Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
Natural convective heat transfer rates from inclined
cylinders with a circular cross-section and which have an
exposed top surface have been experimentally measured. The
cylinder is mounted on a large flat essentially adiabatic surface
with the other cylinder surfaces exposed to the surrounding air
and with the cylinder, in general, inclined to the vertical at
angles between vertically upwards and vertically downwards.
The diameter-to-height ratio of the cylinders used in the present
study was comparatively small, diameter-to-height ratios of
between 1 and 0.25 being used. The main aim of the present
work was to determine how the diameter-to-height ratio of the
cylinder, i.e., D/h, influences the mean heat transfer rate from
the cylinder at various angles of inclination. The heat transfer
rates were determined by a transient method, which basically
involving heating the model and then measuring its
temperature-time variation while it cooled. Tests were carried
out in air with all models at various angles of inclination to the
vertical of between 0o and 180o. The Rayleigh number, Ra,
based on the cylinder height, h, was between approximately
2E4 and 4E6. The experimental results have been compared
with the results obtained in an earlier numerical study.