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-   -   Non-conformal mesh interface and Pointwise (https://www.cfd-online.com/Forums/pointwise/189073-non-conformal-mesh-interface-pointwise.html)

AhmedSaad June 12, 2017 12:44

Non-conformal mesh interface and Pointwise
 
Is there a way to create a non-conformal mesh interface in pointwise?
I am trying to run a transient simulation for my horizontal axis wind turbine model using sliding mesh method but it seems that fluent solver has some issues with the conformal interface between the rotating cylinder and the enclosure resulting in creating a negative volume cells that cause the solver to fail.
I tried to double and separate the interface domains or connectors but I failed even if I separate cylinder and enclosure in two layers.
Any suggestions!

rmatus June 12, 2017 17:05

As far as I know, Fluent does not care if the meshes on a sliding interface are conformal or not, but I'll leave that to a Fluent expert.

To answer your Pointwise question, you do not need to create two domains at the sliding interface. Instead, go to the CAE, Set BCs menu, and change both sides of the sliding interface domains to type interface. When you export the Fluent CAE file, they will automatically be split into separate zones.

If you truly want to make a non-conformal interface, you will have to make some change to the grid on one side of the interface so the two sides are not identical. One way to do that is to change the number of grid points on one side. Just copy the interface domain, paste, and then redimension while still on the paste panel before saving.

AhmedSaad June 12, 2017 17:26

Quote:

Originally Posted by rmatus (Post 652887)
As far as I know, Fluent does not care if the meshes on a sliding interface are conformal or not, but I'll leave that to a Fluent expert.

To answer your Pointwise question, you do not need to create two domains at the sliding interface. Instead, go to the CAE, Set BCs menu, and change both sides of the sliding interface domains to type interface. When you export the Fluent CAE file, they will automatically be split into separate zones.

If you truly want to make a non-conformal interface, you will have to make some change to the grid on one side of the interface so the two sides are not identical. One way to do that is to change the number of grid points on one side. Just copy the interface domain, paste, and then redimension while still on the paste panel before saving.

Thanks for your reply!
I 90% believe that the cause of the negative volume message I receive when running sliding mesh method is the contact interface. I am sure of that because I had the same problem last year before I start working on pointwise. I was using Ansys meshing and when redefining the interface as a non-conformal, I solved the problem.

I tried your suggestion (copy, past and redimension while still on the paste panel) but still doesn't work. The interface domains I just copied doesn't appear in the domain list. However, in the message panel, it seems the domains have successfully been copied.

rmatus June 12, 2017 17:37

Did the total number of domains and connectors change after you copied and pasted the domain? Just to be clear, when you redimension the copied domain you have to give it a different number of grid points than the original domain.

Pointiwse does not allow identical domains to exit in the same location, so it will merge the two domains back together if they are identical.

AhmedSaad June 12, 2017 17:42

It works now.
Sorry, I just forgot to press the dimension button before pressing oK.

Thanks for your time!

rmatus June 12, 2017 17:44

Glad to hear it worked.

kemin May 18, 2018 10:28

non-conformal interface
 
In Fluent, non-conformal interface is need for sliding mesh.
you can mesh the inner rotating domain and outer stationary domain respectively ( 1 physical surface, but two domains) in Pointwise.


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