With FEFLOW, I experienced stability problems with models with
- an irregular mesh --> try the Smooth mesh tool;
- too high conductivity differences (elements with 10-8 m/s conductivity
adiacent to ones with 10-3 m/s) --> do what you can to "smooth" the conductivity
distribution.

May the 200 days of maximum time steps be tied to the power functions governing
the transient conditions? Considering you are simulating 10000 years... Good
luck!

Giovanni Formentin





--- In feflow@..., Giovanna Monti <giovanna.monti@...> wrote:
>
> Hi,
>
> There are problems of stability.
> You should check the model before running it.
>
> I suggest a couple of checks:
>
>  at first run the model in steady state and check if it converges and that the
balance (IN-OUT) is fine for your problem, otherwise you have to control your
input, the number of layers vs deep, mesh etc
> then I would rehash the steady state solution and I would run the new model in
transient conditionif that does not work, I would check again the mesh near well
points and verify how the model works without wells.Hoping this will help you!
>
> Don't quit!
>
> Giovanna Monti
> environmental engineer
> Washington DC
>
>
> --- Mer 13/5/09, manish_cjonty2006 <manish_cjonty2006@...> ha scritto:
>
> Da: manish_cjonty2006 <manish_cjonty2006@...>
> Oggetto: [feflow] to reduce model run time
> A: feflow@...
> Data: Mercoledì 13 maggio 2009, 12:42
>
>
> Hello everyone...
>
> I am doing groundwater flow and contaminant transport modeling for saturated
region with transient conditions. I am doing it for 1.0xE4 years. while doing
that i am facing two problems
>
> 1.Head values at some of the observation wells are oscillating 10-15 metres
>
> 2.Time step is not going beyond 200 days so it is taking so much time for
running. I am using automatic predictor corrector method.
>
> i would like you all to give your suggestions so that i can resolve thee
problems.
>
> Thanks.
>
> Regards,
> Manish Chopra
>