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TIMESTEPPER

Specifies time step acceleration, maximum number of time steps, etc.

Required Cards:

TIMESTEPPER <string>
Specifies the type of timestepper, where <string> is FLOW or TRANSPORT.

Optional Cards:

NUM_STEPS_AFTER_CUT <int>
Number of time steps after a time step cut that the time step size must be held constant
MAX_STEPS <int>
Maximum time step after which the simulation will be terminated
TS_ACCELERATION <int>
Integer indexing time step acceleration ramp (expert users only). Use in conjunction with DT_FACTOR.
MAX_TS_CUTS <int>
Maximum number of consecutive time step cuts before the simulation is terminated with plot of the current solution printed to a XXX_cut_to_failure.tec file for debugging.
DT_FACTOR <float array>
Array of floating point numbers of tfac array (expert users only). Values specify time step multiplier as a function of number of Newton iterations in consecutive order from 1 Newton iteration to TS_ACCELERATION Newton iterations.
TIMESTEP_REDUCTION_FACTOR <float>
The factor by which the time step will be reduced when it is cut (default: 0.5).
TIMESTEP_MAXIMUM_GROWTH_FACTOR <float>
The maximum factor by which the time step can be increased between time steps (default: 2.).
INITIALIZE_TO_STEADY_STATE
Flag requesting that a steady state solution be computed based on boundary and initial conditions at the beginning of the simulation (Warning: not robust)
RUN_AS_STEADY_STATE
Flag indicating that the simulation is to be run as steady state (Warning: not robust)

Examples

TIMESTEPPER FLOW
  TS_ACCELERATION 8
  MAX_STEPS 10000  ! terminates simulation after 10,000 time steps
  MAX_TS_CUTS 5    ! terminates simulation after 5 consecutive time step cuts
END