Paper presented to the 1st International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Kruger Park 8-10 April 2002.
The geometric shape of a passage's cross-section has an
effect on its convective heat transfer capabilities. For
concentric annuli, as cross section, the diameter ratio of the
annular space plays an important role. The purpose of this
investigation was to find a correlation that will accurately
predict heat transfer coefficients at the inner wall of smooth
concentric annuli for the flow of water. Experiments were
conducted on water under turbulent flow conditions for a wide
range of diameter ratios. The Wilson plot method was used to
determine the heat transfer coefficients from which a
correlation was developed that could be used to predict the
heat transfer coefficients.
It was found that the correlation predicted Nusselt
numbers accurately within 3% of measured values for
diameter ratios between a= 1.7 and a= 5.1 and a Reynolds
numbers range of 4 000 to 30 000.