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Active Contributor
Sultan9009
Posts: 34
Registered: ‎06-19-2012

Divergence error

142 Views, 5 Replies
07-01-2012 07:10 PM

How do I prevent a divergence error? I check the meshing size and made sure the bc was not too complex. I still get diveregence error. What to do?

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Employee
Joey.X
Posts: 259
Registered: ‎06-14-2010

Re: Divergence error

07-02-2012 07:18 AM in reply to: Sultan9009

Could you make it clear divergence in which analysis type? Since you asked question in fluid analysis, the divergence usually comes from (top are more common)

- Improper/illegal boundary conditions 

- Over-constrained boundary conditions 

- Poor mesh quality

- Too large time steps for unsteady analysis



 

Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
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Active Contributor
Sultan9009
Posts: 34
Registered: ‎06-19-2012

Re: Divergence error

07-02-2012 07:32 AM in reply to: Sultan9009

I am doing steady fluid analysis. I uploaded the model as reactor 7 in dropbox. Can you see if I made a mistake.

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Employee
Joey.X
Posts: 259
Registered: ‎06-14-2010

Re: Divergence error

07-02-2012 10:48 AM in reply to: Sultan9009

hi, Asif,

 

I tried your most recent model reactor7.fem from dropbox, I put the fluid material to Air and turned on "turbulence" from setup/parameter/load curve tab/turbulence (change from 0 to 1). It solves, refer to attached images.

If the flow is turbulence flow (user needs to estimate the Reynolds number) , the turbulence has to be turned on , otherwise it may introduce the solution stability issue. 

PS, I have uploaded the modified model (with results) into your dropbox.

Regards,

Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
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Active Contributor
Sultan9009
Posts: 34
Registered: ‎06-19-2012

Re: Divergence error

07-03-2012 07:48 AM in reply to: Sultan9009

Hi Joey

 

I tried doing the analysis my self because I uploaded the model you saved from my dropbox but the results did not saved. I change the turbulence number to one. However, I still get a divergence error. How do you put the fluid material to air?

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Employee
Joey.X
Posts: 259
Registered: ‎06-14-2010

Re: Divergence error

07-03-2012 08:52 AM in reply to: Sultan9009

From FEA Editor/design scenario i/tree view/Parts/Part i/Material, right click to assign material/Edit material, 

you can select material from material library /or edit existed material properties.If you see any RED cross, that indicates the model is not ready (incomplete). 

I have uploaded the .zip file to your drop box, you can simply download/unzip it, and click .fem file to open the model in SIM/MP software, I have finished run for this model and the settings/results are complete.  

 

 

Jianhui Xie, Ph.D
Principal Engineer
MFG-Digital Simulation
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