Experimental investigation of turbulent heat transfer to liquid sodium in the thermal entrance regions of an annulus

An experimental investigation was performed for turbulent heat transfer to liquid sodium in the thermal fully developed region with a constant heat flux in the inner wall of an annulus and an adiabatic condition in its outer wall. The measurements were carried out over a range of the Reynolds numbers from 20000 to 150000 for a Prandtl number of 0.007. The inner and outer diameter of the channel were respectively 12.34 mm and 19.00 mm. The velocity profile was fully developed at the beginning of heating. It was found that the experimental results were in good agreement with the other previously reported results. Finally, some empirical relations were obtained for the heat transfer both in the fully developed region and in the entrance region. (orig.)