FVNeumannBC

Neumann boundary condition for finite volume method.

Overview

A FVNeumannBC may be used to specify a diffusive or an advective flux. For example, to specify a flux boundary condition in the following diffusion problem, a FVNeumannBC with a constant value of may be used.

where is the domain, is its boundary, and is a point on the domain or its boundary. In this case, a FVNeumannBC object is used to impose the condition (2) on the subset of the boundary denoted by . In this case, the value field corresponds to the constant , and the user must define one or more sidesets corresponding to the boundary to pass to the boundary argument. For this particular problem, an additional boundary condition, for example a FVDirichletBC as in (3) would also be necessary to remove the nullspace.

Likewise, to specify an advective flux of constant value in a 1D advection problem with an advective velocity :

The advective flux, the value to specify to the boundary condition (2), is .

Modeling a multi-dimensional problem will require a FVNeumannBC per component.

commentnote

When using the Navier Stokes module, FVNeumannBC may not be available for use with velocity and pressure, as additional information is required on either the gradient or direction of these variables to model fully developed flow for example. Specific boundary conditions are provided, see for example INSFVOutletPressureBC.

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

  • variableThe name of the variable that this boundary condition applies to

    C++ Type:NonlinearVariableName

    Controllable:No

    Description:The name of the variable that this boundary condition applies to

Required Parameters

  • displacementsThe displacements

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

    Controllable:No

    Description:The displacements

  • 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

    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.

  • value0The value of the flux crossing the boundary.

    Default:0

    C++ Type:double

    Controllable:No

    Description:The value of the flux crossing the boundary.

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

Tagging 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

  • 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

Input Files