HYSTE

HYSTE (optional) provides numerical controls on the hysteretic characteristic curves. It is not needed if the default values of all its parameters are to be used.

Record HYSTE.1

Free format for 3 parameters, or Format(3I5).

IEHYS(I), I=1,3

IEHYS(1) flag to print information about hysteretic characteristic curves.

=0 no additional print out.

≥1 print a one-line message to the output file every time a capillary-pressure branch switch occurs (recommended).

IEHYS(2) flag indicating when to apply capillary-pressure branch switching.

=0 after convergence of time step (recommended).

>0 after each Newton-Raphson iteration.

IEHYS(3) run parameter for sub-threshold saturation change.

=0 no branch switch unless |∆S| > CP(10).

>0 allow branch switch after run of IEHYS(3) consecutive time steps for which all |∆S| < CP(10) and all ∆S are the same sign. Recommended value 5-10. This option may be useful if the time step is cut to a small value due to convergence problems, making saturation changes very small.

The IEHYS(1)-IEHYS(3) can also be inputted through IE(5), IE(6) and IE(7), if the hysteresis function is on.

Used in: All EOS modules

Example:

HYSTE

0, 1, 0