2D adaptive Mesh Refinement
Hello Foamers,
i am new here. i am not sure if it is right posting my problem in this forum... i hope it is ok. I did create an adaptive mesh using dynamicRefineFvMesh. I adapted the hexRef8 class for splitting cells in 2D. Now i started my solver and the cell refinement runs good (the mesh check is OK) and now the big BUT it comes ... Always if the mesh changes the calculations will be solved in 3D, i.e. the vector of velocity is directed in the 3.dimension. And now comes sth weird. If i stop the calculation and then i re-start it from the last timestep then the calculation is correctly calculated in 2D. What is the problem, i have absolutely no idea. many thanks |
:) dear buddy, maybe you want to share your code and one test case here, maybe we can help you to solve the problem :)
|
Hey,
As far as I know, the cut engine hexRef8 is only capable to cut cell into 8 subcells, which means it is 3 dimensions. I have seen a paper talking about cut cells in to 2 subcells, I think you look it up here: http://publications.lib.chalmers.se/...173/174173.pdf Another question is, what solver are u using? I am now trying to implement AMR into steady solver.But I met some problems. |
I'm also working on a 2D adaptive mesh refinement with a dynamicFvMesh. Does anybody have an idea whether it's good to start modifying the hexRef8 class, keeping its low-level style (which is really complicated) or if one could adapt hexRef8, keep using all its nice features and just plug in simpler mesh modification operations?
I successfully managed to do exactly the refinement I want using multiDirRefinement which gives me the type of meshes I want BUT It still lacks all the other capabilities which are needed for a dynamic mesh (like: field mapping, keeping track of the refinement history, allowing unrefinement etc.) What I'd like to do is: take hexRef8 and rewrite it partially, using the code from multiDirRefinement, thus turning it into a hexRef4 or hexRef2. Does anybody have a good idea how to start? |
Have you seen this thesis? (http://digitalcommons.mtu.edu/cgi/vi...8&context=etds)
Especially Apendix B. It seems like the 2D adaptive mesh refinement we are looking for. |
Hi,
does anyone of you managed to implement the 2D engine for dynamic local mesh refinement? I'm trying to do it according to mentioned paper: [Ahmad Baniabedalruhman] http://digitalcommons.mtu.edu/etds/1005/[/URL] I'm currently struggling with the code from appendix B related to splitting of internal faces. Does anyone know how the variable anchorPointJ should be initialized? It is appearing on the page 173 when author is proposing the algorithm for splitting internal faces. Regards, Jakub. |
Hi Jakub,
I am also currently trying to get the adaptive mesh refinement to run in 2D following the Baniabedalruhman thesis. It seems to me that the modifications are neither complete nor all correct. With some modifications, I was able to compile the new library but my code crashes during the first refinement step. For the anchorPointJ I have added: label anchorPointJ = anchors.otherVertex(anchorPointI); Send me a PM if you are interested in a discussion:) Hannes |
Hi Hannes89,
I am interested in adaptive mesh refinement. I found and fixed some problems, but I still don't understand how to declare: -anchorPointJ -isDivisibleFace -isDivisibleEdge. Did you solve the problems? Could you help me? Regards, Carmelina |
Catelyn,
together with Hannes89, we are trying to implement this solution. You can join us if you want. The more the better :) On monday I will try to give you some hints regarding those variables. Regards, Jakub. |
Hi Catelyn,
the isDivisible variables should be boolean lists, holding a value for every face and edge, that can be declared like this: boolList isDivisibleFace(mesh_.nFaces(),false); boolList isDivisibleEdge(mesh_.nEdges(),false); Regarding the anchorPointJ. I am not so sure about the algorithm implemented in the PhD thesis and can not give you a definitive answer. I am currently trying to rewrite this bit of the code. Hannes |
Hi,
here are my thoughts regarding variables you asked.
When it comes to anchorPointJ, we don't know yet what it should be. Kuba. |
Thank you all,
I realized they were boolean variables but I have a too approximate knowledge in programming. I wrote to Dr. Baniabedalruhman, I'll keep you posted if I receive any answers. Catelyn |
2d amr
Quote:
|
Quote:
Catelyn |
I have study the codes at Appendix B in the thesis of http://digitalcommons.mtu.edu/cgi/vi...8&context=etds. I changed the codes as the thesis suggest, but when I run my 2d heat transfer case, there's error. And I output the debug informaion, I found basically those values are right.
I find the error was occur in the function createInternalFaces ( original in file hexRef8.C for 3D ,but I change this file hexRef4.C for 2D) . The "if (edgeMidPointI==-1)" judgement ,which I think is the key problem, because for 2D problem ,the value of edgeMidPointI of empaty boundary 's edge are not -1, but the value of edgeMidPointI of internal edges are -1, so when loop the interal edge this judgement is right, it will output the wrong message,and stop the programm. So, I look into the function of storeMidPointInfo, I want to do some change, but I do not unstand its theory. I will continue to handle this problem. Is there anyone can give me some help how to sovle this problem? If I successed to run the 2D AMR , I will show the codes! http://www.cfd-online.com/Forums/mem...831-cell0.html http://www.cfd-online.com/Forums/mem...re829-mesh.png http://www.cfd-online.com/Forums/mem...mperature.html http://www.cfd-online.com/Forums/mem...33-output.html http://www.cfd-online.com/Forums/mem...l0details.html |
Hi,
I recently started to work on this problem too. I tried to implement the (in)famous code described in Dr. Baniabedalruhman's thesis in Openfoam 3.2 extend, whose dynamicMesh libraries are very close to the "standard" version. As already reported, the description of the code in the thesis is quite incomplete. After some modification, I reached the same point of XuDongNa: when runiing the solver, the refinement process stops when the first cell is split as the createInternalFaces function sends an error because the edgeMidPointl is not set. Unfortunately, I don't have much time to work on this. Where you able to solve the problem? |
5 Attachment(s)
Dear All
Here is the code and a case following the introduction of the Ahmad thesis, It doesnt run! here is the error it looks like that spilitting the faces and edges are done correctly, however, it has errors when creating the internal faces. Quote:
Attachment 52595 Attachment 52596 Attachment 52597 Attachment 52598 I hope that somebody could share his successful implementation of the 2D AMR. Mahdi |
1 Attachment(s)
Attached, you can find the code I developed.
From my tests, It seems to work well with 2D meshes. Anyway, the refining part of the code can be improved. (the code is developed for foam-extend 3.2, most of it is anyway the same of the standard OpenFOAM version). |
1 Attachment(s)
Here is Luca Cornolti's code adapted for OpenFOAM 4.0. I've made it by line-by-line comparisons:
(original dynamicRefineFvMesh+hexRef8 for foam-extend 3.2) <-> (dynamicRefineFvMesh2D+hexRef2D for foam-extend 3.2) and (original dynamicRefineFvMesh+hexRef8 for foam-extend 3.2) <-> (original dynamicRefineFvMesh+hexRef8 for OpenFOAM 4.0). I understood only about 30% of the code, and ran only very basic tests, so cannot guarantee that everything is correct. But it seems to work OK at least in single-process mode. I also added basic support of axisymmetric 2D ("wedge" boundary condition), but cells that are directly adjacent to the symmetry axis would not refine since they are not parallelepipedal. In OpenFOAM 4.0 code structure is slightly different. Complete installation is as follows (assuming you installed OF4 into '/opt/openfoam4/'): 1. put 'dynamicRefineFvMesh2D' folder into '/opt/openfoam4/src/dynamicFvMesh/' folder; add 'dynamicRefineFvMesh2D/dynamicRefineFvMesh2D.C' line into '/opt/openfoam4/src/dynamicFvMesh/Make/files'; run 'wmake' command from 'opt/openfoam4/src/dynamicFvMesh/'; 2. put 'hexRef2D' folder into 'opt/openfoam4/src/dynamicMesh/polyTopoChange/polyTopoChange/' folder; add 'polyTopoChange/polyTopoChange/hexRef2D/hexRef2D.C' line into '/opt/openfoam4/src/dynamicMesh/Make/files'; run 'wmake' command from 'opt/openfoam4/src/dynamicMesh/'; Enjoy! |
2D+axisy. codes
2D+axisy. dynamic mesh refinement can be found in the link below.
http://faculty.yu.edu.jo/ahmad_a/Lis.../AllItems.aspx |
All times are GMT -4. The time now is 01:44. |