A study of natural convection heat transfer in a maximum eccentric horizontal annulus

A steady state laminar natural convection heat transfer in a maximum eccentric (epsilon=1) horizontal annulus with different diameter ratios and three eccentric positions of the top, the bottom and the side have been investigated by both experiments and numerical analysis. Four models with radii Ratios from 1.3 to 3.8 and Ra number from 4.6x10(2) to 6x10(5) were tested, and the correlating equation from those experiments was reported. The tangent circles coordinate system and its transformation were applied to the numerical simulations for the special physical boundary. Both the two-dimension temperature distributions obtained from numerical analysis and the interferogram of experiments were presented for comparison, and they are coincident correspondingly. The local film heat transfer coefficients and heat flux on both inner and outer walls obtained by the numerical simulations are also presented. The ranges of the parameters concerned in the numerical analysis are 2.0x10(2) less than or equal to Ra less than or equal to 3.0x10(5), and 1.3 less than or equal to Do / D i less than or equal to 3.8.