This solved the problem, thanks a lot Bernd!!!
From: Bernd Flemisch <[email protected]>
To: DuMuX User Forum <[email protected]>
Sent: Monday, March 26, 2012 12:45 PM
Subject: Re: [DuMuX] Permeability heterogeneity and grid resolution
Hey Shawn,
here, it helps to change the linear solver (or rather the preconditioner from
ILU to SSOR). This unfortunately is a compile-time choice done in the problem
file. I attach my corresponding problem file, changes are in lines 83 and 86.
Kind regards
Bernd
On Mon, 26 Mar 2012 09:00:18 -0700 (PDT)
Shawn Zhang <[email protected]> wrote:
> Hi Bernd,
>
> I switched the permeability between lens and outside, which gives the
> non-convergence exception.
>
> I.e.,
>
> permeability = 1e-12
> permeabilityLens = 1e-10
>
> Instead of
>
>
> From: Bernd Flemisch <[email protected]>
> To: DuMuX User Forum <[email protected]> Sent: Monday, March
> 26, 2012 11:08 AM
> Subject: Re: [DuMuX] Permeability heterogeneity and grid resolution
>
> Hey Shawn,
>
> ok, this is difficult since I cannot reproduce it. Can you please send the
> output of your run with 100x100 and the attached input file? I increased the
> verbosity of the linear solver, so maybe we can see more from there.
>
> Kind regards
> Bernd
>
>
> On Mon, 26 Mar 2012 07:53:03 -0700 (PDT)
> Shawn Zhang <[email protected]> wrote:
>> Hi Bernd,
>>
>> Thanks a lot for your quick attention. However, with your input file, and
>> grid resolution 100x100, I got the same exceptions. I also tried to increase
>> ResidualReduction parameter even further without any luck.
>>
>> It puzzles me that the code runs at lower resolution but not at higher...
>>
>> -Shawn
>>
>> From: Bernd Flemisch <[email protected]>
>> To: DuMuX User Forum <[email protected]> Sent: Saturday, March
>> 24, 2012 6:07 AM
>> Subject: Re: [DuMuX] Permeability heterogeneity and grid resolution
>>
>> Hey Shawn,
>>
>> thank you for reporting this. It helps to relax the threshold for the
>> reduction of the residual that the linear solver is required to achieve. I
>> attach a corresponding input file, where the parameter is adjusted in line
>> 31.
>>
>> To me, the default threshold of 1e-12 seems to be very small. We will
>> discuss whether the default value should be adjusted.
>>
>> Kind regards
>> Bernd
>>
>> On Fri, 23 Mar 2012 12:36:05 -0700 (PDT)
>> Shawn Zhang <[email protected]> wrote:
>>> Dear All,
>>>
>>> I ran into an issue of 1p model not converging. After a series of tests, I
>>> trace it to this canonical situation,
>>> For standard test/boxmodels/1p problem, if I increase the 2D grid
>>> resolution from 10x10 to 100x100, the solver will not converge, with the
>>> following error reported.
>>>
>>> This error, however, will go away if I reduce the perm difference between
>>> lens and exterior from 2 order of magnitude into 1 order of magnitude. This
>>> makes me speculate that the error is related to sharp gradient at
>>> lens/exterior interface caused by the heterogeneity at high resolution.
>>>
>>> I think the reproducer on standard test makes it likely a serious problem,
>>> though I will be very happily corrected.
>>>
>>> Truly appreciate your quick attention.
>>>
>>> Best,
>>> -Shawn
>>>
>>> root@szdebian:/home/szhang/dumux/dumux-2.1.0/test/boxmodels/1p# ./test_1p
>>> -parameterFile test_1p.input
>>> Welcome aboard DuMuX airlines. Please fasten your seatbelts! Emergency
>>> exits are near the time integration.
>>> Initializing problem '1ptest'
>>> Writing result file for "1ptest"
>>> Newton iteration 1 done, relative error = 0.666666
>>> Newton iteration 2 done, relative error = 5.45083e-06
>>> Solve: M deltax^k = rNewton: Caught exception: "NumericalProblem
>>> [newtonSolveLinear:../../../dumux/nonlinear/newtoncontroller.hh:398]:
>>> Linear solver did not converge"
>>> Newton solver did not converge with dt=1 seconds. Retrying with time step
>>> of 0.5 seconds
>>> Newton iteration 1 done, relative error = 0.666666
>>> Newton iteration 2 done, relative error = 5.45083e-06
>>> Solve: M deltax^k = rNewton: Caught exception: "NumericalProblem
>>> [newtonSolveLinear:../../../dumux/nonlinear/newtoncontroller.hh:398]:
>>> Linear solver did not converge"
>>>
>>> ....
>>> Newton solver did not converge with dt=0.0078125 seconds. Retrying with
>>> time step of 0.00390625 seconds
>>> Newton iteration 1 done, relative error = 0.666666
>>> Newton iteration 2 done, relative error = 5.45083e-06
>>> Solve: M deltax^k = rNewton: Caught exception: "NumericalProblem
>>> [newtonSolveLinear:../../../dumux/nonlinear/newtoncontroller.hh:398]:
>>> Linear solver did not converge"
>>> Newton solver did not converge with dt=0.00390625 seconds. Retrying with
>>> time step of 0.00195312 seconds
>>> Newton iteration 1 done, relative error = 0.666666
>>> Newton iteration 2 done, relative error = 5.45083e-06
>>> Solve: M deltax^k = rNewton: Caught exception: "NumericalProblem
>>> [newtonSolveLinear:../../../dumux/nonlinear/newtoncontroller.hh:398]:
>>> Linear solver did not converge"
>>> Newton solver did not converge with dt=0.00195312 seconds. Retrying with
>>> time step of 0.000976562 seconds
>>> Dune reported error: Dune::MathError
>>> [timeIntegration:../../../dumux/boxmodels/common/boxproblem.hh:485]: Newton
>>> solver didn't converge after 10 time-step divisions. dt=0.000976562
>>
>> ___________________________________________________________
>>
>> Bernd Flemisch phone: +49 711 685 69162
>> IWS, Universitaet Stuttgart fax: +49 711 685 67020
>> Pfaffenwaldring 61 email: [email protected]
>> D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de
>> ___________________________________________________________
>>
>> _______________________________________________
>> Dumux mailing list
>> [email protected]
>> https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
>
> ___________________________________________________________
>
> Bernd Flemisch phone: +49 711 685 69162
> IWS, Universitaet Stuttgart fax: +49 711 685 67020
> Pfaffenwaldring 61 email: [email protected]
> D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de
> ___________________________________________________________
>
> _______________________________________________
> Dumux mailing list
> [email protected]
> https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
>
>
>
> permeability = 1e-10
> permeabilityLens = 1e-12
>
> Sorry about the ignorance. I should notice this the first time. Can you give
> a try and see whether you can reproduce?
>
> -Shawn
___________________________________________________________
Bernd Flemisch phone: +49 711 685 69162
IWS, Universitaet Stuttgart fax: +49 711 685 67020
Pfaffenwaldring 61 email: [email protected]
D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de
___________________________________________________________
_______________________________________________
Dumux mailing list
[email protected]
https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
_______________________________________________
Dumux mailing list
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https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
