An experimental and numerical investigation of natural convection plumes above a horizontal cylinder in an isothermal cubical enclosure

A comparison is presented between the predicted and measured temperature and velocity fields above a horizontal cylinder in natural convection. This is repeated for a second cylinder operating at the same Grashof number to confirm the non-dimensional scaling. The cylinders were centred in an isothermal cubical enclosure with water cooled walls. Measurements were made with hot wires operating in the constant temperature and constant current modes. A description of the calibration process is presented. These measurements give some details on the oscillation of the plume. The numerical predictions are from a computational package that is widely used in the electronics industry. The plumes are generally well-predicted, with some of the differences between prediction and measurement attributed to the sensitivity of the measured plume to the boundary conditions.