MaterialPropertyLib::WaterVapourDensity Class Reference

Detailed Description

A model for water vapour density in the unsaturated porous media.

The water vapour density is given by

\[ \rho_v = h\, \rho_{vS}, \]

where \(h\) is the relative humidity according to

\[ h=\exp({\frac{p}{\rho_w R T}}), \]

with \(R\) the specific gas constant for water vapour, and \(\rho_{vS}\), is the saturated vapour density given by

\[ \rho_{vS}=10^{-3}\, \exp({19.819-4975.9/T}). \]

The specific gas constant for water vapour \(R=461.6\,\text{J}\,\text{kg}^{-1}\text{K}^{-1}\), the value is calculated by \(R_g/M_w\) with \(R_g= 8.3144621\,\text{J}\,\text{mol}^{-1}\text{K}^{-1}\), the ideal gas constant, and \(M_w=0.018016\,\text{kg}\,\text{mol}^{-1}\), the molar mass of water.

The formula of this density model is presented on page 20 of [21].

In the application, the vapour density related terms in the mass balance equation are multiplied with \(1-S\) with \( S \), the water saturation. Therefore the application of the water vapour density model is naturally restricted in the unsaturated zones.

Note

The temperature must be greater then the freezing temperature. In the paper the offset is 273K, not 273.15 which might cause small inconsistencies.

Definition at line 56 of file WaterVapourDensity.h.

#include <WaterVapourDensity.h>

Inheritance diagram for MaterialPropertyLib::WaterVapourDensity:

Collaboration diagram for MaterialPropertyLib::WaterVapourDensity:

Public Member Functions
	WaterVapourDensity (std::string name)
void	checkScale () const override
PropertyDataType	value (VariableArray const &variable_array, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const override
PropertyDataType	dValue (VariableArray const &variable_array, Variable const variable, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const override
Public Member Functions inherited from MaterialPropertyLib::Property
virtual	~Property ()
virtual PropertyDataType	initialValue (ParameterLib::SpatialPosition const &pos, double const t) const
virtual PropertyDataType	value () const
virtual PropertyDataType	value (VariableArray const &variable_array, VariableArray const &variable_array_prev, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
virtual PropertyDataType	dValue (VariableArray const &variable_array, VariableArray const &variable_array_prev, Variable const variable, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
virtual PropertyDataType	d2Value (VariableArray const &variable_array, Variable const variable1, Variable const variable2, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
	Default implementation: 2nd derivative of any constant property is zero.
virtual void	setProperties (std::vector< std::unique_ptr< Phase > > const &phases)
	Default implementation:
void	setScale (std::variant< Medium *, Phase *, Component * > scale)
template<typename T >
T	initialValue (ParameterLib::SpatialPosition const &pos, double const t) const
template<typename T >
T	value () const
template<typename T >
T	value (VariableArray const &variable_array, VariableArray const &variable_array_prev, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
template<typename T >
T	value (VariableArray const &variable_array, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
template<typename T >
T	dValue (VariableArray const &variable_array, VariableArray const &variable_array_prev, Variable const variable, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
template<typename T >
T	dValue (VariableArray const &variable_array, Variable const variable, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const
template<typename T >
T	d2Value (VariableArray const &variable_array, Variable const &variable1, Variable const &variable2, ParameterLib::SpatialPosition const &pos, double const t, double const dt) const

Additional Inherited Members
Protected Attributes inherited from MaterialPropertyLib::Property
std::string	name_
PropertyDataType	value_
	The single value of a property.
PropertyDataType	dvalue_
std::variant< Medium *, Phase *, Component * >	scale_

Constructor & Destructor Documentation

WaterVapourDensity()

MaterialPropertyLib::WaterVapourDensity::WaterVapourDensity ( std::string name )

inlineexplicit

Definition at line 59 of file WaterVapourDensity.h.

{ name_ = std::move(name); }

References MaterialPropertyLib::name, and MaterialPropertyLib::Property::name_.

Member Function Documentation

checkScale()

void MaterialPropertyLib::WaterVapourDensity::checkScale ( ) const

inlineoverridevirtual

Reimplemented from MaterialPropertyLib::Property.

Definition at line 60 of file WaterVapourDensity.h.

    {
        if (!std::holds_alternative<Phase*>(scale_))
        {
            OGS_FATAL(
                "The property 'WaterVapourDensity' is "
                "implemented on the 'Phase' scale only.");
        }
    }

References OGS_FATAL, and MaterialPropertyLib::Property::scale_.

dValue()

PropertyDataType MaterialPropertyLib::WaterVapourDensity::dValue ( VariableArray const & variable_array, Variable const variable, ParameterLib::SpatialPosition const & pos, double const t, double const dt ) const

overridevirtual

Returns

The derivative of water vapour density with respect to temperature or phase (water) pressure.

Reimplemented from MaterialPropertyLib::Property.

Definition at line 56 of file WaterVapourDensity.cpp.

{
    double const p = variable_array.liquid_phase_pressure;
    double const T = variable_array.temperature;
    assert(T >= 273.);
    double const water_density = variable_array.density;
    assert(water_density > 0.);
 
    if (variable == Variable::temperature)
    {
        double const h = humidity(T, p, water_density);
        double const rho_v = h * saturatedVaporDensity(T);
        double const drho_vS_dT = dsaturatedVaporDensitydT(T);
 
        return h * drho_vS_dT - rho_v * p /
                                    (water_density * T * T *
                                     MaterialLib::PhysicalConstant::
                                         SpecificGasConstant::WaterVapour);
    }
 
    if (variable == Variable::liquid_phase_pressure)
    {
        double const factor =
            1.0 /
            (MaterialLib::PhysicalConstant::SpecificGasConstant::WaterVapour *
             T * water_density);
        double const dhumiditydp = factor * std::exp(factor * p);
 
        return dhumiditydp * saturatedVaporDensity(T);
    }
 
    OGS_FATAL(
        "WaterVapourDensity::dValue is implemented for derivatives with "
        "respect to temperature or liquid_phase_pressure only.");
}

References MaterialPropertyLib::VariableArray::density, MaterialPropertyLib::dsaturatedVaporDensitydT(), MaterialPropertyLib::humidity(), MaterialPropertyLib::liquid_phase_pressure, MaterialPropertyLib::VariableArray::liquid_phase_pressure, OGS_FATAL, MaterialPropertyLib::saturatedVaporDensity(), MaterialPropertyLib::temperature, MaterialPropertyLib::VariableArray::temperature, and MaterialLib::PhysicalConstant::SpecificGasConstant::WaterVapour.

value()

PropertyDataType MaterialPropertyLib::WaterVapourDensity::value ( VariableArray const & variable_array, ParameterLib::SpatialPosition const & pos, double const t, double const dt ) const

overridevirtual

Returns

The water vapour density.

Reimplemented from MaterialPropertyLib::Property.

Definition at line 42 of file WaterVapourDensity.cpp.

{
    double const p = variable_array.liquid_phase_pressure;
    double const T = variable_array.temperature;
    assert(T >= 273.);
    double const water_density = variable_array.density;
    assert(water_density > 0.);
 
    return humidity(T, p, water_density) * saturatedVaporDensity(T);
}

References MaterialPropertyLib::VariableArray::density, MaterialPropertyLib::humidity(), MaterialPropertyLib::VariableArray::liquid_phase_pressure, MaterialPropertyLib::saturatedVaporDensity(), and MaterialPropertyLib::VariableArray::temperature.

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The documentation for this class was generated from the following files:

• MaterialLib/MPL/Properties/Density/WaterVapourDensity.h
• MaterialLib/MPL/Properties/Density/WaterVapourDensity.cpp