Variation in the angular heat flux of the oxide pool with Rayleigh number

The experiments were performed on natural convection heat transfer of an oxide pool using a three-dimensional hemispheric test rig. To achieve a high Ra, mass transfer experiments were conducted based on the analogy between heat and mass transfers. A CuSO4-H2SO4 electroplating system was used. The range of modified Ra was from 8.63 × 1012 to 1.45 × 1015 with a cooling top plate and from 2.44 × 1012 to 4.73 × 1014 with an insulating top plate. The Sc was 2014. The mean and local Nu values of the lower head and top plate were measured and compared with previous reports. The total Nu values agreed well with existing studies, within 10%. The split ratio of the heat fluxes between the lower head and top plate was affected by the difference in the Pr. Heat flux distributions at the lower head and top plate were not affected significantly by the modified Ra, except for the uppermost location of the lower head. The heat flux distribution at the lower head was not affected by the top cooling condition. Heat transfer correlations for mean and local Nu values were developed from the experimental results.