CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   FLUENT (https://www.cfd-online.com/Forums/fluent/)
-   -   error with fluent for 2ddp (https://www.cfd-online.com/Forums/fluent/33968-error-fluent-2ddp.html)

yann June 15, 2004 04:30

error with fluent for 2ddp
 
hi

i made a 2D model of a kind of aerofoil with gambit. i am trying to see the flow over the aerofoil. i created a boundary layer on the skin and mesh the the rest of the space in triangle. when i run fluent and try to refine my grid in region i have a "warning: non positive volumes exist". it is a little bit odd considering the fact i was working in 2ddp. anyway, the refining is accepted, so i go on. when i run the iterations, i have the error: "divergence detected in AMG solver: pressure correction". can someone tell me what does it mean? and how to solve this.

thanks for all yann

kpodila@dal.ca June 15, 2004 11:02

Re: error with fluent for 2ddp
 
Hello Group, Even I face this. Could u please know how can it be cleared? Thanks

Bob June 15, 2004 11:03

Re: error with fluent for 2ddp
 
You get the error due to non positive volumes. This must be corrected before you can run your case. If you saved your case after you refined it and got the non positive error then you will have to start over unless you have the pre-refined case saved.

kpodila@dal.ca June 15, 2004 14:15

Re: error with fluent for 2ddp
 
what are those non positive faces? fow can one get rid of them? Are u ure AMG error is due to grid?

Bob June 16, 2004 10:06

Re: error with fluent for 2ddp
 
My experience is that once they are there you can't get rid of them no matter how much refining you do. So you must go back to the last saved mesh that didn't have non-positive faces and use that one. What has happened most likely and I found this on the fluentusers.com page is that the boundary layer you created and the mesh have overlapped due to refining. Also if you read in the tutorials it states that if you have non-positive faces or volumes you must resolve the issue and if you don't FLUENT cannot begin a calculation (page 1-6 FLUENT 6.0 tutorial manual).


All times are GMT -4. The time now is 21:10.