Manual Page for Command >>> REDUCTION


Syntax
>>> REDUCTION: max_red

Parent Command
>> CONVERGE

Subcommand
-

Description
By default, a TOUGH2 simulation stops if 20 consecutive time step reductions have occurred without convergence. This command changes the maximum number of allowable time step reductions to max_red. Time step reductions occur if:

(1) the initial time step is too large (see TOUGH2 variable DELTEN or DLT(1), and command >>> ADJUST);
(2) TOUGH2 parameter NOITE is too small;
(3) a failure in the EOS module occurs ;
(4) boundary conditions are changed drastically during the course of the simulation.

Variable max_red should only be increased to address problem (4), i.e., when drastic changes in generation rates (TOUGH2 block GENER) are imposed, or if Dirichlet boundary conditions are changed using command >> RESTART TIME or through subroutine USERBC.

Example
> COMPUTATION
>> CONVERGE
>>> accept : 30 CONSECUTIVE time step reductions
<<<
<<

See Also
>> RESTART TIME | >>> ADJUST | >>> CONSECUTIVE


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Page updated: July 29, 1997