Gio's advice is good. The problem may lie with conflicting boundary
conditions or bc constraints, which may or may not show up in the steady
state. Another possibility is the mode used, phreatic, confined, etc.
"Free and Movable" slices can be unstable. More information is needed to
make useful comments on the actual problem.

*Pete*

www.aquageo.us


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@...
> <mailto:manish_cjonty2006%40yahoo.co.in>> ha scritto:
>
> Da: manish_cjonty2006 <manish_cjonty2006@...
> <mailto:manish_cjonty2006%40yahoo.co.in>>
> Oggetto: [feflow] to reduce model run time
> A: feflow@... <mailto:feflow%40yahoogroups.co.in>
> 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