ConstantDamper

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

A constant damping factor may improve stability but will slow down convergence of the simulation. More advanced dampers, which taper off through the iterations or which damp less within a certain domain (such as the BoundingValueNodalDamper) should impact less convergence properties.

More information about dampers may be found on the Dampers syntax documentation.

Example input syntax

In this example, a constant damping factor of 0.9 is applied on all variables (just u here).

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

Input Parameters

dampingThe percentage (between 0 and 1) of the newton update to take.
C++ Type:double
Controllable:No
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
Controllable:No
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>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.

Advanced Parameters

(../moose/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
[]