CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

cyclic boundaries

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 12, 2009, 07:56
Default cyclic boundaries
  #1
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
Hello,

i have little understanding problem with cyclic boundaries. I want to cut a cylinder into 8 pieces. Now i have to define the boundaries in the blockMeshDich file. I think the liner is a wall, the piston is a wall too and the cylinderhead as well. But what boundary conditions needs the "fictive" left an right wall ? Anybody understand what i mean ? If not i can attach a draft
dipling is offline   Reply With Quote

Old   August 12, 2009, 11:18
Default
  #2
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
The problem ist that layerAR doenst work with cyclic boundaries. I testet 4 cases an everytime it crashes until layerAR wants to delete a layer.
dipling is offline   Reply With Quote

Old   August 13, 2009, 05:55
Default
  #3
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
Ok, either i am annoying everybody with my "dummy" problem or there is really nobody who can help me or there is nobody who can imagine. I attached a simplified draft now.

As u can see I defined the two walls as "cyclic", i think this is pretty standard to use. Stupidly layerAR doenst want to work with these conditons. If i define these two surfaces as a "patch" all is done fine. But i think this would be a problem for solving combustion problems.

Anybody an idea ? Would be very nice
Attached Images
File Type: jpeg piece.jpeg (15.4 KB, 43 views)
dipling is offline   Reply With Quote

Old   August 14, 2009, 05:03
Default
  #4
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
I found out it is a problem in cyclicPolyPatch.C:1253 . In this loop pFaces[i] achieve numbers which cause a segmentation fault. I think it is a bug. I looked in openfoam-1.6 nothing changed at this point. Maybe interesting for jasak ?
dipling is offline   Reply With Quote

Old   August 17, 2009, 10:17
Default
  #5
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
New informations:

The label list needs an update before the loop starts.

Code:
if (!matchedAll)
    {
        label baffleI = 0;
      forAll(*this, faceI)
        {
            const face& f = pp.localFaces()[faceI]; 
        //hole faces
            const labelList& pFaces = pp.pointFaces()[f[0]];
 
        Info << "list size= " << size() << endl; // Debug
        //size_(size);
        //return mesh_.nFaces();
        label matchedFaceI = -1;
        forAll(pFaces, i)
            {
 
                label otherFaceI = pFaces[i];
        //Debug
        Info << " pFaces[i] = " << pFaces[i] << " i=" << i << " and faceI= " 
        << faceI << " and otherFaceI= " 
        << otherFaceI  <<  endl;
        // Debug
            if (otherFaceI > faceI)
                {
                    const face& otherF = pp.localFaces()[otherFaceI];
            Info << "otherFaceI = " << otherFaceI;
                    // Note: might pick up two similar oriented faces
                    //       (but that is illegal anyway)
                    if (f == otherF)
                    {
                        matchedFaceI = otherFaceI;
            Info << "matchedFaceI = " <<  matchedFaceI;
                        break;
                    }
                }
            }
 
            if (matchedFaceI != -1)
            {
                half0ToPatch[baffleI] = faceI;
                half1ToPatch[baffleI] = matchedFaceI;
                baffleI++;
            }
        }

size() is the old number of the cylic faces at this point but for a correct loop he needs the the actual label size because after layerAR faces are removed an renumbered! UListI.H gets it with size_ but i didn't find a way to include this actually.
dipling is offline   Reply With Quote

Old   August 19, 2009, 11:29
Default
  #6
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
Nobody an idea how to read lists ?
Quote:
const labelList& meshPoints = patch().meshPoints();
I want to look which parameters instead of "meshPoints()" exists.

e.g.

patch().facePoints(); (or something like this)

This would be a great help to debug this (i think simple) problem. But it's hard if u didn't write the code.
dipling is offline   Reply With Quote

Old   January 11, 2011, 04:23
Default
  #7
New Member
 
georg's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 17
Rep Power: 17
georg is on a distinguished road
Hi dipling,

it has been awhile. But did you had success? I am running into the same problem as you now. Any hint would be helpful!

Best regards,
Georg
georg is offline   Reply With Quote

Old   January 11, 2011, 05:30
Default
  #8
Member
 
Join Date: Jun 2009
Posts: 36
Rep Power: 16
dipling is on a distinguished road
You have to debug/patch cyclicpolypatch class. I think there was something weird with a loop, but it was easy to solve. And there was another problem with this class, but i can't remember. I stopped this procedure because there were several problems after fixing those bugs. It theoretically worked but the mass was not constant, so finally I waste too much time for one little step. But I stored those fixes (somewhere).
dipling is offline   Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with cyclic boundaries in Openfoam 1.5 fs82 OpenFOAM 36 January 7, 2015 00:31
cyclic boundaries Zealouk Siemens 0 September 17, 2008 11:28
error in cyclic boundaries match Steve Siemens 2 March 4, 2008 04:32
cyclic boundaries gosia stein Siemens 5 June 13, 2007 07:39
Cyclic Boundaries -> Match Option -> Arbitrary Derek Siemens 1 August 4, 2004 22:06


All times are GMT -4. The time now is 21:06.