Hey Shawn,
thank you for your further investigations. You are right
that the options for the linear solver are not well
documented yet. You can choose one out of
dumux/linear/boxlinearsolver.hh. The parameters are
documented in dumux/linear/linearsolverproperties.hh.
About the actual meaning of, e.g., a relaxation parameter
or a preconditioner, you should consider your favorite
linear algebra textbook.
Concerning your 3d calculations: are you using the release
or the trunk? If you use the release, 3d can break, since
the z-coordinate of the lens is not set. You can use the
attached 1ptestspatialparameters.hh. This is already fixed
in the trunk and will be fixed in a bugfix release 2.1.1.
Kind regards
Bernd
On Sat, 31 Mar 2012 19:02:42 -0700 (PDT)
Shawn Zhang <[email protected]> wrote:
Hi Bernd and All,
I confirm that Bernd's input file resolved the
convergence problem I had. Thanks.
However (I hate it when people do this to me, but sorry
I can't find other way out), I am still puzzled by this
convergence issue. It seems the following factors are
influencing the convergence,
1. Resolution. The higher the resolution, the more
difficult the convergence.
2. Heterogeneity. The higher the heterogeneity, the more
difficult the convergence.
3. Linear solver type. Not sure what are the options and
how they are related to convergence.
4. Solve controls: relaxation, preconditioners, and
number of iterations. I only understand the last one.
I most puzzled by #1. Why higher grid resolution causes
non-convergence?
Attached a more specific problem I am working on. The
set up converge at 10x10x10, but diverge at 50x50x50 or
higher.
Would you mind taking a look and suggest how to make it
converge? I need to run it at 200x200x200 resolution.
In addition to the problem, I also modified 1pmodel.hh
file to handle tensor perm. I also have a question about
why using Scalar tensor in all the boxmodels tests, but
this is not critical (unless it is related to the
convergence issue).
Sorry about all the questions, but I am about to pull my
hair now.
-Shawn
From: Bernd Flemisch <[email protected]>
To: DuMuX User Forum <[email protected]>
Sent: Thursday, March 29, 2012 5:23 AM
Subject: Re: [DuMuX] Permeability heterogeneity and grid
resolution
Sorry, wrong file. Attached is the correct one.
Kind regards
On Thu, 29 Mar 2012 10:36:57 +0200
Bernd Flemisch <[email protected]> wrote:
Hey Shawn,
I was not too specific about what to change: you should
set PreconditionerIterations to 3, not
PreconditionerRelaxation. You can also set this in the
input file, it overrides the settings of the problem
file.
I attach my current working input file for your
convenience.
Kind regards
Bernd
On Wed, 28 Mar 2012 12:42:13 -0700 (PDT)
Shawn Zhang <[email protected]> wrote:
Hi Bernd and All,
Sorry if I appear to be sticky about the convergence
issue, but it kept coming back and bite me.
Coming back to this test problem, with the attached 1p
project, I have the following issue.
Standard test: worked.
Increase grid size to 100x100, not converging. It worked
after I, increase # iteration to 1000, reduce convergence
criterion to 10e-6.
Increase grid size to 1000x1000, not converging. I
changed the linear solver from Dumux::BoxCGILU0Solver to
Dumux::BoxCGSSORSolver, and PreconditionerRelaxation from
1.0 to 3.0 as suggested by Bernd, it is still not
converging...
I attached the project folder.
Do you think this maybe related to the Oracle VBox based
Debian installation?
Thanks.
-Shawn
From: Bernd Flemisch <[email protected]>
To: DuMuX User Forum <[email protected]>
Sent: Tuesday, March 27, 2012 4:01 AM
Subject: Re: [DuMuX] Permeability heterogeneity and grid
resolution
Hey Shawn,
with the attached input file, it works for 1000x1000 and
four orders difference. I increased the maximum number of
iterations to 1000 and the residual reduction to 1e-6.
Kind regards
Bernd
On Mon, 26 Mar 2012 11:44:21 -0700 (PDT)
Shawn Zhang <[email protected]> wrote:
Well, I celebrated too fast.
My goal is to determine, in a system of two material
with different perm, when one material can be treated as
having negligible impact on pressure drop.
The two parameters influencing this are,
1. Permeability difference between two materials.
2. Grid resolution.
I use the 1p with lens test problem, and increasing the
perm of the lens material.
At 100x100 resolution, I derive the attached plot
(pressure plot along y=0.5 line), which is saying that
when the permeability difference is greater than 3 order
of magnitude, the material with high permeability can be
seen as open channel flow comparing to the low permeable
phase, and the pressure drop is neglegible. Moreover,
further increase of the perm difference will have a
neglegible effect.
At 10x10 resolution, we start seeing this when the perm
difference is 2 order of magnitude.
When I increase the resolution to 1000x1000, with the
permeability difference 4 order of magnitude, the solver
does not converge again.
Is this the expected behavior, as I am trying to solve
large discontinuity caused by the big perm difference?
-Shawn
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
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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
___________________________________________________________
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
___________________________________________________________
___________________________________________________________
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
___________________________________________________________
// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*****************************************************************************
* Copyright (C) 2010 by Bernd Flemisch *
* Institute for Modelling Hydraulic and Environmental Systems *
* University of Stuttgart, Germany *
* email: <givenname>.<name>@iws.uni-stuttgart.de *
* *
* This program is free software: you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation, either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
*****************************************************************************/
/*!
* \file
*
* \brief The spatial parameters class for the test problem using the
* 1p box model
*/
#ifndef DUMUX_1P_TEST_SPATIALPARAMETERS_HH
#define DUMUX_1P_TEST_SPATIALPARAMETERS_HH
#include <dumux/material/spatialparameters/boxspatialparameters1p.hh>
namespace Dumux
{
/*!
* \ingroup OnePBoxModel
* \ingroup BoxTestProblems
*
* \brief The spatial parameters class for the test problem using the
* 1p box model
*/
template<class TypeTag>
class OnePTestSpatialParameters : public BoxSpatialParametersOneP<TypeTag>
{
typedef BoxSpatialParametersOneP<TypeTag> ParentType;
typedef typename GET_PROP_TYPE(TypeTag, Scalar) Scalar;
typedef typename GET_PROP_TYPE(TypeTag, GridView) GridView;
typedef typename GET_PROP_TYPE(TypeTag, FVElementGeometry) FVElementGeometry;
enum {
dim=GridView::dimension,
dimWorld=GridView::dimensionworld
};
typedef Dune::FieldVector<Scalar,dimWorld> GlobalPosition;
typedef typename GridView::template Codim<0>::Entity Element;
public:
OnePTestSpatialParameters(const GridView& gridView)
: ParentType(gridView)
{
try
{
lensLowerLeft_[0] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensLowerLeftX);
if (dim > 1)
lensLowerLeft_[1] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensLowerLeftY);
if (dim > 2)
lensLowerLeft_[2] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensLowerLeftZ);
lensUpperRight_[0] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensUpperRightX);
if (dim > 1)
lensUpperRight_[1] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensUpperRightY);
if (dim > 2)
lensUpperRight_[2] = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.lensUpperRightZ);
permeability_ = GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.permeability);
permeabilityLens_=GET_RUNTIME_PARAM(TypeTag, Scalar, SpatialParameters.permeabilityLens);
}
catch (Dumux::ParameterException &e) {
std::cerr << e << ". Abort!\n";
exit(1) ;
}
catch (...) {
std::cerr << "Unknown exception thrown!\n";
exit(1);
}
}
/*!
* \brief Return the intrinsic permeability for the current sub-control volume.
*
* \param element The current finite element
* \param fvElemGeom The current finite volume geometry of the element
* \param scvIdx The index sub-control volume face where the
* intrinsic velocity ought to be calculated.
*/
Scalar intrinsicPermeability(const Element &element,
const FVElementGeometry &fvElemGeom,
int scvIdx) const
{
const GlobalPosition &globalPos = fvElemGeom.subContVol[scvIdx].global;
if (isInLens_(globalPos))
return permeabilityLens_;
else
return permeability_;
}
/*! \brief Define the porosity.
*
* \param element The finite element
* \param fvElemGeom The finite volume geometry
* \param scvIdx The local index of the sub-control volume where
*/
Scalar porosity(const Element &element,
const FVElementGeometry &fvElemGeom,
int scvIdx) const
{ return 0.4; }
private:
bool isInLens_(const GlobalPosition &pos) const
{
for (int i = 0; i < dim; ++i) {
if (pos[i] < lensLowerLeft_[i] || pos[i] > lensUpperRight_[i])
return false;
}
return true;
}
GlobalPosition lensLowerLeft_;
GlobalPosition lensUpperRight_;
Scalar permeability_, permeabilityLens_;
};
} // end namespace
#endif
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