GrayLambertNeumannBC

This BC imposes a heat flux density that is computed from the GrayLambertSurfaceRadiationBase userobject.

This boundary condition computes the heat flux density resulting from the radiative heat transfer between surfaces adjacent to this boundary. These surfaces must be diffuse, gray radiators (Lambert radiators). The heat flux is computed by the net radiation method described in Modest (2013). More information is available here.

There are two modes available for operating this boundary condition. The mode can be switched by the reconstruct_emission parameter. If set to false, the object queries the net radiation object (GrayLambertSurfaceRadiationBase or derived class) object for the net heat flux density on the surface. This heat flux density is applied as a constant for each participating sideset. If the sidesets are large and the flat heat flux densities on two adjacent sidesets sufficiently different, then the temperature will be non-smooth.

A smoother temperature distribution on the surface is usually obtained by noting that a large fraction of the spatial distribution of the heat flux stems from the temperature distribution and hence from the emission. The approximation made is that the emission is allowed to spatially vary, while the irradiation from other sidesets to the given sideset is assumed to be spatially flat. The heat flux at location on sideset is computed by:

where is the Stefan-Boltzmann constant, the emissivity of sideset , and the average irradiation into sideset .

[Problem<<<{"href": "../../syntax/Problem/index.html"}>>>]
  kernel_coverage_check = false
[]

[Mesh<<<{"href": "../../syntax/Mesh/index.html"}>>>]
  type = MeshGeneratorMesh

  [./cartesian]
    type = CartesianMeshGenerator<<<{"description": "This CartesianMeshGenerator creates a non-uniform Cartesian mesh.", "href": "../meshgenerators/CartesianMeshGenerator.html"}>>>
    dim<<<{"description": "The dimension of the mesh to be generated"}>>> = 2
    dx<<<{"description": "Intervals in the X direction"}>>> = '1 1 1'
    ix<<<{"description": "Number of grids in all intervals in the X direction (default to all one)"}>>> = '2 2 2'
    dy<<<{"description": "Intervals in the Y direction (required when dim>1 otherwise ignored)"}>>> = '5'
    iy<<<{"description": "Number of grids in all intervals in the Y direction (default to all one)"}>>> = '10'
    subdomain_id<<<{"description": "Block IDs (default to all zero)"}>>> = '1 2 3'
  [../]

  [./break_sides]
    type = BreakBoundaryOnSubdomainGenerator<<<{"description": "Break boundaries based on the subdomains to which their sides are attached. Naming convention for the new boundaries will be the old boundary name plus \"_to_\" plus the subdomain name", "href": "../meshgenerators/BreakBoundaryOnSubdomainGenerator.html"}>>>
    boundaries<<<{"description": "Boundaries to be broken. Default means to break all boundaries"}>>> = 'bottom top'
    input<<<{"description": "The mesh we want to modify"}>>> = cartesian
  [../]

  [./left_interior]
    type = SideSetsBetweenSubdomainsGenerator<<<{"description": "MeshGenerator that creates a sideset composed of the nodes located between two or more subdomains.", "href": "../meshgenerators/SideSetsBetweenSubdomainsGenerator.html"}>>>
    primary_block<<<{"description": "The primary set of blocks for which to draw a sideset between"}>>> = 1
    paired_block<<<{"description": "The paired set of blocks for which to draw a sideset between"}>>> = 2
    new_boundary<<<{"description": "The list of boundary names to create on the supplied subdomain"}>>> = left_interior
    input<<<{"description": "The mesh we want to modify"}>>> = break_sides
  [../]

  [./right_interior]
    type = SideSetsBetweenSubdomainsGenerator<<<{"description": "MeshGenerator that creates a sideset composed of the nodes located between two or more subdomains.", "href": "../meshgenerators/SideSetsBetweenSubdomainsGenerator.html"}>>>
    primary_block<<<{"description": "The primary set of blocks for which to draw a sideset between"}>>> = 3
    paired_block<<<{"description": "The paired set of blocks for which to draw a sideset between"}>>> = 2
    new_boundary<<<{"description": "The list of boundary names to create on the supplied subdomain"}>>> = right_interior
    input<<<{"description": "The mesh we want to modify"}>>> = left_interior
  [../]
  [./rename]
    type = RenameBlockGenerator<<<{"description": "Changes the block IDs and/or block names for a given set of blocks defined by either block ID or block name. The changes are independent of ordering. The merging of blocks is supported.", "href": "../meshgenerators/RenameBlockGenerator.html"}>>>
    input<<<{"description": "The mesh we want to modify"}>>> = right_interior
    old_block<<<{"description": "Elements with these block ID(s)/name(s) will be given the new block information specified in 'new_block'"}>>> = '1 2 3'
    new_block<<<{"description": "The new block ID(s)/name(s) to be given by the elements defined in 'old_block'."}>>> = '1 4 3'
  [../]
[]

[Variables<<<{"href": "../../syntax/Variables/index.html"}>>>]
  [./temperature]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 300
    block = '1 3'
  [../]
[]

[Kernels<<<{"href": "../../syntax/Kernels/index.html"}>>>]
  [./heat_conduction]
    type = HeatConduction<<<{"description": "Diffusive heat conduction term $-\\nabla\\cdot(k\\nabla T)$ of the thermal energy conservation equation", "href": "../kernels/HeatConduction.html"}>>>
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = temperature
    diffusion_coefficient<<<{"description": "Property name of the diffusion coefficient"}>>> = 1
    block<<<{"description": "The list of blocks (ids or names) that this object will be applied"}>>> = '1 3'
  [../]
[]

[UserObjects<<<{"href": "../../syntax/UserObjects/index.html"}>>>]
  [./cavity_radiation]
    type = ConstantViewFactorSurfaceRadiation<<<{"description": "ConstantViewFactorSurfaceRadiation computes radiative heat transfer between side sets and the view factors are provided in the input file", "href": "../userobjects/ConstantViewFactorSurfaceRadiation.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'left_interior right_interior bottom_to_2 top_to_2'
    temperature<<<{"description": "The coupled temperature variable."}>>> = temperature
    emissivity<<<{"description": "Emissivities for each boundary."}>>> = '0.8 0.8 0.8 0.8'
    adiabatic_boundary<<<{"description": "The list of boundary IDs from the mesh that are adiabatic."}>>> = 'bottom_to_2 top_to_2'
    # these view factors are made up to exactly balance energy
    # transfer through the cavity
    view_factors<<<{"description": "The view factors from sideset i to sideset j."}>>> = '0    0.8 0.1 0.1;
                    0.8  0   0.1 0.1;
                    0.45 0.45  0 0.1;
                    0.45 0.45 0.1  0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'INITIAL LINEAR TIMESTEP_END'
  [../]
[]

[BCs<<<{"href": "../../syntax/BCs/index.html"}>>>]
  [./bottom_left]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "DirichletBC.html"}>>>
    preset<<<{"description": "Whether or not to preset the BC (apply the value before the solve begins)."}>>> = false
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = temperature
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = bottom_to_1
    value<<<{"description": "Value of the BC"}>>> = 1500
  [../]

  [./top_right]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "DirichletBC.html"}>>>
    preset<<<{"description": "Whether or not to preset the BC (apply the value before the solve begins)."}>>> = false
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = temperature
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = top_to_3
    value<<<{"description": "Value of the BC"}>>> = 300
  [../]

  [./radiation]
    type = GrayLambertNeumannBC<<<{"description": "This BC imposes a heat flux density that is computed from the GrayLambertSurfaceRadiationBase userobject.", "href": "GrayLambertNeumannBC.html"}>>>
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = temperature
    reconstruct_emission<<<{"description": "Flag to apply constant heat flux on sideset or reconstruct emission by T^4 law."}>>> = false
    surface_radiation_object_name<<<{"description": "Name of the GrayLambertSurfaceRadiationBase UO"}>>> = cavity_radiation
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = 'left_interior right_interior'
  [../]
[]

[Postprocessors<<<{"href": "../../syntax/Postprocessors/index.html"}>>>]
  [./qdot_left]
    type = GrayLambertSurfaceRadiationPP<<<{"description": "This postprocessor allows to extract radiosity, heat flux density, and temperature from the GrayLambertSurfaceRadiationBase object.", "href": "../postprocessors/GrayLambertSurfaceRadiationPP.html"}>>>
    boundary<<<{"description": "The boundary of interest."}>>> = left_interior
    surface_radiation_object_name<<<{"description": "Name of the GrayLambertSurfaceRadiationBase UO"}>>> = cavity_radiation
    return_type<<<{"description": "Requested return type: RADIOSITY | HEAT_FLUX_DENSITY | TEMPERATURE"}>>> = HEAT_FLUX_DENSITY
  [../]

  [./qdot_right]
    type = GrayLambertSurfaceRadiationPP<<<{"description": "This postprocessor allows to extract radiosity, heat flux density, and temperature from the GrayLambertSurfaceRadiationBase object.", "href": "../postprocessors/GrayLambertSurfaceRadiationPP.html"}>>>
    boundary<<<{"description": "The boundary of interest."}>>> = right_interior
    surface_radiation_object_name<<<{"description": "Name of the GrayLambertSurfaceRadiationBase UO"}>>> = cavity_radiation
    return_type<<<{"description": "Requested return type: RADIOSITY | HEAT_FLUX_DENSITY | TEMPERATURE"}>>> = HEAT_FLUX_DENSITY
  [../]

  [./qdot_top]
    type = GrayLambertSurfaceRadiationPP<<<{"description": "This postprocessor allows to extract radiosity, heat flux density, and temperature from the GrayLambertSurfaceRadiationBase object.", "href": "../postprocessors/GrayLambertSurfaceRadiationPP.html"}>>>
    boundary<<<{"description": "The boundary of interest."}>>> = top_to_2
    surface_radiation_object_name<<<{"description": "Name of the GrayLambertSurfaceRadiationBase UO"}>>> = cavity_radiation
    return_type<<<{"description": "Requested return type: RADIOSITY | HEAT_FLUX_DENSITY | TEMPERATURE"}>>> = HEAT_FLUX_DENSITY
  [../]

  [./qdot_bottom]
    type = GrayLambertSurfaceRadiationPP<<<{"description": "This postprocessor allows to extract radiosity, heat flux density, and temperature from the GrayLambertSurfaceRadiationBase object.", "href": "../postprocessors/GrayLambertSurfaceRadiationPP.html"}>>>
    boundary<<<{"description": "The boundary of interest."}>>> = bottom_to_2
    surface_radiation_object_name<<<{"description": "Name of the GrayLambertSurfaceRadiationBase UO"}>>> = cavity_radiation
    return_type<<<{"description": "Requested return type: RADIOSITY | HEAT_FLUX_DENSITY | TEMPERATURE"}>>> = HEAT_FLUX_DENSITY
  [../]
[]

[Executioner<<<{"href": "../../syntax/Executioner/index.html"}>>>]
  type = Steady
[]

[Outputs<<<{"href": "../../syntax/Outputs/index.html"}>>>]
  exodus<<<{"description": "Output the results using the default settings for Exodus output."}>>> = true
[]
(moose/modules/heat_transfer/test/tests/gray_lambert_radiator/coupled_heat_conduction.i)

Input Parameters

  • boundaryThe list of boundary IDs from the mesh where this object applies

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

    Controllable:No

    Description:The list of boundary IDs from the mesh where this object applies

  • surface_radiation_object_nameName of the GrayLambertSurfaceRadiationBase UO

    C++ Type:UserObjectName

    Controllable:No

    Description:Name of the GrayLambertSurfaceRadiationBase UO

  • variableThe name of the variable that this residual object operates on

    C++ Type:NonlinearVariableName

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of the variable that this residual object operates on

Required Parameters

  • displacementsThe displacements

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The displacements

  • reconstruct_emissionTrueFlag to apply constant heat flux on sideset or reconstruct emission by T^4 law.

    Default:True

    C++ Type:bool

    Controllable:No

    Description:Flag to apply constant heat flux on sideset or reconstruct emission by T^4 law.

Optional Parameters

  • absolute_value_vector_tagsThe tags for the vectors this residual object should fill with the absolute value of the residual contribution

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

    Controllable:No

    Description:The tags for the vectors this residual object should fill with the absolute value of the residual contribution

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

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

    Controllable:No

    Description:The extra tags for the matrices this Kernel should fill

  • extra_vector_tagsThe extra tags for the vectors this Kernel should fill

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

    Controllable:No

    Description:The extra tags for the vectors this Kernel should fill

  • matrix_tagssystemThe tag for the matrices this Kernel should fill

    Default:system

    C++ Type:MultiMooseEnum

    Options:nontime, system

    Controllable:No

    Description:The tag for the matrices this Kernel should fill

  • vector_tagsnontimeThe tag for the vectors this Kernel should fill

    Default:nontime

    C++ Type:MultiMooseEnum

    Options:nontime, time

    Controllable:No

    Description:The tag for the vectors this Kernel should fill

Contribution To Tagged Field Data 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.

  • diag_save_inThe name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

  • 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

  • save_inThe name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

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

    Unit:(no unit assumed)

    Controllable:No

    Description:The name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

  • 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

  • skip_execution_outside_variable_domainFalseWhether to skip execution of this boundary condition when the variable it applies to is not defined on the boundary. This can facilitate setups with moving variable domains and fixed boundaries. Note that the FEProblem boundary-restricted integrity checks will also need to be turned off if using this option

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether to skip execution of this boundary condition when the variable it applies to is not defined on the boundary. This can facilitate setups with moving variable domains and fixed boundaries. Note that the FEProblem boundary-restricted integrity checks will also need to be turned off if using this option

  • 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

  • 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. M.F. Modest. Radiative Heat Transfer. Elsevier Science, 2013. ISBN 9780123869906. URL: https://books.google.com/books?id=J2KZq0e4lCIC.[BibTeX]