LineSegmentLevelSetAux

Auxiliary Kernel that calcuates level set value using line segments' description.

Description

The LineSegmentLevelSetAux calculates level set values for an interface that is defined by a set of line segments(LineSegmentCutSetUserObject). Usually the value of level set at a given point is calculated as a signed distance of this point from the boundary of the interface, with the sign determined by whether x is inside the closed interface contour.

Example Input File Syntax

[./ls]
  type = LineSegmentLevelSetAux
  line_segment_cut_set_user_object = 'moving_line_segments'
  variable = ls
[../]

/opt/civet/build_0/moose/modules/xfem/test/tests/moving_interface/phase_transition.i

[GlobalParams]
  order = FIRST
  family = LAGRANGE
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 11
  ny = 1
  xmin = 0
  xmax = 2
  ymin = 0
  ymax = 1
  elem_type = QUAD4
[]

[XFEM]
  qrule = volfrac
  output_cut_plane = true
[]

[UserObjects]
  [./velocity]
    type = XFEMPhaseTransitionMovingInterfaceVelocity
    diffusivity_at_positive_level_set = 5
    diffusivity_at_negative_level_set = 1
    equilibrium_concentration_jump = 1
    value_at_interface_uo = value_uo
  [../]
  [./value_uo]
    type = PointValueAtXFEMInterface
    variable = 'u'
    geometric_cut_userobject = 'moving_line_segments'
    execute_on = 'nonlinear'
    level_set_var = ls
  [../]
  [./moving_line_segments]
    type = MovingLineSegmentCutSetUserObject
    cut_data = '0.5 0 0.5 1.0 0 0'
    heal_always = true
    interface_velocity = velocity
  [../]
[]

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

[ICs]
  [./ic_u]
    type = FunctionIC
    variable = u
    function = 'if(x<0.51, 2, 1)'
  [../]
[]

[AuxVariables]
  [./ls]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Constraints]
  [./u_constraint]
    type = XFEMEqualValueAtInterface
    geometric_cut_userobject = 'moving_line_segments'
    use_displaced_mesh = false
    variable = u
    value = 2
    alpha = 1e5
  [../]
[]

[Kernels]
  [./diff]
    type = MatDiffusion
    variable = u
    diffusivity = diffusion_coefficient
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[AuxKernels]
  [./ls]
    type = LineSegmentLevelSetAux
    line_segment_cut_set_user_object = 'moving_line_segments'
    variable = ls
  [../]
[]

[Materials]
  [./diffusivity_A]
    type = GenericConstantMaterial
    prop_names = A_diffusion_coefficient
    prop_values = 5
  [../]
  [./diffusivity_B]
    type = GenericConstantMaterial
    prop_names = B_diffusion_coefficient
    prop_values = 1
  [../]
  [./diff_combined]
    type = LevelSetBiMaterialReal
    levelset_positive_base = 'A'
    levelset_negative_base = 'B'
    level_set_var = ls
    prop_name = diffusion_coefficient
  [../]
[]

[BCs]
# Define boundary conditions
  [./left_u]
    type = DirichletBC
    variable = u
    value = 2
    boundary = 3
  [../]

  [./right_u]
    type = NeumannBC
    variable = u
    boundary = 1
    value = 0
  [../]
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  line_search = 'none'

  l_tol = 1e-3
  nl_max_its = 15
  nl_rel_tol = 1e-12
  nl_abs_tol = 1e-11

  start_time = 0.0
  dt = 0.01
  num_steps = 4
  max_xfem_update = 1
[]

[Outputs]
  execute_on = timestep_end
  exodus = true
  perf_graph = true
  [./console]
    type = Console
    output_linear = true
  [../]
  csv = true
[]

Input Parameters

variableThe name of the variable that this object applies to
C++ Type:AuxVariableName
Options:
Description:The name of the variable that this object applies to

Required Parameters

blockThe list of block ids (SubdomainID) that this object will be applied
C++ Type:std::vector
Options:
Description:The list of block ids (SubdomainID) that this object will be applied
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
execute_onLINEAR TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM, PRE_DISPLACE.
Default:LINEAR TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE INITIAL LINEAR NONLINEAR TIMESTEP_END TIMESTEP_BEGIN FINAL CUSTOM PRE_DISPLACE
Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM, PRE_DISPLACE.
line_segment_cut_set_user_objectName of GeometricCutUserObject that gives the line segments information.
C++ Type:UserObjectName
Options:
Description:Name of GeometricCutUserObject that gives the line segments information.

Optional Parameters

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.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Options:
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
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.

Advanced Parameters

Input Files

modules/xfem/test/tests/moving_interface/phase_transition.i

modules/xfem/test/tests/moving_interface/phase_transition.i

[GlobalParams]
  order = FIRST
  family = LAGRANGE
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 11
  ny = 1
  xmin = 0
  xmax = 2
  ymin = 0
  ymax = 1
  elem_type = QUAD4
[]

[XFEM]
  qrule = volfrac
  output_cut_plane = true
[]

[UserObjects]
  [./velocity]
    type = XFEMPhaseTransitionMovingInterfaceVelocity
    diffusivity_at_positive_level_set = 5
    diffusivity_at_negative_level_set = 1
    equilibrium_concentration_jump = 1
    value_at_interface_uo = value_uo
  [../]
  [./value_uo]
    type = PointValueAtXFEMInterface
    variable = 'u'
    geometric_cut_userobject = 'moving_line_segments'
    execute_on = 'nonlinear'
    level_set_var = ls
  [../]
  [./moving_line_segments]
    type = MovingLineSegmentCutSetUserObject
    cut_data = '0.5 0 0.5 1.0 0 0'
    heal_always = true
    interface_velocity = velocity
  [../]
[]

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

[ICs]
  [./ic_u]
    type = FunctionIC
    variable = u
    function = 'if(x<0.51, 2, 1)'
  [../]
[]

[AuxVariables]
  [./ls]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Constraints]
  [./u_constraint]
    type = XFEMEqualValueAtInterface
    geometric_cut_userobject = 'moving_line_segments'
    use_displaced_mesh = false
    variable = u
    value = 2
    alpha = 1e5
  [../]
[]

[Kernels]
  [./diff]
    type = MatDiffusion
    variable = u
    diffusivity = diffusion_coefficient
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[AuxKernels]
  [./ls]
    type = LineSegmentLevelSetAux
    line_segment_cut_set_user_object = 'moving_line_segments'
    variable = ls
  [../]
[]

[Materials]
  [./diffusivity_A]
    type = GenericConstantMaterial
    prop_names = A_diffusion_coefficient
    prop_values = 5
  [../]
  [./diffusivity_B]
    type = GenericConstantMaterial
    prop_names = B_diffusion_coefficient
    prop_values = 1
  [../]
  [./diff_combined]
    type = LevelSetBiMaterialReal
    levelset_positive_base = 'A'
    levelset_negative_base = 'B'
    level_set_var = ls
    prop_name = diffusion_coefficient
  [../]
[]

[BCs]
# Define boundary conditions
  [./left_u]
    type = DirichletBC
    variable = u
    value = 2
    boundary = 3
  [../]

  [./right_u]
    type = NeumannBC
    variable = u
    boundary = 1
    value = 0
  [../]
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  line_search = 'none'

  l_tol = 1e-3
  nl_max_its = 15
  nl_rel_tol = 1e-12
  nl_abs_tol = 1e-11

  start_time = 0.0
  dt = 0.01
  num_steps = 4
  max_xfem_update = 1
[]


[Outputs]
  execute_on = timestep_end
  exodus = true
  perf_graph = true
  [./console]
    type = Console
    output_linear = true
  [../]
  csv = true
[]

References

Description
Example Input File Syntax
Input Parameters
Input Files
References

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Physics and Syntax

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