UZrHThermal

Computes thermal conductivity (W/m/K) and specific heat capacity (J/kg/K) for UZrH fuel based on the volume fraction of fuel constituents.

Description

Thermal properties for the uranium-zirconium-hydrogen fuel system , modeled in the material UZrHThermal, are from Evans et al. (2023).

The fuel thermal conductivity is calculated as the product of the diffusivity, density, and specific heat:

Where, is the thermal conductivity , is the diffusivity , is the density , and is the specific heat .

Because these properties vary based on the composition of the fuel (different H/Zr Ratios, , and %U) a simple mixture rule is used to calculate the thermal conductivity and specific heat over this parameter space. For the thermal conductivity, the volumetric fraction of the constituents is used in the mixture calculation as follows:

Where is the thermal conductivity of the constituents and is the volume fraction. For this model, the volume fraction of uranium is specified as an input and the volume fraction of is calculated as:

Seperately, the fuel heat capacity, which is applied to the fuel material, is calculated using a similar method:

Thermal Diffusivity

This model calculates both the thermal diffusivity for the and components individually to be used in the thermal conductivity calculation.

The thermal diffusivity for is based on the temperature and ratio of the constituents in the material. It is calculated as follows:

Where, is the thermal diffusivity of the , is the temperature (), and is the H-Zr Ratio ()

The thermal diffusivity for uranium, , is calculated as follows:

Where, is the thermal diffusivity of the and is the temperature (). Although the diffusivity is provided for the three phases of the metal, only the phase is used, as a phase change model is not yet implemented to account for the spatial distribution of the uranium phases.

Density

The density of the fuel material is calculated initally using the densities from the individual components. The theoretical density of the is assumed to be 19050 . The density for the is calculated as:

Density changes in the fuel itself due to dimensional changes are applied in the density model using the components from all deformation mechanisms included in the simulation.

Specific Heat Capacity

The specific heat capacity for the fuel is calculated using the invididual heat capacity components of the constituents. For the the heat capacity is calculated using the temperature, mass, and composition of the material:

Where is the specific heat capacity , is the hydrogen-to-zirconium ratio, is the temperature (K), and is the molar mass (kg) of the chemical.

The molar mass (kg/mol) is dependant on (the hydrogen-to-zirconium ratio), and is calculated using the following expression:

The specific heat capacity for uranium, , is calculated as follows:

Where is the specific heat capacity and is the temperature (K). Again, only the alpha phase is considered here; values for the various phases are provided with the intent of developing a phase change model.

Example Input Syntax

[Materials<<<{"href": "../../syntax/Materials/index.html"}>>>]
  [thermal_props]
    type = UZrHThermal<<<{"description": "Computes thermal conductivity (W/m/K) and specific heat capacity (J/kg/K) for UZrH fuel based on the volume fraction of fuel constituents.", "href": "UZrHThermal.html"}>>>
    specific_heat_scale_factor<<<{"description": "Optional scaling factor applied to the overall specific heat."}>>> = 1.0
    thermal_conductivity_scale_factor<<<{"description": "Optional scaling factor applied to the overall thermal conductivity."}>>> = 1.0
    U_volume_fraction<<<{"description": "Sets the volume fraction of uranium metal in the fuel"}>>> = 0.112
    HZr_ratio<<<{"description": "Sets the hydrogen-to-zirconium ratio of the fuel"}>>> = 1.6
    temperature<<<{"description": "Coupled temperature"}>>> = temp
    outputs<<<{"description": "Vector of output names where you would like to restrict the output of variables(s) associated with this object"}>>> = all
  []
[]
(test/tests/uzrh_thermal/1000.i)

Input Parameters

  • temperatureCoupled temperature

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled temperature

Required Parameters

  • HZr_ratio1.6Sets the hydrogen-to-zirconium ratio of the fuel

    Default:1.6

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Sets the hydrogen-to-zirconium ratio of the fuel

  • U_volume_fraction0.112Sets the volume fraction of uranium metal in the fuel

    Default:0.112

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Sets the volume fraction of uranium metal in the fuel

  • base_nameOptional parameter that allows the user to define multiple material systems on the same block, i.e. for multiple phases

    C++ Type:std::string

    Controllable:No

    Description:Optional parameter that allows the user to define multiple material systems on the same block, i.e. for multiple phases

  • blockThe list of blocks (ids or names) that this object will be applied

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

    Controllable:No

    Description:The list of blocks (ids or names) that this object will be applied

  • boundaryThe list of boundaries (ids or names) from the mesh where this object applies

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

    Controllable:No

    Description:The list of boundaries (ids or names) from the mesh where this object applies

  • computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the MaterialBase via MaterialBasePropertyInterface::getMaterialBase(). Non-computed MaterialBases are not sorted for dependencies.

  • constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

    Default:NONE

    C++ Type:MooseEnum

    Options:NONE, ELEMENT, SUBDOMAIN

    Controllable:No

    Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

  • declare_suffixAn optional suffix parameter that can be appended to any declared 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 declared properties. The suffix will be prepended with a '_' character.

Optional Parameters

  • 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.

  • implicitTrueDetermines whether this object is calculated using an implicit or explicit form

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Determines whether this object is calculated using an implicit or explicit form

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Controllable:No

    Description:The seed for the master random number generator

  • use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

  • output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)

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

    Controllable:No

    Description:List of material properties, from this material, to output (outputs must also be defined to an output type)

  • outputsnone Vector of output names where you would like to restrict the output of variables(s) associated with this object

    Default:none

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

    Controllable:No

    Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

Outputs 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

  • specific_heat_scale_factor1Optional scaling factor applied to the overall specific heat.

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Optional scaling factor applied to the overall specific heat.

  • thermal_conductivity_scale_factor1Optional scaling factor applied to the overall thermal conductivity.

    Default:1

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Optional scaling factor applied to the overall thermal conductivity.

Advanced: Scaling Factors Parameters

Input Files

References

  1. J. A. Evans, R. T. Sweet, and D. D. Keiser. MARVEL Reactor Fuel Performance Report. Technical Report INL/RPT-22-68555, Idaho National Laboratory, March 2023.[BibTeX]