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-   -   Cyclic GGi Vs cyclic patch (http://www.cfd-online.com/Forums/openfoam/87179-cyclic-ggi-vs-cyclic-patch.html)

kurne April 13, 2011 06:00

Cyclic GGi Vs cyclic patch
 
Dear All

Will anybody explain what is the difference between the Cyclic GGi Vs cyclic patch.I am asking this because i have run my case with cyclic patch in OpenFOAM 1.7.1 and the same case is not running in OpenFOAM 1.5-Dev and giving error.But i resolve this problem in OpenFOAM 1.5-Dev by changing the patch conditions i.e.cyclic to fixed value.

Please Help.

Thanks In Advance.

maddalena April 13, 2011 07:35

Quote:

Originally Posted by kurne (Post 303408)
Dear All

Will anybody explain what is the difference between the Cyclic GGi Vs cyclic patch.I am asking this because i have run my case with cyclic patch in OpenFOAM 1.7.1 and the same case is not running in OpenFOAM 1.5-Dev and giving error.But i resolve this problem in OpenFOAM 1.5-Dev by changing the patch conditions i.e.cyclic to fixed value.

Please Help.

Thanks In Advance.

cyclic requires the two patches to be exactly the same. CyclicGGI does not; however, as far as I know, cyclicGGI is available on -ext version only.

mad

kurne April 15, 2011 00:49

Dear maddalena

Yeah thats right maddalena cyclic required two patches and cyclicGGI is available with extension version but i want to know the difference between two.

Well, if u and anyone know how to apply cyclicGGI then please let me know because i an stuck up with the cyclicGGI conditions.

Lastly thanks a lot for replying.

maddalena April 15, 2011 03:07

Quote:

Originally Posted by kurne (Post 303710)
i want to know the difference between two.

There is no difference on the results between the two. However:
Quote:

Originally Posted by maddalena (Post 303420)
cyclic requires the two patches to be exactly the same. CyclicGGI does not.

In order to create a cyclic, you use createPatchDict, while to create a cyclicGGI this is not required and you change by hand the constant/polyMesh/boundary file.

mad

kurne April 15, 2011 03:35

Dear maddalena
With the guidance of you only i have created the cyclic patch and will you please tell me changes should i made for cyclicggi in constant/polyMesh/boundary file.

As i am not getting any perfect data on it otherwise i have tried for it.Please give me the directions.


Thanks in advance.

gascortado August 4, 2011 14:04

Hi.

I used to work with OF16 and used to used cyclic BC with the createPatch utility. Now I switched to OF16ext and I realized that the set up of cyclic BC are not longer the same as it used to. Now, I read thru the wiki http://openfoamwiki.net/index.php/Si...setup_the_case

in order to set up my case. Everything is fine, but my only question is this: what do I have to specify as "zone"?

My case is a simple rectangular domain where the left and right boundaries need to be periodic.

I will really appreciate any help. Thanks

maddalena August 5, 2011 03:05

Hello,
Quote:

Originally Posted by gascortado (Post 318913)
my only question is this: what do I have to specify as "zone"?

In your case, I think that the zone definition is used for decomposition only. As far as you run on a single processor you do not need it.
In any case, a zone is a group of points/faces/cells in your mesh that have a single specific propriety. It can be created in a wide number of way. In your case, I think you need a faceZone, which can be generated starting from the patch these faces belong to. How to create it? Type setSet on your terminal window. ;)

Hope to be clear

mad

aqua February 2, 2012 12:36

Hello, mad,
May I ask you a question please?
for rotor--stater case, after regionCellsets, there are two regions created, named:
cellRegion0.gz cellRegion1.gz
How could I know which one is the rotor?
Thank you so much!
Aqua


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