diff --git a/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_entry_pressure.md b/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_entry_pressure.md
deleted file mode 100644
index e3d246498cefcd2402e2df304f0047534317a04a..0000000000000000000000000000000000000000
--- a/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_entry_pressure.md
+++ /dev/null
@@ -1 +0,0 @@
-The required pressure for a non-wetting fluid to enter a porous medium (the capillary pressure at full saturation).
diff --git a/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_p_b.md b/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_p_b.md
new file mode 100644
index 0000000000000000000000000000000000000000..e55a5e7dcdb29ee76ffaf545e702492720fed1e3
--- /dev/null
+++ b/Documentation/ProjectFile/properties/property/SaturationVanGenuchten/t_p_b.md
@@ -0,0 +1,9 @@
+Pressure scaling parameter with units of pressure.
+
+Corresponds to van Genuchten parameter \f$\rho g / alpha\f$. The inverse of
+\f$\alpha\f$ "corresponds to the water contents lower then saturation" [1].
+
+[1] van Lier, Quirijn de Jong, and Everton Alves Rodrigues Pinheiro. "An alert
+regarding a common misinterpretation of the van Genuchten α parameter." Revista
+Brasileira de Ciência do Solo 42 (2018).
+
diff --git a/Documentation/bibliography.bib b/Documentation/bibliography.bib
index c246160c435db177450f9e694dfcc3d0eee99dcf..b55ba6ca395453ecc60d59e4f583bdce764912c2 100644
--- a/Documentation/bibliography.bib
+++ b/Documentation/bibliography.bib
@@ -33,6 +33,15 @@
ISBN = {1558607323}
}
+@Article{Genuchten1980,
+ author = "van Genuchten, M. Th.",
+ title = "A closed for equation for predicting the hydraulic conductivity of unsaturated soils",
+ journal = "Soil Sci. Soc.",
+ volume = "44",
+ pages = "892--898",
+ year = "1980"
+}
+
@Article{Kolditz2001,
Title = {{Non-linear flow in fractured rock}},
Author = {Kolditz , Olaf},
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CreateSaturationVanGenuchten.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CreateSaturationVanGenuchten.cpp
index 9b77c416906b13e37db49ca627fa1fcb1c7321e5..b934eef2a24d9a22ee58b12eafe7eef9bae3b9ca 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CreateSaturationVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CreateSaturationVanGenuchten.cpp
@@ -30,12 +30,10 @@ std::unique_ptr<SaturationVanGenuchten> createSaturationVanGenuchten(
auto const exponent =
//! \ogs_file_param{properties__property__SaturationVanGenuchten__exponent}
config.getConfigParameter<double>("exponent");
- auto const entry_pressure =
- //! \ogs_file_param{properties__property__SaturationVanGenuchten__entry_pressure}
- config.getConfigParameter<double>("entry_pressure");
+ //! \ogs_file_param{properties__property__SaturationVanGenuchten__p_b}
+ auto const p_b = config.getConfigParameter<double>("p_b");
- return std::make_unique<SaturationVanGenuchten>(residual_liquid_saturation,
- residual_gas_saturation,
- exponent, entry_pressure);
+ return std::make_unique<SaturationVanGenuchten>(
+ residual_liquid_saturation, residual_gas_saturation, exponent, p_b);
}
} // namespace MaterialPropertyLib
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
index 4a2e23f8c8b12f3b2e85758e20b373916df5c5e6..c87bec41a0feadfcb8b481eba457dda4847e2128 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
@@ -21,11 +21,11 @@ SaturationVanGenuchten::SaturationVanGenuchten(
double const residual_liquid_saturation,
double const residual_gas_saturation,
double const exponent,
- double const entry_pressure)
+ double const p_b)
: _S_L_res(residual_liquid_saturation),
_S_L_max(1. - residual_gas_saturation),
_m(exponent),
- _p_b(entry_pressure)
+ _p_b(p_b)
{
if (!(_m > 0 && _m < 1))
{
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.h b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.h
index 07ffd95c53feaf14a792fbb0a51bedf789d6722d..6590f22b6aeff9bfae8ddbf93d415e5dd11b6b6f 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.h
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.h
@@ -16,40 +16,32 @@ class Medium;
class Phase;
class Component;
/**
- * \brief The van Genuchten capillary pressure model:
+ * \brief The van Genuchten capillary pressure model.
*
- * \f[p_c(S)=p_b (S_e^{-1/m}-1)^{1-m}\f]
- * with
- * \f[S_e=\frac{S-S_r}{S_{\mbox{max}}-S_r}\f]
- * where
- * \f{eqnarray*}{
- * &p_b& \mbox{ entry pressure,}\\
- * &S_r& \mbox{ residual saturation,}\\
- * &S_{\mbox{max}}& \mbox{ maximum saturation,}\\
- * &m \in [0,1) & \mbox{ exponent.}\\
- * \f}
+ * The van Genuchten capillary pressure model (\cite Genuchten1980) is:
+ * \f[p_c(S)=p_b (S_\text{eff}^{-1/m}-1)^{1-m}\f]
+ * with effective saturation defined as
+ * \f[S_\text{eff}=\frac{S-S_r}{S_{\text{max}}-S_r}.\f]
+ * Above, \f$S_r\f$ and \f$S_{\text{max}}\f$ are the residual and the maximum
+ * saturations.
+ * The exponent \f$m \in (0,1)\f$ and the pressure scaling parameter \f$p_b\f$
+ * (it is equal to \f$\rho g/\alpha\f$ in original publication) are given by the
+ * user.
+ * The scaling parameter \f$p_b\f$ is given in same units as pressure.
*
- * Note in some expressions, a parameter of \f$n\f$ is introduced, where
- * \f[n=1/(1-m)\f].
+ * In the original work another exponent \f$n\f$ is used, but usually set to
+ * \f$n = 1 / (1 - m)\f$, and also in this implementation.
*
- * If \f$\alpha\f$ instead of \f$p_b\f$ is available, \f$p_b\f$ can
- * be calculated
- * as
- * \f[p_b=\rho g/\alpha\f].
- *
- * If the capillary pressure is known, the saturation can be
- * obtained by this model with
- * \f[S(p_c)=\left \{
- * \begin{array}{1}
- * S_{\mbox{max}},\, p_c < 0,\\
- * \left( \left(\dfrac{p_c}{p_b}\right)^{\frac{1}{1-m}} +1\right)^{-m}
- * (S_{\mbox{max}}-S_r) +S_r,\, p_c \geq 0
- \end{array}
- * \right.
- * \f].
- *
- * class SaturationVanGenuchten handles the computations associated
- * with \f$S(p_c)\f$.
+ * The saturation is computed from the capillary pressure as follows:
+ * \f[S(p_c)=
+ * \begin{cases}
+ * S_{\text{max}} & \text{for $p_c \leq 0$, and}\\
+ * \left( \left(\frac{p_c}{p_b}\right)^{\frac{1}{1-m}} +1\right)^{-m}
+ * (S_{\text{max}}-S_r) +S_r& \text{for $p_c > 0$.}
+ * \end{cases}
+ * \f]
+ * The result is then clamped between the residual and maximum liquid
+ * saturations.
*/
class SaturationVanGenuchten final : public Property
{
@@ -57,7 +49,7 @@ public:
SaturationVanGenuchten(double const residual_liquid_saturation,
double const residual_gas_saturation,
double const exponent,
- double const entry_pressure);
+ double const p_b);
void setScale(
std::variant<Medium*, Phase*, Component*> scale_pointer) override
diff --git a/Tests/Data/RichardsMechanics/RichardsFlow_2d_quasinewton.prj b/Tests/Data/RichardsMechanics/RichardsFlow_2d_quasinewton.prj
index fc63969a3217dadaf231055ac1646b0b31cf2b86..3c78dca4533eecb643a0ffa71ee6ed43e7dd0b84 100644
--- a/Tests/Data/RichardsMechanics/RichardsFlow_2d_quasinewton.prj
+++ b/Tests/Data/RichardsMechanics/RichardsFlow_2d_quasinewton.prj
@@ -102,7 +102,7 @@
<residual_liquid_saturation>0.1689</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.789029535864979</exponent>
- <entry_pressure>3633.33</entry_pressure>
+ <p_b>3633.33</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/RichardsFlow_2d_richardsflow.prj b/Tests/Data/RichardsMechanics/RichardsFlow_2d_richardsflow.prj
index a0aee9f6e9b80f6efb0e1fad97c6b33a892e9d44..bfa7b667aee4a4d5cb422be54360dbaf99ef5191 100644
--- a/Tests/Data/RichardsMechanics/RichardsFlow_2d_richardsflow.prj
+++ b/Tests/Data/RichardsMechanics/RichardsFlow_2d_richardsflow.prj
@@ -74,7 +74,7 @@
<residual_liquid_saturation>0.1689</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.789029535864979</exponent>
- <entry_pressure>3633.33</entry_pressure>
+ <p_b>3633.33</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/RichardsFlow_2d_small.prj b/Tests/Data/RichardsMechanics/RichardsFlow_2d_small.prj
index c975f69253a9cbff3f8b3f4dc1cdc2969aafffe0..2748a8c620132770fe6ba10579694000e3203acf 100644
--- a/Tests/Data/RichardsMechanics/RichardsFlow_2d_small.prj
+++ b/Tests/Data/RichardsMechanics/RichardsFlow_2d_small.prj
@@ -97,7 +97,7 @@
<residual_liquid_saturation>0.1689</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.789029535864979</exponent>
- <entry_pressure>3633.33</entry_pressure>
+ <p_b>3633.33</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/RichardsFlow_2d_small_masslumping.prj b/Tests/Data/RichardsMechanics/RichardsFlow_2d_small_masslumping.prj
index 5c0be74da6b75219723dd5ff7a7c6694ebee1612..6aecc0738522a2a186cd367982e8262463960eab 100644
--- a/Tests/Data/RichardsMechanics/RichardsFlow_2d_small_masslumping.prj
+++ b/Tests/Data/RichardsMechanics/RichardsFlow_2d_small_masslumping.prj
@@ -98,7 +98,7 @@
<residual_liquid_saturation>0.1689</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.789029535864979</exponent>
- <entry_pressure>3633.33</entry_pressure>
+ <p_b>3633.33</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/bishops_effective_stress_power_law.prj b/Tests/Data/RichardsMechanics/bishops_effective_stress_power_law.prj
index 6e1ec61b27ab8ec280ff96dfc227bb413ec69816..d9f345edca52924ca790a630c4d97d3a6e818dff 100644
--- a/Tests/Data/RichardsMechanics/bishops_effective_stress_power_law.prj
+++ b/Tests/Data/RichardsMechanics/bishops_effective_stress_power_law.prj
@@ -100,7 +100,7 @@
<residual_liquid_saturation>0.1</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.8</exponent>
- <entry_pressure>0.5</entry_pressure>
+ <p_b>0.5</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/bishops_effective_stress_saturation_cutoff.prj b/Tests/Data/RichardsMechanics/bishops_effective_stress_saturation_cutoff.prj
index fe65fa784251bf5070761b66459f363cb14d0688..38453948e5b2aaa75fd2fd3803be4a6a8faa46c0 100644
--- a/Tests/Data/RichardsMechanics/bishops_effective_stress_saturation_cutoff.prj
+++ b/Tests/Data/RichardsMechanics/bishops_effective_stress_saturation_cutoff.prj
@@ -100,7 +100,7 @@
<residual_liquid_saturation>0.1</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.8</exponent>
- <entry_pressure>0.5</entry_pressure>
+ <p_b>0.5</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/deformation_dependent_porosity_swelling.prj b/Tests/Data/RichardsMechanics/deformation_dependent_porosity_swelling.prj
index 6302782ebfff3e3822fb77f2a9b147931ef6da52..0656d2fbc04b3ce30a3ab448668955cabbccb4b6 100644
--- a/Tests/Data/RichardsMechanics/deformation_dependent_porosity_swelling.prj
+++ b/Tests/Data/RichardsMechanics/deformation_dependent_porosity_swelling.prj
@@ -117,7 +117,7 @@
<residual_liquid_saturation>0.1</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.8</exponent>
- <entry_pressure>0.5</entry_pressure>
+ <p_b>0.5</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/gravity.prj b/Tests/Data/RichardsMechanics/gravity.prj
index 5b3c0037cf93b9ac656603ec94351bd6a53e782e..d79597a3a856a8fd6bf41abc0d147b332b256628 100644
--- a/Tests/Data/RichardsMechanics/gravity.prj
+++ b/Tests/Data/RichardsMechanics/gravity.prj
@@ -104,7 +104,7 @@
<residual_liquid_saturation>0.01</residual_liquid_saturation>
<residual_gas_saturation>0.01</residual_gas_saturation>
<exponent>0.789029535864979</exponent>
- <entry_pressure>3633.33</entry_pressure>
+ <p_b>3633.33</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/orthotropic_swelling_xy.prj b/Tests/Data/RichardsMechanics/orthotropic_swelling_xy.prj
index 30dbec1c3bab7d7815eb80530c2f08fba13e7c59..3e453dbde73146bc0a10248ab6500688a89580e8 100644
--- a/Tests/Data/RichardsMechanics/orthotropic_swelling_xy.prj
+++ b/Tests/Data/RichardsMechanics/orthotropic_swelling_xy.prj
@@ -109,7 +109,7 @@
<residual_liquid_saturation>0.1</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.8</exponent>
- <entry_pressure>0.5</entry_pressure>
+ <p_b>0.5</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/Data/RichardsMechanics/orthotropic_swelling_xyz.prj b/Tests/Data/RichardsMechanics/orthotropic_swelling_xyz.prj
index 04867c4c4dd71725700910ce1ab6eb8b9202714c..46a23e631918a58b3e910527a8142afba977ebc5 100644
--- a/Tests/Data/RichardsMechanics/orthotropic_swelling_xyz.prj
+++ b/Tests/Data/RichardsMechanics/orthotropic_swelling_xyz.prj
@@ -109,7 +109,7 @@
<residual_liquid_saturation>0.1</residual_liquid_saturation>
<residual_gas_saturation>0.05</residual_gas_saturation>
<exponent>0.8</exponent>
- <entry_pressure>0.5</entry_pressure>
+ <p_b>0.5</p_b>
</property>
<property>
<name>relative_permeability</name>
diff --git a/Tests/MaterialLib/TestMPLSaturationVanGenuchten.cpp b/Tests/MaterialLib/TestMPLSaturationVanGenuchten.cpp
index 824f1b84742850c7a0b05bed134951b076091d81..84ce6210f545f6595ac9cabeea9e712c65e7c11c 100644
--- a/Tests/MaterialLib/TestMPLSaturationVanGenuchten.cpp
+++ b/Tests/MaterialLib/TestMPLSaturationVanGenuchten.cpp
@@ -21,11 +21,10 @@ TEST(MaterialPropertyLib, SaturationVanGenuchten)
double const residual_liquid_saturation = 0.1;
double const residual_gas_saturation = 0.05;
double const exponent = 0.79;
- double const entry_pressure = 5000;
+ double const p_b = 5000;
MPL::Property const& pressure_saturation = MPL::SaturationVanGenuchten{
- residual_liquid_saturation, residual_gas_saturation, exponent,
- entry_pressure};
+ residual_liquid_saturation, residual_gas_saturation, exponent, p_b};
MPL::VariableArray variable_array;
ParameterLib::SpatialPosition const pos;