AdamsPredictor

Implements an explicit Adams predictor based on two old solution vectors.

An Adams predictor is automatically added by MOOSE for the AB2PredictorCorrector time stepping/integration scheme.

The formula for the update by Adams' predictor is:

with \phi being the solution vector, including all degrees of freedom for the nonlinear variables and

with , and being the current, previous and antepenultimate time steps sizes.

Example input syntax

In this example, an AdamsPredictor is implicitly being created by specifying the AB2PredictorCorrector time stepping scheme. The predictor is being used on every time step to perform a first update step.

[Executioner]
  type = Transient
  scheme = 'BDF2'
  #scheme = 'crank-nicolson'
  start_time = 0
  num_steps = 4
  nl_abs_tol = 1e-15
  petsc_options = '-snes_converged_reason'
  abort_on_solve_fail = true
  [./TimeStepper]
    type = AB2PredictorCorrector
    dt = .01
    e_max = 10
    e_tol = 1
  [../]
[]
(test/tests/time_integrators/aee/aee.i)

Input Parameters

  • scaleThe scale factor for the predictor (can range from 0 to 1)

    C++ Type:double

    Controllable:No

    Description:The scale factor for the predictor (can range from 0 to 1)

Required Parameters

  • nl_sysnl0The nonlinear system that this predictor should be applied to.

    Default:nl0

    C++ Type:NonlinearSystemName

    Controllable:No

    Description:The nonlinear system that this predictor should be applied to.

  • order2The maximum reachable order of the Adams-Bashforth Predictor

    Default:2

    C++ Type:int

    Controllable:No

    Description:The maximum reachable order of the Adams-Bashforth Predictor

  • skip_after_failed_timestepFalseSkip prediction in a repeated time step after a failed time step

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Skip prediction in a repeated time step after a failed time step

  • skip_timesSkip the predictor if the current solution time is in this list of times

    C++ Type:std::vector<double>

    Controllable:No

    Description:Skip the predictor if the current solution time is in this list of times

  • skip_times_oldSkip the predictor if the previous solution time is in this list of times

    C++ Type:std::vector<double>

    Controllable:No

    Description:Skip the predictor if the previous solution time is in this list of times

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:No

    Description:Set the enabled status of the MooseObject.

Advanced Parameters