cyclic boundary conditions

lost.identity · March 3, 2013, 13:55

Hi, I'm trying to create cyclic boundaries for an axisymmetric cylinder with swirl. I made it only 1-cell thick (with 1 degree angle). I seem to get errors every time I try to set cyclic BCs.

I created two cyclic boundary surfaces and then try to match them. The way I create these cyclic boundary surfaces is by using the option "Create by picking surface based on Vset". What I essentially did was to select a cell on one side to create one cyclic surface and I did the same thing for the other side. I matched them next, which doesn't give me any errors. But it gives me a huge list of errors when I try to save the geometry file. Is there a simple way to do this without selecting vertices?

Pauli · March 4, 2013, 10:04

Sounds like you correctly created the cyclic pairs - first make two cyclic regions then cymatch the two regions.

What are the errors?

lost.identity · March 5, 2013, 08:53

Thanks for the reply Pauli. I started all over again and now I'm able to save the file without any errors. Previously, I got the following error many times when I try to save the geometry.

Code:

 **ERROR - CYCLIC BOUNDARIES 36000 AND 72000 ARE IN CYCLICS 
1, 36001, 72001, 108001, 144001

When I was doing this before I deleted the cyclic boundaries I had defined earlier but I guess they didn't get properly deleted, so I re-did the mesh again and created the boundaries again.

March 3, 2013, 13:55	cyclic boundary conditions	#1
lost.identity Senior Member Join Date: Apr 2009 Posts: 118 Rep Power: 17	Hi, I'm trying to create cyclic boundaries for an axisymmetric cylinder with swirl. I made it only 1-cell thick (with 1 degree angle). I seem to get errors every time I try to set cyclic BCs. I created two cyclic boundary surfaces and then try to match them. The way I create these cyclic boundary surfaces is by using the option "Create by picking surface based on Vset". What I essentially did was to select a cell on one side to create one cyclic surface and I did the same thing for the other side. I matched them next, which doesn't give me any errors. But it gives me a huge list of errors when I try to save the geometry file. Is there a simple way to do this without selecting vertices?

March 5, 2013, 08:53		#3
lost.identity Senior Member Join Date: Apr 2009 Posts: 118 Rep Power: 17	Thanks for the reply Pauli. I started all over again and now I'm able to save the file without any errors. Previously, I got the following error many times when I try to save the geometry. Code: *ERROR - CYCLIC BOUNDARIES 36000 AND 72000 ARE IN CYCLICS 1, 36001, 72001, 108001, 144001 When I was doing this before I deleted the cyclic boundaries I had defined earlier but I guess they didn't get properly deleted, so I re-did the mesh again and created the boundaries again. Last edited by lost.identity; March 5, 2013 at 09:10.*

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March 4, 2013, 10:04		#2
Pauli Senior Member Pauli Join Date: Mar 2009 Posts: 189 Rep Power: 17	Sounds like you correctly created the cyclic pairs - first make two cyclic regions then cymatch the two regions. What are the errors?