FVBoundedValueConstraint

This object implements the residuals that enforce the constraint

var element = document.getElementById("moose-equation-4c23dabb-8961-470b-8e22-3b2782350309");katex.render("\\phi > \\phi_0 \\in \\Omega", element, {displayMode:true,throwOnError:false});

var element = document.getElementById("moose-equation-09b8feb8-82c1-493b-855a-63c06c7ec0d4");katex.render("\\phi < \\phi_0 \\in \\Omega", element, {displayMode:true,throwOnError:false});

using a Lagrange multiplier approach. E.g. this object enforces the constraint that the value of $var element = document.getElementById("moose-equation-2649b7f1-21bb-46fa-8331-a9174d09321e");katex.render("\\phi", element, {displayMode:false,throwOnError:false});$ in the domain has to be above or below a certain value.

warning

The contribution to the diagonal of the system of this kernel is null, which introduces a saddle point. Make sure to use a NONZERO shift in your preconditioner.

Example input syntax

In this example, the value of the variable v is forced to be positive using a FVBoundedValueConstraint. This accelerates the convergence to the solution, as the initial condition is negative and the solution is everywhere positive.

[Variables]
  [v]
    type = MooseVariableFVReal
  []
  [lambda]
    type = MooseVariableScalar
  []
[]

[FVKernels]
  [diff]
    type = FVDiffusion
    variable = v
    coeff = coeff
  []
  [average]
    type = FVPointValueConstraint
    variable = v
    phi0 = 13
    lambda = lambda
    point = '0.3 0 0'
  []
[]

Input Parameters

bound_typeWhether a minimum or a maximum bound
C++ Type:MooseEnum
Unit:(no unit assumed)
Options:lower_than, higher_than
Controllable:No
Description:Whether a minimum or a maximum bound
lambdaLagrange multiplier variable
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Lagrange multiplier variable
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

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Unit:(no unit assumed)
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
phi00The min or max bound
Default:0
C++ Type:PostprocessorName
Unit:(no unit assumed)
Controllable:No
Description:The min or max bound
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.

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.
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
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

ghost_layers1The number of layers of elements to ghost.
Default:1
C++ Type:unsigned short
Unit:(no unit assumed)
Controllable:No
Description:The number of layers of elements to ghost.
use_point_neighborsFalseWhether to use point neighbors, which introduces additional ghosting to that used for simple face neighbors.
Default:False
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Whether to use point neighbors, which introduces additional ghosting to that used for simple face neighbors.

Parallel Ghosting Parameters

(moose/test/tests/fvkernels/constraints/point_value.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 4
[]

[Variables]
  [v]
    type = MooseVariableFVReal
  []
  [lambda]
    type = MooseVariableScalar
  []
[]

[FVKernels]
  [diff]
    type = FVDiffusion
    variable = v
    coeff = coeff
  []
  [average]
    type = FVPointValueConstraint
    variable = v
    phi0 = 13
    lambda = lambda
    point = '0.3 0 0'
  []
[]

[FVBCs]
  [left]
    type = FVDirichletBC
    variable = v
    boundary = left
    value = 7
  []
[]

[Materials]
  [diff]
    type = ADGenericFunctorMaterial
    prop_names = 'coeff'
    prop_values = '1'
  []
[]

[Executioner]
  type = Steady
  solve_type = 'PJFNK'
  petsc_options_iname = '-pc_type -pc_factor_shift_type'
  petsc_options_value = 'lu NONZERO'
[]

[Outputs]
  exodus = true
[]

Example input syntax
Input Parameters