INTERFEROMETRIC INVESTIGATIONS OF CONVECTION AROUND CYLINDERS AT SMALL GRASHOF NUMBERS

Experiments with a Twyman-Green interferometer have been carried out to determine the temperature distribution around a horizontal cylinder in the presence of natural convection for Grashof numbers around 10-4 and a Prandtl number of 0.7, a region of parameters poorly covered by previous investigations. Temperature differences are recovered by digital analysis of the fringe pattern perturbation. The results indicate significant discrepancies in the temperature profile, when compared with numerical models