Specifies nonlinear solver parameters associated with the simulation. An example is as follows:
NEWTON_SOLVER FLOW ATOL 1D-8 RTOL 1D-8 STOL 1D-30 END
An example showing all possible options is:
NEWTON_SOLVER FLOW NO_INFINITY_NORM NO_FORCE_ITERATION NO_PRINT_CONVERGENCE PRINT_DETAILED_CONVERGENCE ATOL 1D-8 RTOL 1D-8 STOL 1D-30 ITOL 1D-6 ITOL_S 1D-6 ITOL_UPDATE 1D-6 MAXIT 10 MAXF 50 MATRIX_TYPE AIJ PRECONDITIONER_MATRIX_TYPE AIJ END
The variables in the keywords above have the following meanings:
Can be FLOW or TRANSPORT. For TOIL_IMS, GAS_WATER, BLACK_OIL, TODD_LONGSTAFF and SOLVENT_TL, this must be FLOW.
If included, toggles off calculation of infinity norm on residual and update vectors. The default is to calculate infinity norm.
If included toggles off the forcing of at least 1 linear iteration. The default is to force at least 1 linear iteration.
If included, prints convergence information.
If included, printing of detailed convergence information.
Absolute tolerance. Absolute size of 2-norm of residual.
Relative tolerance. Relative decrease in size of 2-norm of residual.
Relative update tolerance. Relative decrease in size of 2-norm of solution
Note: STOL needs to be treated with great caution, as it simply accepts the step when then solution updates fall below the specified criteria, and this may allow badly unconverged steps to be accepted. It is recommended that STOL be set very low (e.g. 1.0D-30, as in the examples above) so that this cannot happen
Infinity tolerance. Size of infinity norm of residual.
Infinity tolerance. Size of infinity norm of scaled residual.
Infinity tolerance. Size of infinity norm of update
Maximum number of Newton iterations before reporting failed convergence.
Maximum number of function evaluations before reporting failed convergence.
Format of main solver matrix. PETSc Mat (i.e. AIJ, BAIJ, or HYPRESTRUCT).
Format of preconditioning matrix. Default is same as solver.