periodic boundaries
I want to define two rotational periodic boundaries (the angle between them is 180°). They are identically (equal number of faces, equal geometry).
/grid/modify-zones> make-periodic Periodic zone [()] 5 Shadow zone [()] 7 Rotational periodic? (if no, translational) [yes] yes Create periodic zones? [yes] yes zone 5: matched 13596 out of 15234 faces. zone 7: matched 13596 out of 15234 faces. Error: Failed to make zones periodic. Error Object: #f Can someone help me ?? |
Re: periodic boundaries
can u specify the details of the geometry, then we can discuss about the problem - thanks!
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I'm now face the same problem
could any one pls, tell me how to fix this problem |
Re: periodic boundaries
Has anyone determined a solution to this problem in Fluent? I also am working on simulations that require rotational periodicy. Occasionally I am able to create the periodic zones, but sometimes I receive the errors: "Error: Failed to make zones periodic. Error Object: #f"
I believe that I am not doing anything different when I create the periodic zone successfully. I am always ensuring that the rotational axis is aligned with the z-axis of the geometry and I am using match control in meshing for the two faces of the periodic zone. Any ideas of what may casue this? |
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Type in Fluent command Window >Mesh >mp if doesn't work try to type the following and change number >Mesh >Mz >Mt "change value (limit is 0.5)" |
i faced the same problem. maybe u shoud make periodic in your meshing software ,then export the grid,at last import into FLUENT、、、、、、、which meshing software you are useing??ICEM CFD can do it.
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*I know I am late but, you must have the axis of rotation in the global z-direction for rotational periodicity. It may also be true that translational periodicity must be orthogonal across z as well.
Use /mesh/rotate in the interpreter and set your point of origin and axis of mesh rotation so that the global z-axis is parallel with the axis of periodicity use /mesh/mz/make-periodic in the interpreter and move on as usual. You can also invoke periodicity in your meshing software (* Z-axis and axis of periodicity must be parallel) and Fluent should take care of it from there. If there is a way to make the stored axis something other than (0 0 1) or any other vector, none of the above would matter. |
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The default tolerance can be problematic in small meshes just use the text command grid/modify-zone/mt and specify smaller tol's untill all nodes are matched up and then you're good to go I had to reduce from 0.1 to 1e-6 |
I was facing the same problem and I solved it by changing the rotation axis on the "cell zone condition" tab. My geometry was rotationally periodic along x axis but standard fluent settings use the z axis as the rotation axis.
I hope this helps! Cheers, Rob |
This is problem of mesh, if you not mesh same cell size and division on periodic boundaries, Fluent through this error, If you want to avoid
1.Remesh,with match control. 2.If it irregular geometry then use periodic interface in fluent ( interface option defining boundaries as interface ) |
wdxgd
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I faced the same problem and just swapped the shadow region with periodic region and the periodic zone was successfully created.
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Hi everyone,
in my case I have resolved the problem making higher the tolerance (from 0.05 to 0.1). I think the problem comes from the CAD geometry. If the periodic domains from the CAD software are not clean (that means, there are overlapping between the periodic elements), fluents doesn´t like it and appears the error. If you increase the tolerance value (grid/modify-zone/mt), fluent doesn´t take into account this ovelapping. Bye luiscssz |
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warnning : your interfaces may adversely affected by the periodic creation.. what should I do? Thanks |
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This is my impeller and I want to make periodicity in fluent..Thanks
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How to do that in ICEM CFD?
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thanks in advance |
Is your flow direction axis defined correctly in your "Cell Zone Conditions". If your direction axis is wrong, fluent wont be able to create a periodic boundary condition.
Hint: If your mesh is periodic, fluent should detect it on it's own. |
In ANSYS R 18.2 for translational cyclic boundary condition I used
the command line of Fluent to create it, following the description of https://www.researchgate.net/post/Ho...actually_means /mesh/modify-zones> make-periodic Periodic zone [()] 25 Shadow zone [()] 26 Rotational periodic? (if no, translational) [yes] no Create periodic zones? [yes] yes Auto detect translation vector? [yes] no x-direction (m) [0] 0 y-direction (m) [0] -0.0273 z-direction (m) [0] 0 translation deltas: 0.000000 -0.027300 0.000000 zone 26 deleted created periodic zones. Hint: Fluent tried to compute the delta in y-direction itself but calculated a value of -0.02731. The creation of the periodic zones failed during auto detect. Hence, I just entered the correct offset myself (Auto detect translation vector? [yes] no) and it worked. |
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