DiffusionFluxAux

Compute components of flux vector for diffusion problems $var element = document.getElementById("moose-equation-85b93690-4ec2-4781-a2c3-66844daf0542");katex.render("(\\vv{J} = -D \\nabla C)", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ .

Description

The DiffusionFluxAux AuxKernel is used to compute the components of the flux vector for diffusion problems. The flux is computed as $var element = document.getElementById("moose-equation-ab1125f1-a0e0-484e-b763-e99c0aede0d2");katex.render("", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ J=-D\frac{\partial C}{\partial X} $var element = document.getElementById("moose-equation-645ac944-9b2c-4670-a477-26928cc14980");katex.render("", element, {displayMode:false,throwOnError:false,macros:{"\\pf":"\\frac{\\partial #1}{\\partial #2}"}});$ , where J is the diffusion flux vector, D is the diffusivity or diffusion coefficient, C is the concentration variable, and X is the coordinate.

Input Parameters

componentThe desired component of flux.
C++ Type:MooseEnum
Options:x, y, z, normal
Description:The desired component of flux.
diffusion_variableThe name of the variable
C++ Type:std::vector<VariableName>
Options:
Description:The name of the variable
diffusivityThe name of the diffusivity material property that will be used in the flux computation.
C++ Type:MaterialPropertyName
Options:
Description:The name of the diffusivity material property that will be used in the flux computation.
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 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
boundaryThe list of boundaries (ids or names) from the mesh where this boundary condition applies
C++ Type:std::vector<BoundaryName>
Options:
Description:The list of boundaries (ids or names) from the mesh where this boundary condition applies
check_boundary_restrictedTrueWhether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
Default:True
C++ Type:bool
Options:
Description:Whether to check for multiple element sides on the boundary in the case of a boundary restricted, element aux variable. Setting this to false will allow contribution to a single element's elemental value(s) from multiple boundary sides on the same element (example: when the restricted boundary exists on two or more sides of an element, such as at a corner of a mesh
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.
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

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.
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

(test/tests/auxkernels/diffusion_flux/diffusion_flux.i)
(test/tests/auxkernels/diffusion_flux/normal_diffusion_flux.i)

(test/tests/auxkernels/diffusion_flux/diffusion_flux.i)

[Mesh]
  type = GeneratedMesh # Can generate simple lines, rectangles and rectangular prisms
  dim = 2 # Dimension of the mesh
  nx = 10 # Number of elements in the x direction
  ny = 10 # Number of elements in the y direction
  xmax = 1.0
  ymax = 1.0
[]

[Variables]
  [./T]
  [../]
[]

[AuxVariables]
  [./flux_x]
      order = FIRST
      family = MONOMIAL
  [../]
  [./flux_y]
      order = FIRST
      family = MONOMIAL
  [../]
[]

[Kernels]
  [./diff]
    type = MatDiffusionTest # A Laplacian operator
    variable = T
    prop_name = 'thermal_conductivity'
  [../]
[]

[AuxKernels]
  [./flux_x]
    type = DiffusionFluxAux
    diffusivity = 'thermal_conductivity'
    variable = flux_x
    diffusion_variable = T
    component = x
  [../]
  [./flux_y]
    type = DiffusionFluxAux
    diffusivity = 'thermal_conductivity'
    variable = flux_y
    diffusion_variable = T
    component = y
  [../]
[]

[BCs]
  [./inlet]
    type = DirichletBC # Simple u=value BC
    variable = T
    boundary = left
    value = 4000 # K
  [../]
  [./outlet]
    type = DirichletBC
    variable = T
    boundary = right
    value = 400 # K
  [../]
[]

[Materials]
  [./k]
    type = GenericConstantMaterial
    prop_names = 'thermal_conductivity'
    prop_values = '10' # in W/mK
  [../]
[]

[VectorPostprocessors]
  [./line_sample]
    type = LineValueSampler
    variable = 'T flux_x flux_y'
    start_point = '0 0. 0'
    end_point = '1.0 0. 0'
    num_points = 11
    sort_by = id
  [../]
[]

[Executioner]
  type = Steady # Steady state problem
  solve_type = PJFNK #Preconditioned Jacobian Free Newton Krylov
  nl_rel_tol = 1e-12
  petsc_options_iname = '-pc_type -pc_hypre_type' #Matches with the values below
  petsc_options_value = 'hypre boomeramg'
[]

[Outputs]
  exodus = true # Output Exodus format
  execute_on = 'initial timestep_end'
  csv = true
[]

(test/tests/auxkernels/diffusion_flux/normal_diffusion_flux.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
  xmax = 1.0
  ymax = 1.0
[]

[Variables]
  [./dummy]
  [../]
[]

[AuxVariables]
  [./T]
  [../]
  [./flux_n]
    order = CONSTANT
    family = MONOMIAL
  [../]
[]

[Functions]
  [./T]
    type = ParsedFunction
    value = 'x*x*y*y+1'
  [../]
[]

[ICs]
  [./T]
    type = FunctionIC
    variable = T
    function = T
  [../]
[]

[Kernels]
  [./dummy]
    type = Diffusion
    variable = dummy
  [../]
[]

[AuxKernels]
  [./flux_n]
    type = DiffusionFluxAux
    diffusivity = 'thermal_conductivity'
    variable = flux_n
    diffusion_variable = T
    component = normal
    boundary = 'left right'
    check_boundary_restricted = false
  [../]
[]

[Materials]
  [./k]
    type = GenericConstantMaterial
    prop_names = 'thermal_conductivity'
    prop_values = '10'
  [../]
[]

[Postprocessors]
  [flux_right]
    type = SideIntegralVariablePostprocessor
    variable = flux_n
    boundary = 'right'
  []
  [flux_right_exact]
    type = SideFluxIntegral
    variable = T
    diffusivity = 'thermal_conductivity'
    boundary = 'right'
  []
  [flux_left]
    type = SideIntegralVariablePostprocessor
    variable = flux_n
    boundary = 'left'
  []
  [flux_left_exact]
    type = SideFluxIntegral
    variable = T
    diffusivity = 'thermal_conductivity'
    boundary = 'left'
  []
[]

[Executioner]
  type = Steady
  solve_type = PJFNK
  nl_rel_tol = 1e-12
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
[]

[Outputs]
  exodus = true
  hide = 'dummy'
[]

Description
Input Parameters
Input Files

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