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January 12, 2016, 16:23 |
cyclicACMI + cyclic
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#1 |
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Yosmcer Mocktai
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I would like to model a moving mesh quite similar to this one:
cyclicACMI allows to couple patches that partially overlap with one another.
Applying cyclicACMI allows to have the correct sliding of the two blocks. It also allows the coupling between the parts of the block that are touching each other. The flowing picture is done with walls set for blue and red marked border. Here the left block is moving up:
Is there a possibility to solve this kind of problem with OpenFOAM (so no foam-extend unfortunately)? Last edited by Yosmcer; January 13, 2016 at 07:01. Reason: Enhance description and improve formating |
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April 15, 2016, 08:15 |
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#2 |
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Yosmcer Mocktai
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Finally I was allowed to use foam-extend, so had access to overlapGgi which works very well for this kind of problems.
So the problem is solved for my use, but may still be relevant to solve for others. Last edited by Yosmcer; April 15, 2016 at 10:06. |
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April 15, 2016, 09:40 |
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#3 |
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Tobias Holzmann
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Hi,
I was thinking that overlagGGI is similar to cyclicACMI because GGI interface is cyclicAMI ... I am not using foam-extend so often and do not know the libs. But probably a lot of stuff is similar (a bit other programming and other names, due to the history of openfoam). For your cyclic case, the problem is that you do not split the mesh.
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April 15, 2016, 10:10 |
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#4 |
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Yosmcer Mocktai
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April 15, 2016, 11:36 |
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#5 |
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Tobias Holzmann
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You have to duplicate the points on the interface that is moving. In each AMI tutorial it is described. You will build a cellZone+faceZone and then create baffles (stationary + moving). After that the mesh could freely move. The best thing to test this is just using moveDyMFoam.
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April 15, 2016, 11:58 |
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#6 | |
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Yosmcer Mocktai
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Quote:
Code:
vertices ( (0 -0.2 0) (1 0 0) <- 1 (1 1 0) <- 2 (0 0.8 0) (0 -0.2 0.1) (1 0 0.1) <- 5 (1 1 0.1) <- 6 (0 0.8 0.1) (1 0 0) <- same as 1 (3 0 0) (3 1 0) (1 1 0) <- same as 2 (1 0 0.1) <- same as 5 (3 0 0.1) (3 1 0.1) (1 1 0.1) <- same as 6 ); This is why it in deed slide correctly in the case when I don't use cyclic ( Sliding.zip ) But on the case I was interested in (which just tried to add the cyclic functionality to the two patches not touching, Problem.zip ), there is a problem as it seems cyclic is not compatible with this kind of moving meshes. |
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April 15, 2016, 12:00 |
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#7 |
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Tobias Holzmann
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Hi,
I never did something like you tried to do. I do not know if cyclic BC can handle your case. Well at last, the picture with cyclic looked like that the points are still be merged. Maybe I will check it somewhen (: At the moment I am fulll of work. PS: In createBafflesDict, did you try to create the baffles with cyclicACMI and then just change the type in the boudnarys? Maybe createBaffles will handle the two types differently. But anyways, you solved it with foam-extend.
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April 15, 2016, 12:05 |
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#8 | |
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Yosmcer Mocktai
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Quote:
This is still interesting for my personal learning and maybe for some others that may be in a similar need. So no hurry and do priority work before |
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April 15, 2016, 12:21 |
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#9 |
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Tobias Holzmann
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Hi,
I checked your case and maybe the way it goes is here: Code:
ACMI1 { //- Use predefined faceZone to select faces and orientation. type faceZone; zoneName couple1Faces; patches { master { //- Master side patch name ACMI1_couple; type cyclicACMI; matchTolerance 0.0001; neighbourPatch ACMI2_couple; nonOverlapPatch ACMI1_blockage; transform noOrdering; } slave // not used since we're manipulating a boundary patch { //- Slave side patch name ACMI1_couple; type patch; } master2 { //- Master side patch name ACMI1_blockage; type wall; } slave2 // not used since we're manipulating a boundary patch { //- Slave side patch name ACMI1_blockage; type wall; } } } Code:
ACMI1_blockage { type movingWallVelocity; value uniform (0 0 0); }
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April 15, 2016, 12:34 |
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#10 | |
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Yosmcer Mocktai
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Quote:
The file you are looking to is the one I used as reference as the sliding was working correctly there. So my try to use cyclic was something like: Code:
ACMI1 { //- Use predefined faceZone to select faces and orientation. type faceZone; zoneName couple1Faces; patches { master { //- Master side patch name ACMI1_couple; type cyclicACMI; matchTolerance 0.0001; neighbourPatch ACMI2_couple; nonOverlapPatch ACMI1_blockage; transform noOrdering; } slave // not used since we're manipulating a boundary patch { //- Slave side patch name ACMI1_couple; type patch; } master2 { //- Master side patch name ACMI1_blockage; type cyclic; matchTolerance 0.0001; neighbourPatch ACMI2_blockage; transform noOrdering; } slave2 // not used since we're manipulating a boundary patch { //- Slave side patch name ACMI1_blockage; type patch; } } } Code:
ACMI1_blockage { type cyclic; value $internalField; } |
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August 17, 2016, 14:10 |
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#12 | |
Member
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Dear Yosmcer,
Did you finally have any success to apply cyclic for non overlapping faces? Regards Quote:
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August 17, 2016, 14:19 |
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#13 |
Member
Yosmcer Mocktai
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At the end we were allowed to use foam-extend which can do it with the overlapGgi.
Up to what I understood, there is no "easy" solution to do this with the base OpenFOAM. This is of course possible, but would require quite some times (month time scale), whereas I only had few times for this. |
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August 17, 2016, 18:05 |
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#14 |
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Tobias Holzmann
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Finally that is the only possible way at the moment. I made some bug/features report to the Foundation version. The cyclic will not work in my opinion because normally you first make baffles where we copy / dublicate existing face ... If the faces are not close to each other it will not work. Here you would need a new bc like ACMIBlockedCyclic that checks which faces should be mapped together.
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March 12, 2018, 01:23 |
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#15 |
New Member
Harshal Akolekar
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Hi,
Is this working in the base OpenFOAM by any chance now. I am interested in simulating this as well? If not can you please elaborate on the procedure using foam-extend. Regards, |
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March 18, 2018, 10:57 |
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#16 |
Member
Yosmcer Mocktai
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Hi hakolekar,
I have no idea on the changes made in this mater. Foam-extend is a separate code that can be used instead of OpenFoam. It shares some code with OpenFoam, but is a stand-alone solution as far as I could see. The procedure to install is described here: http://openfoamwiki.net/index.php/In...oam-extend-4.0 For how to use, you have some examples in the tutorials folder, such as: https://github.com/Unofficial-Extend...m/axialTurbine Best of luck, |
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March 19, 2018, 20:05 |
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#17 |
New Member
Harshal Akolekar
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Hi Yosmcer,
Thank you for your reply. I have installed the foam-extend version as per the link that you have sent me. I am actually interested in simulating a moving cylinder (linear motion) and that sheds a wake on a turbomachine blade (with cyclic boundaries - something similar to the .gif file at the top of this post). As such the simulation is 2D (obviously I will have one cell in the Z direction in order to facilitate the requirements of OpenFOAM). I will also be using a grid that has been generated using the plot3dtoFOAM command. And am therefore wondering how to incorporate the overlapggi for the same. I would be grateful if you have any tips, simulations or code to look at as a starting point. The moving cylinder tutorial crashes about 2 sec after the simulation has started. Any idea why this is happening? Thank you. Regards, Harshal. |
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April 1, 2018, 08:03 |
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#18 | ||
Member
Yosmcer Mocktai
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Quote:
Quote:
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February 12, 2019, 20:12 |
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#19 |
New Member
Harshal Akolekar
Join Date: Aug 2016
Location: Melbourne
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Hi,
Thanks for the animation. Can you direct me with the usage of boundary conditions. I am using totalPresssure, totalTemperature and pressureDirectedInletVelocity at the inlet. Also do I have to account for the relative motion while prescribing BCs. A guide to BC prescription would help a lot. Thank you. Regards, Harshal |
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