diff --git a/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.cpp b/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.cpp
index 94f66033439cc06eba9c44b248d4868375564c55..b9488d5ba74c2a53ddc7e787ea4c5a2dc92f54a0 100644
--- a/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.cpp
+++ b/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.cpp
@@ -25,17 +25,12 @@ PropertyDataType VapourDiffusionFEBEX::value(
const ParameterLib::SpatialPosition& /*pos*/, const double /*t*/,
const double /*dt*/) const
{
- const double S_L = std::clamp(variable_array.liquid_saturation, 0.0, 1.0);
-
const double T = variable_array.temperature;
- const double phi = variable_array.porosity;
-
- const double D_vr = tortuosity_ * phi * (1 - S_L);
return 2.16e-5 *
std::pow(T / MaterialLib::PhysicalConstant::CelsiusZeroInKelvin,
1.8) *
- D_vr;
+ tortuosity_;
}
PropertyDataType VapourDiffusionFEBEX::dValue(
@@ -43,26 +38,18 @@ PropertyDataType VapourDiffusionFEBEX::dValue(
ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
double const /*dt*/) const
{
- const double S_L = std::clamp(variable_array.liquid_saturation, 0.0, 1.0);
-
const double T = variable_array.temperature;
- const double phi = variable_array.porosity;
if (variable == Variable::temperature)
{
- const double D_vr = tortuosity_ * phi * (1 - S_L);
-
return 1.8 * 2.16e-5 *
std::pow(T / MaterialLib::PhysicalConstant::CelsiusZeroInKelvin,
0.8) *
- D_vr / MaterialLib::PhysicalConstant::CelsiusZeroInKelvin;
+ tortuosity_ / MaterialLib::PhysicalConstant::CelsiusZeroInKelvin;
}
if (variable == Variable::liquid_saturation)
{
- return -2.16e-5 *
- std::pow(T / MaterialLib::PhysicalConstant::CelsiusZeroInKelvin,
- 1.8) *
- tortuosity_ * phi;
+ return 0.0;
}
OGS_FATAL(
diff --git a/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.h b/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.h
index 7e015c2d49b8773fc8e7b9eeef108ed541fb437a..b52f6fd958ad8657945c3499d3937970b103a1fa 100644
--- a/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.h
+++ b/MaterialLib/MPL/Properties/VapourDiffusion/VapourDiffusionFEBEX.h
@@ -34,11 +34,15 @@ class Phase;
*
* In the FEBEX type, \f$D_{vr}\f$ takes the form of \cite Rutquist2007TaskA1
* \f[
- * D_{vr}=\tau \phi (1 - S ),
+ * D_{vr}=\tau \phi (1-S_L),
* \f]
- * with \f$\phi\f$, the porosity, \f$S\f$, the water saturation,
- * and \f$\tau\f$ the tortuosity.
+ * with \f$\phi\f$, the porosity, \f$S_L\f$, the liquid saturation,
+ * and \f$\tau\f$, the tortuosity.
*
+ * Note: In order to maintain consistency with the implementation of the
+ * computations of other vapor-related parameters, \f$ \phi (1 - S_L )\f$ is
+ * removed from the implementation for this class and is multiplied back in
+ * the local assembler.
*/
class VapourDiffusionFEBEX final : public Property
{
diff --git a/Tests/MaterialLib/TestMPLVapourDiffusionFEBEX.cpp b/Tests/MaterialLib/TestMPLVapourDiffusionFEBEX.cpp
index 8bdabb4691b5d818733a4142d617d0cf18aefe84..011bd7536a05a114d835c6bf02310a0debed43d1 100644
--- a/Tests/MaterialLib/TestMPLVapourDiffusionFEBEX.cpp
+++ b/Tests/MaterialLib/TestMPLVapourDiffusionFEBEX.cpp
@@ -33,23 +33,18 @@ TEST(MaterialPropertyLib, VapourDiffusionFEBEX)
MaterialPropertyLib::Property const& property = *property_ptr;
double const T = 290.0;
- double const S = 0.5;
- double const phi = 0.15;
MaterialPropertyLib::VariableArray variable_array;
ParameterLib::SpatialPosition const pos;
double const t = std::numeric_limits<double>::quiet_NaN();
double const dt = std::numeric_limits<double>::quiet_NaN();
variable_array.temperature = T;
- variable_array.liquid_saturation = S;
- variable_array.porosity = phi;
// The derivative of the water vapour with respect of temperature
{
std::array const Ts = {273.0, 293.0, 393.0, 420.0, 500.0};
- std::array const D_v_expected = {1.294719e-06, 1.470431e-06,
- 2.494534e-06, 2.811458e-06,
- 3.847945e-06};
+ std::array const D_v_expected = {1.72629e-05, 1.96057e-05, 3.32605e-05,
+ 3.74861e-05, 5.13059e-05, 1.92459e-05};
for (std::size_t i = 0; i < Ts.size(); ++i)
{
@@ -86,62 +81,32 @@ TEST(MaterialPropertyLib, VapourDiffusionFEBEX)
<< analytic_dDv_dT;
}
}
- // The derivative of the water vapour with respect of saturation
+ // The derivative of the water vapour with respect of saturation, which is
+ // zero.
{
std::array const S = {-1.0, 0.0, 0.2, 0.33, 0.45,
0.52, 0.6, 0.85, 1.0, 1.1};
- std::array const D_v_expected = {
- 2.886883e-06, 2.886883e-06, 2.309507e-06, 1.934212e-06,
- 1.587786e-06, 1.385704e-06, 1.154753e-06, 4.330325e-07,
- 0.000000e+00, 0.000000e+00};
+ double const D_v_expected = 1.92459e-05;
for (std::size_t i = 0; i < S.size(); ++i)
{
variable_array.temperature = T;
- double const S_L_i = S[i];
- variable_array.liquid_saturation = S_L_i;
double const D_v =
property.template value<double>(variable_array, pos, t, dt);
- ASSERT_LE(std::fabs(D_v_expected[i] - D_v), 1e-10)
- << "for expected water vapour diffusion " << D_v_expected[i]
+ ASSERT_LE(std::fabs(D_v_expected - D_v), 1e-10)
+ << "for expected water vapour diffusion " << D_v_expected
<< " and for computed water vapour diffusion " << D_v;
double const analytic_dDv_dS = property.template dValue<double>(
variable_array, MPL::Variable::liquid_saturation, pos, t, dt);
- double const dS_L = 1e-8;
- double S_L_a = S_L_i - dS_L;
- double S_L_b = S_L_i + dS_L;
- double factor = 0.5;
-
- if (S_L_i <= 0.0)
- {
- S_L_a = S_L_i;
- S_L_b = dS_L;
- factor = 1.0;
- }
- else if (S_L_i >= 1.0)
- {
- S_L_a = 1.0 - dS_L;
- S_L_b = S_L_i;
- factor = 1.0;
- }
-
- variable_array.liquid_saturation = S_L_a;
- double const D_v_a =
- property.template value<double>(variable_array, pos, t, dt);
- variable_array.liquid_saturation = S_L_b;
- double const D_v_b =
- property.template value<double>(variable_array, pos, t, dt);
- double const approximated_dDv_dS = factor * (D_v_b - D_v_a) / dS_L;
+ double const expected_dDv_dS = 0.0;
- ASSERT_LE(std::fabs(approximated_dDv_dS - analytic_dDv_dS) /
- analytic_dDv_dS,
- 1e-10)
+ ASSERT_LE(std::fabs(expected_dDv_dS - analytic_dDv_dS), 1e-10)
<< "for expected derivative of water vapour diffusion with "
"respect to saturation "
- << approximated_dDv_dS
+ << expected_dDv_dS
<< " and for computed derivative of water vapour diffusion "
"with respect to saturation."
<< analytic_dDv_dS;