Abstract
An analysis of soil thermal conductivity data shows that, at very low moisture content, this property first varies insignificantly and then begins to increase from a certain critical moisture content, whose value tends to depend on clay mass fraction. Two simple models evaluating the critical moisture content were developed; the first one is a fraction of the permanent wilting point; the second one is a simple linear function dependent on clay mass fraction. An insignificant variation of soil thermal conductivity is observed at 20°C, within a water pressure head ranging from 1 × 103 to 1 × 103 m, while for higher temperatures (45–50°C) from 5000 to 100000 m. Three extensions of the enhanced thermal conductivity model by Sundberg, namely SUN-1, SUN-2 and SUN-3, were proposed and tested. They produce an average root mean square error of 27%, 24% and 30%, respectively, with respect to experimental data. SUN-1and SUN-2 predictions could be further improved if better estimates of thermal conductivity at the dry state and the permanent wilting point were provided. SUN-3 is a simple model which does not require information about the PWP and critical moisture content. All SUN models have a potential for implementing the latent heat transfer component.
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References
Bruggeman, D. A. G.: 1935, Calculation of various physical properties of heterogeneous substances, Annalen der Physik 24, 636–679 (in German).
Campbell, G. S., Jungbauer, J. D., Bidlake, W. R. and Hungerford, R. D.: 1994, Predicting the effect of temperature on soil thermal conductivity, Soil Sci. 158(5), 307–313.
Gori, F.: 1983, A theoretical model for predicting the effective thermal conductivity of unsaturated frozen soils, In: Proc. of the 4th International Conference on Permafrost, Fairbanks (Alaska), National Academy Press, Washington, D.C, pp. 363–368.
Johansen, O.: 1975, Thermal conductivity of soils, PhD Thesis, Trondheim, Norway (CRREL draft translation 637, 1977).
Kersten, M. S.: 1949, Thermal Properties of Soils, University of Minnesota, Institute of Technology, Bull. No. 28, pp. 1–226.
McInnes, K.: 1981, Thermal conductivities of soils from dryland wheat regions in Easter Washington. MSc thesis, Washington State University.
Nakshabandi, G. A. and Konke, H.: 1965, Thermal conductivity and diffusivity of soils as related to moisture tension and other physical properties, Agric. Meteorol. 2, 271–279.
Rawls, W. J., Brakensiek, D. L. and Saxton, K. E.: 1982, Estimation of soil water properties, Trans. ASAE 25, 1316–1320, 1328.
Sepaskhah, A. R. and Boersma, L.: 1979, Thermal conductivity of soils as a function of temperature and water content, Soil Sci. Soc. Am. J. 43, 439–444.
Smith, W. O.: 1939, Thermal conductivities in moist soils, Soil Sci. Soc. Am. Proc. 193(4), 32–40.
Sundberg, J.: 1988, Thermal properties of soils and rocks, Geologiska Institutionen A57, 1–310.
Tarnawski, V. R., Gori, F., Wagner, B. and Buchan, G. D.: 2000, Modeling approaches to predicting thermal conductivity of soils at high temperatures. Int. J. Energy Res. 24, 403–423.
De Vries, D. A.: 1963, Thermal properties of soils, In: W. R. van Wijk (ed.), Physics of Plant Environment, North-Holland Publishing Company, Amsterdam, pp. 210–235.
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Tarnawski, VR., Leong, W.H. Thermal Conductivity of Soils at Very Low Moisture Content and Moderate Temperatures. Transport in Porous Media 41, 137–147 (2000). https://doi.org/10.1023/A:1006738727206
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DOI: https://doi.org/10.1023/A:1006738727206