instabilities in the computational procedure and limitations of this computer prevented solution of the general problem. However specification of the velocity field obtained from experiment yielded a numerical solution for the temperature field in good agreement with the experimental measurements.