MatNeumannBC

Imposes the integrated boundary condition $var element = document.getElementById("moose-equation-17551157-e7c7-4afd-97c2-5ee99a0a5c46");katex.render("\\frac{C \\partial u}{\\partial n}=M*h", element, {displayMode:false,throwOnError:false});$ , where $var element = document.getElementById("moose-equation-9b01d3e1-7431-4794-a294-c1f6b046cec1");katex.render("h", element, {displayMode:false,throwOnError:false});$ is a constant, $var element = document.getElementById("moose-equation-fe11dc45-a879-4923-bc6e-7108fa1a2de1");katex.render("M", element, {displayMode:false,throwOnError:false});$ is a material property, and $var element = document.getElementById("moose-equation-97a5b45f-a63f-401f-9cf7-03d752042296");katex.render("C", element, {displayMode:false,throwOnError:false});$ is a coefficient defined by the kernel for $var element = document.getElementById("moose-equation-c02cb291-41da-4a24-bcbd-9a1cb57f543d");katex.render("u", element, {displayMode:false,throwOnError:false});$ .

Description

MatNeumannBC is a generalization of NeumannBC which is used for imposing flux boundary conditions on systems of partial differential equations (PDEs) where the flux is represented by the product of a constant and a MOOSE Material Material. That is, for a PDE of the form $var element = document.getElementById("moose-equation-1d4b487a-0ae7-4269-ac2e-4315e46598ed");katex.render("\\begin{aligned} -\\nabla \\cdot C (\\nabla u) &= f && \\quad \\in \\Omega \\\\ u &= g(t,\\vec{x}) && \\quad \\in \\partial \\Omega_D \\\\ C \\frac{\\partial u}{\\partial n} &= hM(t,\\vec{x}) && \\quad \\in \\partial \\Omega_N, \\end{aligned}", element, {displayMode:true,throwOnError:false});$ where $var element = document.getElementById("moose-equation-b314cca5-4e03-4791-9a0c-24061a19b105");katex.render("\\Omega \\subset \\mathbb{R}^n", element, {displayMode:false,throwOnError:false});$ is the domain, and $var element = document.getElementById("moose-equation-8b19ae5c-27cc-4569-b312-74989e447816");katex.render("\\partial \\Omega = \\partial \\Omega_D \\cup \\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ is its boundary, a MatNeumannBC object can be used to impose condition (3) if the material is well-defined for all relevant times and $var element = document.getElementById("moose-equation-172dfc14-fd9c-4dc7-b56c-7deede6feb8e");katex.render("\\vec{x} \\in \\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ . In this case, the boundary_material parameter corresponds to a MOOSE Material object, and the user must define one or more sidesets corresponding to the boundary subset $var element = document.getElementById("moose-equation-b4b2713e-9dcc-4cc5-a3c3-f2c663409033");katex.render("\\partial \\Omega_N", element, {displayMode:false,throwOnError:false});$ via the boundary parameter.

Example Input Syntax

[./top]
  type = MatNeumannBC
  variable = u
  boundary = top
  value = 2
  boundary_material = hm
[../]

Input Parameters

boundaryThe list of boundary IDs from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Unit:(no unit assumed)
Controllable:No
Description:The list of boundary IDs from the mesh where this object applies
boundary_materialMaterial property multiplying the constant that will be enforced by the BC
C++ Type:MaterialPropertyName
Unit:(no unit assumed)
Controllable:No
Description:Material property multiplying the constant that will be enforced by the BC
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
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
Unit:(no unit assumed)
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.
value0For a Laplacian problem, the value of the gradient dotted with the normals on the boundary.
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:Yes
Description:For a Laplacian problem, the value of the gradient dotted with the normals on 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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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

(moose/test/tests/bcs/mat_neumann_bc/mat_neumann.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmax = 10
  ymax = 10
  nx = 10
  ny = 10
[]

[Variables]
  [./u]
  [../]
[]

[AuxVariables]
  [./phi]
  [../]
[]

[ICs]
  [./phi_IC]
    type = FunctionIC
    variable = phi
    function = ic_func_phi
  [../]
[]

[Functions]
  [./ic_func_phi]
    type = ParsedFunction
    expression = '0.5 * (1 - tanh((x - 5) / 0.8))'
  [../]
[]

[BCs]
  [./top]
    type = MatNeumannBC
    variable = u
    boundary = top
    value = 2
    boundary_material = hm
  [../]
[]

[Kernels]
  [./dudt]
    type = TimeDerivative
    variable = u
  [../]
  [./diff]
    type = Diffusion
    variable = u
  [../]
[]

[Materials]
  [./hm]
    type = ParsedMaterial
    property_name = hm
    coupled_variables = 'phi'
    expression = '3*phi^2 - 2*phi^3'
    outputs = exodus
  [../]
[]

[Executioner]
  type = Transient

  solve_type = 'PJFNK'
  end_time = 10
[]

[Outputs]
  exodus = true
[]

Description
Example Input Syntax
Input Parameters