Learning Forum

[Thodorisdm]

Dear, 

I am studying the below case. In the beginning, I have the periodic boundaries assigned as walls and then I select them periodic-->conformal-->translation and assign their distance in x-direction as the translation value. When I run my simulation after some time-steps-around 80 I get the following : 

Error at Node 24: Interface node number mismatch! (112, 116)

Error at Node 35: Interface node number mismatch! (116, 112)

 

I suspect there is something wrong with the periodic assignment but I can't find what could it be. 

Kind regards, 

Thodoris

[Federico Alzamora Previtali]

Depending on how you generated your mesh, the interfaces might not be conformal. Can you try without choosing Conformal?

[Thodorisdm]

Thank you for your reply. However, they are conformal since I made them to have exactly the same nodes.

[Federico Alzamora Previtali]

I would suggest you still try, to help in pinpointing what the issue is. The error message suggests they are not conformal.

[Thodorisdm]

I have tried everything : 1) Non-conformal mesh. 2) Disabling the on to one pairing 3) making the two edges from the beginning. It always run for some time steps (either 5-10 or even 900 depends on which solution from the above-mentioned I followed) but always gets to the same error (The node numbering changes though in every error). The even more strange incident is that this error only persists on my finer mesh (since I am trying to do a grid independence study). For the medium and coarse sized meshes, the periodic boundary condition works perfectly for the total of timesteps I want to run the simulation. 

Any further support would be much appreciated.

[Federico Alzamora Previtali]

See if the Auto Compute Offset works better than assigning the offset manually.

6.12. Modifying the Mesh (ansys.com)