NONNC

Recognised by the OPM Flow parserRUNSPEC

The NONNC keyword deactivates non-neighbor connections (“NNCs”) in the current run. NNCs create off-diagonal elements in the Jacobi matrix that impact the numerical efficiency of the solution algorithms, and thus if the run does not contain NNCs then there is the potential for greater computation efficiency. Unfortunately, nearly all models, except for the most simple models, generate NNCs via for example:

aquifer connections,

faults, and

manually entered NNCs, including those automatically generate by pre-processing software.

There is no data required for this keyword and there is no terminating “/” for this keyword.

Records

No records — the keyword stands alone

Example

--
-- DEACTIVATE NON-NEIGHBOR CONNECTIONS
--
NONNC
The above example switches off the NNCs.

Manual source: parts/chapters/subsections/5.3/NONNC.fodt