Relation for the saturation-dependent effective thermal conductivity. More...
#include <dumux/material/fluidmatrixinteractions/2p/thermalconductivity/johansen.hh>
Relation for the saturation-dependent effective thermal conductivity.
The Johansen method (Johansen 1975 [35] ) computes the thermal conductivity of dry and the wet soil material and uses a root function of the wetting saturation to compute the effective thermal conductivity for a two-phase fluidsystem. The individual thermal conductivities are calculated as geometric mean of the thermal conductivity of the porous material and of the respective fluid phase. The material law is: \(\mathrm{[ \lambda_\text{eff} = \lambda_{\text{dry}} + \sqrt{(S_w)} \left(\lambda_\text{wet} - \lambda_\text{dry}\right) }\)
with \(\mathrm{ \lambda_\text{wet} = \lambda_{solid}^{\left(1-\phi\right)}*\lambda_w^\phi }\) and the semi-empirical relation
\(\mathrm{ \lambda_\text{dry} = \frac{0.135*\rho_s*\phi + 64.7}{\rho_s - 0.947 \rho_s*\phi}. }\)
Source: Phdthesis (Johansen1975) Johansen, O. Thermal conductivity of soils Norw. Univ. of Sci. Technol., Trondheim, Norway, 1975 [35]
Static Public Member Functions | |
template<class VolumeVariables > | |
static Scalar | effectiveThermalConductivity (const VolumeVariables &volVars) |
Returns the effective thermal conductivity \(\mathrm{[W/(m K)]}\) after Johansen (1975) [35] . More... | |
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inlinestatic |
Returns the effective thermal conductivity \(\mathrm{[W/(m K)]}\) after Johansen (1975) [35] .
volVars | volume variables |
This formulation is semi-empirical and fitted to quartz sand. This gives an interpolation of the effective thermal conductivities of a porous medium filled with the nonwetting phase and a porous medium filled with the wetting phase. These two effective conductivities are computed as geometric mean of the solid and the fluid conductivities and interpolated with the Kersten number.
Johansen, O. 1975. Thermal conductivity of soils. Ph.D. diss. Norwegian Univ. of Sci. and Technol., Trondheim. (Draft Transl. 637. 1977. U.S. Army Corps of Eng., Cold Regions Res. and Eng. Lab., Hanover, NH.) [35]