LevelSetCutUserObject

XFEM mesh cut by level set function

Overview

This userobject, LevelSetCutUserObject uses a level set field to cut the finite element mesh. The zero level set contour represents the interface.

Example Input File Syntax

[./level_set_cut_uo]
  type = LevelSetCutUserObject
  level_set_var = ls
[../]

Input Parameters

level_set_varThe name of level set variable used to represent the interface
C++ Type:VariableName
Options:
Description:The name of level set variable used to represent the interface

Required Parameters

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Options:
Description:The list of blocks (ids or names) that this object will be applied
execute_onXFEM_MARKThe 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, XFEM_MARK.
Default:XFEM_MARK
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM, XFEM_MARK
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, XFEM_MARK.
heal_alwaysFalseHeal previous cuts at every time step
Default:False
C++ Type:bool
Options:
Description:Heal previous cuts at every time step
negative_id0The CutSubdomainID corresponding to a non-positive signed distance
Default:0
C++ Type:unsigned int
Options:
Description:The CutSubdomainID corresponding to a non-positive signed distance
positive_id1The CutSubdomainID corresponding to a positive signed distance
Default:1
C++ Type:unsigned int
Options:
Description:The CutSubdomainID corresponding to a positive signed distance
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
Options:
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.

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<std::string>
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.
force_postauxFalseForces the UserObject to be executed in POSTAUX
Default:False
C++ Type:bool
Options:
Description:Forces the UserObject to be executed in POSTAUX
force_preauxFalseForces the UserObject to be executed in PREAUX
Default:False
C++ Type:bool
Options:
Description:Forces the UserObject to be executed in PREAUX
force_preicFalseForces the UserObject to be executed in PREIC during initial setup
Default:False
C++ Type:bool
Options:
Description:Forces the UserObject to be executed in PREIC during initial setup
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

(moose/modules/xfem/test/tests/diffusion_xfem/levelsetcut2d_aux.i)

# 2D: Mesh is cut by level set based cutter
# The level set is a MOOSE auxvariable

[GlobalParams]
  order = FIRST
  family = LAGRANGE
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 3
  ny = 3
  xmin = 0
  xmax = 1
  ymin = 0
  ymax = 1
  elem_type = QUAD4
[]

[XFEM]
  qrule = volfrac
  output_cut_plane = true
[]

[UserObjects]
  [./level_set_cut_uo]
    type = LevelSetCutUserObject
    level_set_var = ls
  [../]
[]

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

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

[AuxKernels]
  [./ls_function]
    type = FunctionAux
    variable = ls
    function = ls_func
  [../]
[]

[Functions]
  [./u_left]
    type = PiecewiseLinear
    x = '0   2'
    y = '3   5'
  [../]
  [./ls_func]
    type = ParsedFunction
    value = 'x-0.5'
  [../]
[]

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

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

  [./right_u]
    type = DirichletBC
    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-10
  nl_abs_tol = 1e-10

  start_time = 0.0
  dt = 1
  end_time = 1.0
  max_xfem_update = 1
[]

[Outputs]
  interval = 1
  execute_on = timestep_end
  exodus = true
  [./console]
    type = Console
    output_linear = true
  [../]
[]

Overview
Example Input File Syntax
Input Parameters