Thermal conductivity measurement and numerical simulation of melts under non-uniform temperature fields

Abstract Accurate thermal conductivity measurement of high-temperature melts under non-uniform thermal fields remains a critical challenge for space materials science. This study presents an integrated experimental-numerical approach combining a customized single-wire probe (withstanding 5 g vibrations) with computational fluid dynamics (CFD)-based inversion to address this fundamental limitation. Through systematic ground-based verification, the method demonstrates exceptional performance: for liquid water, at a representative current of 1.8 A, CFD-based inversion reduces the deviation from the reference value from 1.87% to 0.62%; for molten indium, it identifies an optimal thermal conductivity of approximately 37 W (m · K) −1 , which is consistent with the literature reference within the expanded uncertainty. This represents a significant reduction in systematic deviation compared with conventional uncorrected results. The comprehensive uncertainty analysis yields relative expanded uncertainties of 6.2% for water and 5.3% for indium, providing confidence intervals for the measurements.