SimpleACInterface

Gradient energy for Allen-Cahn Kernel with constant Mobility and Interfacial parameter

note

This kernel is part of a set of simplified phase field kernels that have been created for educational purposes. These kernels use simplified formulations with limitations that prohibit spatially varying mobilities and gradient energies. The source code of these kernels is kept simple without using advanced C++ features.

This kernel implements the weak form $var element = document.getElementById("moose-equation-0d8c9874-4b11-4095-aa0f-60ea4dc65223");katex.render("(\\kappa L \\nabla u, \\nabla\\psi)", element, {displayMode:true,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ for the gradient contribution in the Allen-Cahn equation. For a more feature complete version see the ACInterface kernel, which allows for variable dependent mobilities $var element = document.getElementById("moose-equation-16936491-ea4a-41a8-9934-08d939aa1b19");katex.render("M", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ and gradient energy parameters $var element = document.getElementById("moose-equation-8c645b75-16fc-480a-a1b4-ac1039058872");katex.render("\\kappa", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ .

Input Parameters

variableThe name of the variable that this Kernel operates on
C++ Type:NonlinearVariableName
Options:
Description:The name of the variable that this Kernel operates on

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
displacementsThe displacements
C++ Type:std::vector
Options:
Description:The displacements
kappa_namekappa_opThe kappa used with the kernel
Default:kappa_op
C++ Type:MaterialPropertyName
Options:
Description:The kappa used with the kernel
mob_nameLThe mobility used with the kernel
Default:L
C++ Type:MaterialPropertyName
Options:
Description:The mobility used with the kernel

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.
diag_save_inThe name of auxiliary variables to save this Kernel'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
Options:
Description:The name of auxiliary variables to save this Kernel'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
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
save_inThe name of auxiliary variables to save this Kernel'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
Options:
Description:The name of auxiliary variables to save this Kernel'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
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

extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector
Options:
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
Options:
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
Options:nontime system
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
Options:nontime time
Description:The tag for the vectors this Kernel should fill

Tagging Parameters

Input Files

modules/phase_field/test/tests/SimpleACInterface/SimpleACInterface.i

modules/phase_field/test/tests/SimpleACInterface/SimpleACInterface.i

#
# Test the parsed function free enery Allen-Cahn Bulk kernel
#

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 20
  ny = 20
  nz = 0
  xmin = 0
  xmax = 50
  ymin = 0
  ymax = 50
  zmin = 0
  zmax = 50
  elem_type = QUAD4

  uniform_refine = 1
[]

[Variables]
  [./eta]
    order = FIRST
    family = LAGRANGE
    [./InitialCondition]
      type = SmoothCircleIC
      x1 = 25.0
      y1 = 25.0
      radius = 6.0
      invalue = 0.9
      outvalue = 0.1
      int_width = 3.0
    [../]
  [../]
[]

[Kernels]
  [./detadt]
    type = TimeDerivative
    variable = eta
  [../]

  [./ACBulk]
    type = AllenCahn
    variable = eta
    f_name = F
  [../]

  [./ACInterface]
    type = SimpleACInterface
    variable = eta
    kappa_name = 1
  [../]
[]

[Materials]
  [./consts]
    type = GenericConstantMaterial
    block = 0
    prop_names  = 'L'
    prop_values = '1'
  [../]

  [./free_energy]
    type = DerivativeParsedMaterial
    block = 0
    f_name = F
    args = 'eta'
    function = '2 * eta^2 * (1-eta)^2 - 0.2*eta'
    derivative_order = 2
  [../]
[]

[Executioner]
  type = Transient
  scheme = 'bdf2'

  solve_type = 'PJFNK'

  l_max_its = 15
  l_tol = 1.0e-4

  nl_max_its = 10
  nl_rel_tol = 1.0e-11

  start_time = 0.0
  num_steps = 2
  dt = 0.5
[]

[Outputs]
  exodus = true
[]

Input Parameters
Input Files

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