B4CThermal

Compute B4C thermal conductivity and specific heat as functions of temperature, capture burnup, and porosity.

Description

This computes the thermal conductivity and specific heat of B4C. Due to the Grüneisen anharmonicity parameter () being dependent on specific heat, thermal conductivity is calculated after specific heat. The thermal conductivity also requires porosity and a capture burnup. Capture burnup, , is the fraction of boron atoms that have captured a neutron making them unavailable to capture further neutrons compared to the initial total available boron atoms.

Add the prefix AD (e.g., ADB4CThermal) to use the AD version. Also, it is recommended to set Outputs parameter (e.g., Outputs = all) to visualize thermal properties as the models are dependent on many different inputs, and the behavior is unknown for every combination of inputs.

Thermal Conductivity

The implemented thermal conductivity model is model 3 from Qu et al. (2022). The implementation differs in that related material models available during multiphysics simulations use calculated values instead of assumed constants used in Qu et al. (2022).

The thermal conductivity (W/m-K), , is

where is 3.6 assuming B4C is irradiated. terms are related to initial porosity, , and current porosity, . The current porosity is provided by either an assumption (Qu et al., 2022) or by another material model during simulation. Either will need to be provided to this model. is from model 2 defined as

where is a fit to experimental data (Qu et al., 2022) as

where is temperature in Kelvin. is from model 1 defined as

with

where as the number of atoms in a unit cell of B4C, is the Boltzmann's constant, is the shear modulus assumed as a constant 200 GPa, is the average atomic volume of m, and the imperfection scattering parameter is

where is the atomic weight of the enriched boron and is the atomic weight of a unit cell of B4C. is

where is the atomic weight of lithium produced from neutron capture, corresponds to a fractional burnup of total boron, , and are atomic radius for lithium and boron as m and m, respectively, , and is

where is Poisson's ratio of 0.18. is approximated as

where is the mean linear coefficient of thermal expansion, is the bulk modulus set as a constant 245 GPa, is the theoretical density of B4C taken as 2389 kg/m, and is the specific heat.

Specific Heat

The specific heat (J/kg-K) is provided by a fit to experimental data (Thévenot, 1990) as

where is the atomic weight of B4C.

Example Input Syntax

[Materials<<<{"href": "../../syntax/Materials/index.html"}>>>]
  [new_mat]
    type = B4CThermal<<<{"description": "Compute B4C thermal conductivity and specific heat as functions of temperature, capture burnup, and porosity.", "href": "B4CThermal.html"}>>>
    temperature<<<{"description": "Coupled temperature"}>>> = temperature
    outputs<<<{"description": "Vector of output names where you would like to restrict the output of variables(s) associated with this object"}>>> = all
  []
[]
(test/tests/thermalB4C/exact.i)

Input Parameters

  • temperatureCoupled temperature

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

    Unit:(no unit assumed)

    Controllable:No

    Description:Coupled temperature

Required Parameters

  • 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

  • boron_10_enrichment0.92Boron 10 atomic fraction.

    Default:0.92

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Boron 10 atomic fraction.

  • 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

  • capture_burnupcapture_burnupMaterial property name for burnup of boron captures.

    Default:capture_burnup

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:Material property name for burnup of boron captures.

  • 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.

  • initial_density2269.55Initial density of B4C in kg/m^3.

    Default:2269.55

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Initial density of B4C in kg/m^3.

  • mean_thermal_expansion_coefficient_name4.323e-06Material property name for mean linear thermal expansion coefficient.

    Default:4.323e-06

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:Material property name for mean linear thermal expansion coefficient.

  • poissons_ratio0.18Poisson's ratio of B4C.

    Default:0.18

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Poisson's ratio of B4C.

  • porosityporosityPorosity material property name.

    Default:porosity

    C++ Type:MaterialPropertyName

    Unit:(no unit assumed)

    Controllable:No

    Description:Porosity material property name.

  • theoretical_density2389Theorectical maximum density of B4C in kg/m^3.

    Default:2389

    C++ Type:double

    Unit:(no unit assumed)

    Controllable:No

    Description:Theorectical maximum density of B4C in kg/m^3.

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. Zhixue Qu, Chuanjin Yu, Yitong Wei, Xiping Su, and Aibing Du. Thermal conductivity of boron carbide under fast neutron irradiation. Journal of Advanced Ceramics, 11:482–494, 3 2022. doi:10.1007/s40145-022-0572-8.[BibTeX]
  2. Francois Thévenot. Boron carbide—a comprehensive review. Journal of the European Ceramic Society, 6(4):205–225, 1990. doi:10.1016/0955-2219(90)90048-K.[BibTeX]