Heat transfer in a liquid metal crucible with an integral blackbody cavity.

摘要

Calculations of the heat transfer in a liquid metal crucible with an integral blackbody cavity have been made using two- and three-dimensional finite element techniques. Computations of thermal gradients and radiant heat exchange out of the cavity are combined to estimate cavity apparent emissivity (or quality) in a total hemispherical sense. We adjusted the model to estimate quality in a normal total sense, and then we used the Planck function to estimate normal spectral quality over the wavelength range 0.4 to 10 (mu)m. Because of the small cavity size, its proximity to the crucible's heat source, and the conductivity of the crucible material, the estimated cavity quality is high, >98% . The crucible design analyzed here was employed in an apparatus for the measurement of the normal spectral emissivity and optical constants of liquid uranium and aluminum. We found the results to be conservative.