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March 2, 2012, 06:50 |
an error in fine
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#1 |
New Member
Xiangjun Li
Join Date: Feb 2012
Posts: 1
Rep Power: 0 |
I created grids of a rotor, but when I started euranus, an error occurred as flows:
[INDEXERR] Illegal index(0) for collection with 0 element this error occurs only when I use "I" type grids.If I change "HOH" Grids ,the euranus is ok. And it is strange that if I import the CGNS file of "I" grids to CFX , it works well,too. So I wonder why this error occurs? Can you help me?? Thanks ~ |
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March 23, 2014, 06:13 |
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#2 | |
New Member
mohsen rahmani
Join Date: Mar 2014
Posts: 14
Rep Power: 12 |
Quote:
and the other problem that i have is when i solve a centrifugal compressor in Fine Turbo of Numeca with spart-alarms i have output but when i use another one, i have negetive domain density,pressure can any one help me with this problem? |
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March 25, 2014, 04:09 |
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#3 |
Senior Member
Hamid Zoka
Join Date: Nov 2009
Posts: 282
Rep Power: 18 |
Dear All;
regarding the grid type, note that "I" type is not flexible and can only be applied to limited types of blades. the best configurations are HOH and default topologies proposed by Numeca. This error generally arises when an improperly defined FNM (full non matching) boundary exist in the domain. Sometimes changing the number of streamwise grids may be a solution to this problem. regarding the turbulence model, I think "mohsenrahmani" is right. unlike the Spalart-Allmaras model, Euranus solver is not compatible with low-Re two equation turbulnece models such as SST. So if you wish to have a high resolution run with a better turbulence model, easily try other solver! Regards Last edited by Hamidzoka; March 25, 2014 at 11:56. |
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March 26, 2014, 03:41 |
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#4 | |
Senior Member
Colinda
Join Date: May 2012
Location: Brussels
Posts: 151
Rep Power: 13 |
Quote:
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March 26, 2014, 06:54 |
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#5 |
Senior Member
Hamid Zoka
Join Date: Nov 2009
Posts: 282
Rep Power: 18 |
Dear Colinda;
it is not matter of initial or boundary conditions. it has difficulties in convergence even in simple multi-stage simulations. if you have successfully used SST in such simulations please share your experiences with us. Regards |
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March 27, 2014, 02:08 |
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#6 |
Senior Member
Colinda
Join Date: May 2012
Location: Brussels
Posts: 151
Rep Power: 13 |
The centrifugal compressor tutorial in the FINE/Turbo documentation is one of the many examples of a case that was run successfully using SST model. Just give it a try. If you don't succeed to get it converged, your local support office will surely be able to help you correct the project to get it to run.
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March 27, 2014, 03:59 |
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#7 |
Senior Member
Hamid Zoka
Join Date: Nov 2009
Posts: 282
Rep Power: 18 |
My concern is mainly axial machines. are there validated cases with SST as well?
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March 27, 2014, 08:34 |
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#8 |
Senior Member
Colinda
Join Date: May 2012
Location: Brussels
Posts: 151
Rep Power: 13 |
Sorry, as "mohsenrahmani" was writing about centrifugal compressors I assumed incorrectly that you were working on similar configuration. The tutorial cases delivered with the latest release also include a multistage axial compressor case and a multistage axial turbine case. Both run well using SST, aiming for y+ values of 1 at the walls and setting the correct boundary conditions and initial values for the turbulence as recommended in the manual.
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March 28, 2014, 01:57 |
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#9 |
New Member
mohsen rahmani
Join Date: Mar 2014
Posts: 14
Rep Power: 12 |
thank you very much
my problem have been solved by increasing my mesh number in autogrid 4 about negetive cell |
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April 7, 2014, 09:10 |
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#10 |
Senior Member
Hamid Zoka
Join Date: Nov 2009
Posts: 282
Rep Power: 18 |
Dear All;
My problem with SST in axial flow machines was solved and I would like to share it with you! neither changing the number of cells nor solver settings resolved the problem. I got a converegd solution only through changing the topolgy of the mesh. It may seem strange but worked in my case!!! Regards |
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