BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Thermal conductivity surface of argon: A fresh analysis

Participants in the publication
R. A. Perkins (Author)
D. G. Friend (Author)
H. M. Roder (Author)
C. A. Nieto de Castro (Author)
Dep. Química e Bioquímica
CQE

Summary
This paper presents a fresh analysis of the thermal conductivity surface of argon at temperatures between 100 and 325 K with pressures up to 70 MPa. The new analysis is justified for several reasons. First, we discovered an error in the compression-work correction, which is applied when calculating thermal conductivity and thermal diffusivity obtained with the transient hot-wire technique. The effect of the error is limited to low densities, i.e., for argon below 5 mol·L−1. The error in question centers on the volume of fluid exposed to compression work. Once corrected, the low-density data agree very well with the available theory for both dilute-gas thermal conductivity and the first density coefficient of thermal conductivity. Further, the corrected low-density data, if used in conjunction with our previously reported data for the liquid and supercritical dense-gas phases, allow us to represent the thermal conductivity in the critical region with a recently developed mode-coupling theory. Thus the new surface incorporates theoretically based expressions for the dilute-gas thermal conductivity, the first density coefficient, and the critical enhancement. The new surface exhibits a significant reduction in overall error compared to our previous surface which was entirely empirical. The uncertainty in the new thermal conductivity surface is ±2.2% at the 95% confidence level.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
International Journal of Thermophysics

Publication Identifiers

Publisher
Springer Science and Business Media LLC



Document Identifiers
DOI - https://doi.org/10.1007/bf00503513
URL - http://dx.doi.org/10.1007/bf00503513

Keywords
argon liquid supercritical surface fit thermal conductivity transient hot wire technique vapor

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