NeumannBC

Imposes the integrated boundary condition , where is a constant, controllable value.

Description

NeumannBC is the simplest type of IntegratedBC, and is used for imposing flux boundary conditions on systems of partial differential equations (PDEs). This class is appropriate to use for PDEs of the form (1) where is the domain, and is its boundary. In this case, a NeumannBC object is used to impose the condition (3) on the subset of the boundary denoted by . The value parameter corresponds to the constant , and the user must define one or more sidesets corresponding to the boundary subset . The normal derivative notation is , where is the outward unit normal to .

Example Input Syntax

  [./right]
    type = NeumannBC
    variable = u
    boundary = right
    value = 2
  [../]
(test/tests/bcs/1d_neumann/1d_neumann.i)

Input Parameters

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

    C++ Type:NonlinearVariableName

    Options:

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

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

    C++ Type:std::vector

    Options:

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

Required Parameters

  • value0The value of the gradient on the boundary.

    Default:0

    C++ Type:double

    Options:

    Description:The value of the gradient on the boundary.

Optional Parameters

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Options:

    Description:Set the enabled status of the MooseObject.

  • 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

    Options:

    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.)

  • 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

    Options:

    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.

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

    C++ Type:std::vector

    Options:

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

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Options:

    Description:The seed for the master random number generator

  • 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

    Options:

    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.)

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

    Default:True

    C++ Type:bool

    Options:

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

Advanced Parameters

  • vector_tagsnontimeThe tag for the vectors this Kernel should fill

    Default:nontime

    C++ Type:MultiMooseEnum

    Options:nontime time

    Description:The tag for the vectors this Kernel should fill

  • extra_vector_tagsThe extra tags for the vectors this Kernel should fill

    C++ Type:std::vector

    Options:

    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

    Description:The tag for the matrices this Kernel should fill

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

    C++ Type:std::vector

    Options:

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

Tagging Parameters

Input Files

Child Objects