IdealRealGasMixtureFluidProperties

This is a VaporMixtureFluidProperties that assumes an ideal vapor mixture but allows real vapor components, rather than assume that each component is an ideal gas. This model (which corresponds to "Model A" in (Hansel et al., 2018)) assumes that each gas in the mixture occupies the entire mixture volume at a common temperature and each has a partial pressure and is considered an ideal gas mixture approximation applied to real gases.

Formulation

Consider a mixture of gases. Let the subscript denote the component index and the lack of a subscript denote a mixture quantity. The mass fraction is defined as the ratio of the component mass to the mixture mass :

(1)

where the densities and are with respect to the mixture volume. The molar fraction is defined as the ratio of the component number of moles to the mixture number of moles :

The mixture molar mass can be computed using the component molar fractions and molar masses :

The mass fraction and molar fraction are related as

Note the following relation for all mass-specific quantities, such as specific volume and specific internal energy:

where is the component equation of state call for , evaluated at the partial pressure and common temperature.

Note that the mixture density should be computed as

instead of a summation of component densities, since this would be inconsistent if any component is not an ideal gas.

Transport properties, such as dynamic viscosity and thermal conductivity are computed as

(2)(3)

The gases share a temperature , and each has a partial pressure , which is an assumption known as Dalton's law:

where by Eq. (1),

Note

Sound Speed and Specific Heat Capacities

The mixture sound speed and heat capacities are computed directly from thermodynamic definitions relative to mixture properties, rather than constituent properties:

(4)(5)(6)

Since the independent parameters are and , the following relations can be used:

Implementation

The available interfaces are summarized in the following table, where the rows correspond to the computed quantity, and the columns correspond to the various combinations of input arguments. Note that the notation denotes the nonlinear solve of the equation for :

Quantity
Eq. (6)Eq. (6)Eq. (6)
Eq. (4)Eq. (4)
Eq. (5)Eq. (5)
Eq. (2)
Eq. (3)

Input Parameters

  • fp_primaryName of fluid properties user object for primary vapor component

    C++ Type:UserObjectName

    Controllable:No

    Description:Name of fluid properties user object for primary vapor component

  • fp_secondaryName of fluid properties user object(s) for secondary vapor component(s)

    C++ Type:std::vector<UserObjectName>

    Controllable:No

    Description:Name of fluid properties user object(s) for secondary vapor component(s)

Required Parameters

  • _T_mix_max1300Maximum temperature of the mixture

    Default:1300

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Maximum temperature of the mixture

  • emit_on_nannoneWhether to raise a warning, an exception (usually triggering a retry with a smaller time step) or an error (ending the simulation)

    Default:none

    C++ Type:MooseEnum

    Options:none, warning, exception, error

    Controllable:No

    Description:Whether to raise a warning, an exception (usually triggering a retry with a smaller time step) or an error (ending the simulation)

Optional Parameters

  • allow_imperfect_jacobiansFalsetrue to allow unimplemented property derivative terms to be set to zero for the AD API

    Default:False

    C++ Type:bool

    Controllable:No

    Description:true to allow unimplemented property derivative terms to be set to zero for the AD API

  • control_tagsAdds user-defined labels for accessing object parameters via control logic.

    C++ Type:std::vector<std::string>

    Controllable:No

    Description:Adds user-defined labels for accessing object parameters via control logic.

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Controllable:Yes

    Description:Set the enabled status of the MooseObject.

  • fp_typeunspecified-typeType of the fluid property object

    Default:unspecified-type

    C++ Type:FPType

    Controllable:No

    Description:Type of the fluid property object

Advanced Parameters

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

References

  1. Joshua E. Hansel, Matthias S. Kunick, Ray A. Berry, and David Andrs. Non-condensable gases in RELAP-7. Technical Report INL/EXT-18-51163, Idaho National Laboratory, 2018.[BibTeX]