CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Problem using AMI

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree28Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   May 8, 2012, 07:23
Default
  #81
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Hello Everyone,
Have been stuck with AMI implementation for some time now and require some help guys.

Review of Problem: trying to solve rotating square in regular fluid domain.
Case file here: http://db.tt/59ubLm1j

Error: See after few iteration the delta T becomes irrelevant ( controlDict) and solver selects depending on courent number i suppose do not know why?

Note 1: "NAN" is last value that solver gets and stops.
GAMG: Solving for p, Initial residual = nan, Final residual = nan, No Iterations 50
time step continuity errors : sum local = nan, global = nan, cumulative = -nan
PIMPLE: iteration 2
smoothSolver: Solving for Ux, Initial residual = nan, Final residual = nan, No Iterations 1000
smoothSolver: Solving for Uz, Initial residual = nan, Final residual = nan, No Iterations 1000
--> FOAM FATAL IO ERROR:
wrong token type - expected Scalar, found on line 3 the word 'nan'
file: /home/chandra/OpenFOAM/chandra-2.1.x/run/roCube/system/data::solverPerformance::U at line 3.
From function operator>>(Istream&, Scalar&)
in file lnInclude/Scalar.C at line 91.
FOAM exiting

Note 2: If you see the AMI line i.e this line . We see 0 source face and 0 target faces. Is it right or wrong ? Really no idea.
I thought some faces should be there to transfer values.
.AMI: Creating addressing and weights between 0 source faces and 0 target faces


Any idea people, ?????

Commands i executed.
1.blockMeah
2 snappyHexMesh
3 mergeMeshes rotor/ stator/ (above 2 steps were repeated separately for rotar and stator.)
4 topoSets
5 ChangeDirectory
6 pimpleDyFoam
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better

Last edited by kid; May 8, 2012 at 08:28. Reason: few more questios
kid is offline   Reply With Quote

Old   May 8, 2012, 22:16
Default
  #82
Senior Member
 
linnemann's Avatar
 
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 451
Rep Power: 15
linnemann will become famous soon enough
Look in your boundary file

Code:
    AMI1_patch0
    {
        type            cyclicAMI;
        nFaces          0;
        startFace       23605;
        matchTolerance  0.0001;
        neighbourPatch  AMI2_patch0;
        transform       noOrdering;
    }
    AMI2_patch0
    {
        type            cyclicAMI;
        nFaces          0;
        startFace       23605;
        matchTolerance  0.0001;
        neighbourPatch  AMI1_patch0;
        transform       noOrdering;
    }
both AMIs has 0 faces

also your changeDictionary

Code:
dictionaryReplacement
{
    boundary
    {
        AMI1_patch0
        {
            type            cyclicAMI;
            nFaces          0;
            startFace       24985;
            neighbourPatch  AMI2_patch0;
            transform       noOrdering;
            surface         
            {
            }
        }
        AMI2_patch0
        {
            type            cyclicAMI;
            nFaces          0;
            startFace       24985;
            neighbourPatch  AMI1_patch0;
            transform       noOrdering;
            surface         
            {
            }
        }
    }
}
here you set both to have the same startface and 0 nFaces, if I where you I would not use changeDictionary as it obviously does not do what you think it does. Change the files manually.
__________________
Linnemann

PS. I do not do personal support, so please post in the forums.
linnemann is offline   Reply With Quote

Old   May 9, 2012, 01:00
Default
  #83
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Hi linnemann,
Thank you for reply.
Same case after modification you suggested is here:
http://dl.dropbox.com/u/70019943/roCube2.tar.gz

Yes you are right i do not need changeDict file (silly on my part even after understanding i tried to use it as it made Solver to run ). Now when i change manually :
splitMeshRegions -makeCellZones -overwrite
This gives error as under.
Now the good part is this "weights between 1380 source faces and 1504 target".
Is there something i am terribly missing????

HTML Code:
Reading volScalarField cellToRegion
Reading volScalarField p
AMI: Creating addressing and weights between 1380 source faces and 1504 target faces
--> FOAM FATAL ERROR: 
Unable to set source and target faces
    From function void Foam::cyclicAMIPolyPatch::setNextFaces(label&, label&, const primitivePatch&, const primitivePatch&, const boolList&, labelList&, const DynamicList<label>&) const
    in file lnInclude/AMIInterpolation.C at line 878.
FOAM aborting
#0  Foam::error::printStack(Foam::Ostream&) in "/home/chandra/OpenFOAM/OpenFOAM-2.1.x/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better
kid is offline   Reply With Quote

Old   May 9, 2012, 02:53
Default
  #84
Senior Member
 
linnemann's Avatar
 
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 451
Rep Power: 15
linnemann will become famous soon enough
If you had spent just 2min on viewing the case in paraview and enabling the two AMIs like in the screenshot you will see why you have an error.
Attached Images
File Type: jpg ScreenShot088.jpg (36.4 KB, 468 views)
__________________
Linnemann

PS. I do not do personal support, so please post in the forums.
linnemann is offline   Reply With Quote

Old   May 9, 2012, 03:04
Default
  #85
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Sir ,
Is it because of tooth edges on AMI1_patch0.
Really sorry if this question is too trivial.
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better

Last edited by kid; May 9, 2012 at 03:09. Reason: spell
kid is offline   Reply With Quote

Old   May 9, 2012, 03:38
Default
  #86
Senior Member
 
linnemann's Avatar
 
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 451
Rep Power: 15
linnemann will become famous soon enough
also that, but also because one of the sides of the AMI contains the top and bottom faces.

The ami should be 1:1 geometry wise, not mesh, but the extend and size must be the same.
__________________
Linnemann

PS. I do not do personal support, so please post in the forums.
linnemann is offline   Reply With Quote

Old   May 9, 2012, 03:46
Default
  #87
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Sir,
" because one of the sides of the AMI contains the top and bottom faces"
This is not clearly understood by me. Could you elaborate?

Also geometry should be 1:1 . What this means ?
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better
kid is offline   Reply With Quote

Old   May 9, 2012, 04:00
Default
  #88
Senior Member
 
linnemann's Avatar
 
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 451
Rep Power: 15
linnemann will become famous soon enough
The regions on each side of the AMI Connections are not allowed to be of different sizes and have non-overlap regions.
__________________
Linnemann

PS. I do not do personal support, so please post in the forums.
linnemann is offline   Reply With Quote

Old   May 9, 2012, 04:15
Default
  #89
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Well AMI1_patch0 is a cylindrical mesh with square. ( this will have upper and lower faces)
And AMI2_patch0 is the other one that is a hollow cylinder with no top and bottom surface.

If not his way what should be the logic to implement both AMI Sir?

Or any other pointer?

Or If we forget all doubts above . What should be the expected look in paraview on selecting both AMI patchs?
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better
kid is offline   Reply With Quote

Old   May 9, 2012, 07:05
Default
  #90
Senior Member
 
Attesz's Avatar
 
Attesz
Join Date: Mar 2009
Posts: 355
Rep Power: 8
Attesz is an unknown quantity at this point
Hi Foamers,

have you tried AMI rotating things using unstructured tetrahedral mesh? In my case I have to use it due to the complexity of my geometry, but I have convergence problems (blowing up pressure fields).

Best,
A
__________________
CFD= Cleverly Formatted Data
Attesz is offline   Reply With Quote

Old   May 9, 2012, 07:50
Default
  #91
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Hello Attesz,
What tool you used for generating unstructured Mesh? Any OpenSource tool??
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better
kid is offline   Reply With Quote

Old   May 9, 2012, 07:51
Default
  #92
Senior Member
 
Attesz's Avatar
 
Attesz
Join Date: Mar 2009
Posts: 355
Rep Power: 8
Attesz is an unknown quantity at this point
Quote:
Originally Posted by kid View Post
Hello Attesz,
What tool you used for generating unstructured Mesh? Any OpenSource tool??

Hi, no, i'm using ICEM CFD.
__________________
CFD= Cleverly Formatted Data
Attesz is offline   Reply With Quote

Old   May 9, 2012, 22:02
Default
  #93
Senior Member
 
linnemann's Avatar
 
Niels Nielsen
Join Date: Mar 2009
Location: NJ - Denmark
Posts: 451
Rep Power: 15
linnemann will become famous soon enough
In your case both the AMI's have to be a hollow cylinder with no top and bottom
__________________
Linnemann

PS. I do not do personal support, so please post in the forums.
linnemann is offline   Reply With Quote

Old   May 12, 2012, 00:57
Default
  #94
Member
 
Jason Eason
Join Date: Jan 2010
Location: Portage, Michigan
Posts: 44
Rep Power: 7
JulytoNovember is on a distinguished road
Linneman, what would you suggest to do with the top and bottom? Inlets and outlets or would you change the nfaces to 0? Or would you suggest something else?
__________________
Debian Squeeze - OpenFOAM-2.1.x, Paraview-3.12.0
JulytoNovember is offline   Reply With Quote

Old   May 23, 2012, 14:57
Default Bugreport, please contribute
  #95
Senior Member
 
Attesz's Avatar
 
Attesz
Join Date: Mar 2009
Posts: 355
Rep Power: 8
Attesz is an unknown quantity at this point
Dear all,

I've just created a bugreport on OpenFOAM Mantis (http://www.openfoam.org/bugs/) issue 0000539 in this topic (AMI weight goes down to 0).

Please contribute with your observations to solve this bug asap.

Best regards,
Attesz


Quote:
Originally Posted by vinz View Post
Dear all,

It's been a while since I did not post on the forum, but I am still following with attention the new developments.
I tried to use the AMI feature with pimpleDymFoam on the tutorial propeller. It works perfectly and look very promising.
So I decided I would try it on one of my own model, and see what I get. Unfortunately, it always break up at some point whatever I use for the max courant number, or the relaxation factors, or many different things I tried.

I just notice that the last time step writes the following lines:

Code:
solidBodyMotionFunctions::rotatingMotion::transformation(): Time = 0.00123617 transformation: ((0 0 0) (0.981207 (0 0 0.192959)))
AMI: Creating addressing and weights between 23366 source faces and 23366 target faces
AMI: Patch source weights min/max/average = 0.000261522, 1.75988, 1.00123
AMI: Patch target weights min/max/average = 0, 1.3569, 1.00084
PIMPLE: iteration 1
I guess now the problem is coming from the "0" we can see just above. Am I right? What does it exactly means? and how can I solve this problem?

Thanks in advance for your advice.
__________________
CFD= Cleverly Formatted Data
Attesz is offline   Reply With Quote

Old   May 24, 2012, 00:36
Default
  #96
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Hi Attesz,
Its good that you have reported this issue.

Also in my case it is lack of my understanding of AMI that is creating problem, i suppose.
Attesz likes this.
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better
kid is offline   Reply With Quote

Old   May 24, 2012, 02:19
Default
  #97
Senior Member
 
stephane sanchi
Join Date: Mar 2009
Posts: 300
Rep Power: 9
openfoam_user is on a distinguished road
Hi Attesz,

Now for me it works but only when I generate the grid with ICEMCFD Hexa.

When I generate the mesh with snappyHexMesh (like propeller tutorial) it crashes. Same error as you. Strange because residuals and convergence history is smooth until the crash.

I hope that the AMI robustness will be improved.

Regards,
Stephane
Attesz likes this.
openfoam_user is offline   Reply With Quote

Old   May 24, 2012, 06:01
Default
  #98
New Member
 
Alexander Tagirov
Join Date: Feb 2011
Location: Moscow, Russia
Posts: 7
Rep Power: 6
Randomizer is on a distinguished road
Hi Attesz,
I've had a lot of trouble with the same issue you posted. You see, when AMI gets zero weights, that means that during the interpolation to one of the faces on one AMI patch it couldn't find any faces on second AMI patch that has a projection to this face. The reason for this could be a bug in search/interpolation algorithm, or not a very good mesh. The AMI patches should be as much identical as possible (I mean the mesh, because geometry should be totally the same) , especially if they are cylindrical.
Randomizer is offline   Reply With Quote

Old   May 24, 2012, 06:08
Default
  #99
kid
Senior Member
 
cfdkid
Join Date: Mar 2009
Posts: 133
Rep Power: 8
kid is on a distinguished road
Hi All,
SUccess after almost 2 months in using AMI.
Though i used "SALOME" mesh imported in OpenFOAM-21x.
Also results are not good!!

But the weights are getting transfered though. Something like this.
AMI: Patch source weights min/max/average = 0.965339, 1.1551, 1.00005
AMI: Patch target weights min/max/average = 0.996065, 1.02292, 1.00278

Next step would be improving mesh again. Thanks everyone specially "linnemann" stephane and lovecraft. And you also guys.
__________________
________________________________________
Regards,
CFDkid

It never gets easier You just get Better

Last edited by kid; May 24, 2012 at 06:32.
kid is offline   Reply With Quote

Old   May 24, 2012, 07:52
Default
  #100
Senior Member
 
Attesz's Avatar
 
Attesz
Join Date: Mar 2009
Posts: 355
Rep Power: 8
Attesz is an unknown quantity at this point
Ok but how did you manage to make it work?

Quote:
Originally Posted by kid View Post
Hi All,
SUccess after almost 2 months in using AMI.
Though i used "SALOME" mesh imported in OpenFOAM-21x.
Also results are not good!!

But the weights are getting transfered though. Something like this.
AMI: Patch source weights min/max/average = 0.965339, 1.1551, 1.00005
AMI: Patch target weights min/max/average = 0.996065, 1.02292, 1.00278

Next step would be improving mesh again. Thanks everyone specially "linnemann" stephane and lovecraft. And you also guys.
__________________
CFD= Cleverly Formatted Data
Attesz is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
UDF compiling problem Wouter Fluent UDF and Scheme Programming 6 June 6, 2012 04:43
Gambit - meshing over airfoil wrapping (?) problem JFDC FLUENT 1 July 11, 2011 05:59
natural convection problem for a CHT problem Se-Hee CFX 2 June 10, 2007 06:29
Adiabatic and Rotating wall (Convection problem) ParodDav CFX 5 April 29, 2007 19:13
Is this problem well posed? Thomas P. Abraham Main CFD Forum 5 September 8, 1999 14:52


All times are GMT -4. The time now is 04:17.