ConstantDamper

construction:Undocumented Class

The ConstantDamper has not been documented. The content listed below should be used as a starting point for documenting the class, which includes the typical automatic documentation associated with a MooseObject; however, what is contained is ultimately determined by what is necessary to make the documentation clear for users.


# ConstantDamper

!syntax description /Dampers/ConstantDamper

## Overview

!! Replace these lines with information regarding the ConstantDamper object.

## Example Input File Syntax

!! Describe and include an example of how to use the ConstantDamper object.

!syntax parameters /Dampers/ConstantDamper

!syntax inputs /Dampers/ConstantDamper

!syntax children /Dampers/ConstantDamper

Modifies the non-linear step by applying a constant damping factor.

Input Parameters

dampingThe percentage (between 0 and 1) of the newton update to take.
C++ Type:double
Options:
Description:The percentage (between 0 and 1) of the newton update to take.

Required Parameters

min_damping0Minimum value of computed damping. Damping lower than this will result in an exception being thrown and cutting the time step
Default:0
C++ Type:double
Options:
Description:Minimum value of computed damping. Damping lower than this will result in an exception being thrown and cutting the time step

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.

Advanced Parameters

Input Files

(test/tests/dampers/constant_damper/constant_damper_test.i)
(test/tests/dampers/min_damping/min_general_damping.i)
(test/tests/controls/time_periods/error/control.i)
(test/tests/controls/time_periods/aux_scalar_kernels/enable_disable.i)
(test/tests/controls/time_periods/dampers/control.i)
(test/tests/controls/time_periods/aux_kernels/enable_disable.i)
(examples/ex19_dampers/ex19.i)
(test/tests/controls/time_periods/error/steady_error.i)
(test/tests/controls/time_periods/dampers/enable_disable.i)

(test/tests/dampers/constant_damper/constant_damper_test.i)

[Mesh]
  [./square]
    type = GeneratedMeshGenerator
    nx = 2
    ny = 2
    dim = 2
  [../]
[]

[Variables]
  active = 'u'

  [./u]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Kernels]
  active = 'diff'

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

[BCs]
  active = 'left right'

  [./left]
    type = DirichletBC
    variable = u
    boundary = 3
    value = 0
  [../]

  [./right]
    type = DirichletBC
    variable = u
    boundary = 1
    value = 1
  [../]
[]

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Executioner]
  type = Steady
  solve_type = 'PJFNK'
[]

[Outputs]
  file_base = out
  exodus = true
[]

(test/tests/dampers/min_damping/min_general_damping.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
[]

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

[Kernels]
  [./u_dt]
    type = TimeDerivative
    variable = u
  [../]
  [./u_source]
    type = BodyForce
    variable = u
    value = 1
  [../]
[]

[Dampers]
  [./limit]
    type = ConstantDamper
    damping = 0.25
    min_damping = 0.5
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 2
  dt = 1.0
  dtmin = 0.5
[]

[Postprocessors]
  [./u_avg]
    type = ElementAverageValue
    variable = u
  [../]
  [./dt]
    type = TimestepSize
  [../]
[]

(test/tests/controls/time_periods/error/control.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.1
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
[]

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
[]

[Controls]
  [./damping_control]
    type = TimePeriod
    disable_objects = 'const_damp'

    # Note: These numbers are quoted to get around an issue when
    # overriding numeric types with vectors of numeric types
    # on the CLI. They are still interpreted as numbers.
    start_time = '0.25'
    end_time = '0.55'
    execute_on = 'initial timestep_begin'
  [../]
[]

(test/tests/controls/time_periods/aux_scalar_kernels/enable_disable.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

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

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

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

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
  exodus = true
[]

(test/tests/controls/time_periods/dampers/control.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 5
  dt = 0.1
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  nl_rel_tol = 0.95e-8
[]

[Postprocessors]
  [./nlin]
    type = NumNonlinearIterations
  [../]
[]

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
  csv = true
[]

[Controls]
  [./damping_control]
    type = TimePeriod
    disable_objects = '*::const_damp'
    start_time = 0.25
    execute_on = 'initial timestep_begin'
  [../]
[]

(test/tests/controls/time_periods/aux_kernels/enable_disable.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

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

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

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

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
  exodus = true
[]

(examples/ex19_dampers/ex19.i)

[Mesh]
  type = GeneratedMesh
  dim = 2

  xmin = 0.0
  xmax = 1.0
  nx = 10

  ymin = 0.0
  ymax = 1.0
  ny = 10
[]

[Variables]
  [./diffusion]
    order = FIRST
    family = LAGRANGE
  [../]
[]

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

[BCs]
  [./left]
    type = DirichletBC
    variable = diffusion
    boundary = 3
    value = 3
  [../]

  [./right]
    type = DirichletBC
    variable = diffusion
    boundary = 1
    value = 1
  [../]
[]

[Dampers]
  # Use a constant damping parameter
  [./diffusion_damp]
    type = ConstantDamper
    variable = diffusion
    damping = 0.9
  [../]
[]

[Executioner]
  type = Steady

  #Preconditioned JFNK (default)
  solve_type = 'PJFNK'
[]

[Outputs]
  exodus = true
[]

(test/tests/controls/time_periods/error/steady_error.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
#  The TimeDerivative existing in a Steady calculation will trigger an error itself!
#  [./time]
#    type = TimeDerivative
#    variable = u
#  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

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

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
  exodus = true
[]

[Controls]
  [./damping_control]
    type = TimePeriod
    disable_objects = 'const_damp'
    start_time = 0.25
    execute_on = 'initial timestep_begin'
  [../]
[]

(test/tests/controls/time_periods/dampers/enable_disable.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

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

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

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  [../]
[]

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

[Dampers]
  [./const_damp]
    type = ConstantDamper
    damping = 0.9
  [../]
[]

[Outputs]
  exodus = true
[]

Input Parameters
Input Files

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