XFEMPhaseTransitionMovingInterfaceVelocity

calculate the interface velocity for a simple phase transition problem.

Description

The XFEMPhaseTransitionMovingInterfaceVelocity calculates an interface velocity that is given as $var element = document.getElementById("moose-equation-cd3e4897-fc46-4304-824a-ca77e759a6cb");katex.render("v = \\frac{[[ {D}\\nabla {u}\\cdot\\text{n}]]}{[[ {u}]] + u_0}", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ . The current implementation only supports the case in which the interface is moving horizontally.

Example Input File Syntax

[./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
[../]

/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

diffusivity_at_negative_level_setDiffusivity for level set negative region.
C++ Type:double
Options:
Description:Diffusivity for level set negative region.
diffusivity_at_positive_level_setDiffusivity for level set positive region.
C++ Type:double
Options:
Description:Diffusivity for level set positive region.
equilibrium_concentration_jumpThe jump of the equilibrium concentration at the interface.
C++ Type:double
Options:
Description:The jump of the equilibrium concentration at the interface.
value_at_interface_uoThe name of the userobject that obtains the value and gradient at the interface.
C++ Type:UserObjectName
Options:
Description:The name of the userobject that obtains the value and gradient at the interface.

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

Optional Parameters

allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
Default:False
C++ Type:bool
Options:
Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
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.
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
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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