THERMAL CONDUCTIVITY OF MOLTEN MATERIALS. IS EXPERIMENT NECESSARY?
C. A. Nieto de Castro
Abstract:
The knowledge on the thermal conductivity of molten materials (salts, metals, semiconductors, polymers) is very scarce, both from the experimental and theoretical points of view. Knowing of the difficulty in obtaining accurate experimental data for most liquids, the task is uncouthly more difficult when the measurements are to be performed at medium and high temperatures with materials that are corrosive, easily reacting and good heat transfer media. Convective and radiative heat transfer effects affect in particular thermal conductivity measurements at high temperatures. These facts also make difficult theoretical calculations using molecular/ionic theories and drastic approximations, both from the phenomenological side, to the force field between particles, restrict the validity of the results obtained. Computer simulations are a possible alternative to overcome these problems and its development in recent years is noteworthy, induced by the improvements in theory, algorithms and computer hardware. Their applications to the study of molten materials have been very limited and with results of questionable validity. However, it was recently possible to apply equilibrium molecular dynamics simulations to the calculation molten salts thermal conductivity with a reasonable success. In this lecture a short review of the field will be presented, with especially emphasis in the actual situation, challenges faced and foreseen solutions, including microgravity experiments.
