Cracks in 3D contour plot

- December 9, 2019 at 2:24 pm
  
  Bergheden
  Subscriber
  
  Hello.
  
  I have made a CFD model in 3D, to simulate airflow in large industriel buildings. This has first been done in 2D without any problems, but when switching to 3D i encounter a problem. The contour plots seems to have "cracks" which results in the XY-plot for velocity being incomplete. This happens no matter how fine or course the grid is. Have any of you experienced this, and if so found a solution?
  
  The turbulence model used is k-epsilon with "standard wall treatment".
  Methods used is SIMPLE.
- December 9, 2019 at 4:22 pm
  
  DrAmine
  Ansys Employee
  
  Double check graphics and driver. If all run a single iteration with zero as number of cpus
- December 10, 2019 at 7:55 am
  
  Bergheden
  Subscriber
  
  Double check graphics and driver. If all run a single iteration with zero as number of cpus
  
  Hello Amine.
  
  I have tried what you suggested and it seems to work, but is there a long term solution? With only one iteration, the model is far from converged, and without parallel processing, the total processing time is extremely long.
  
  Best regards,
  
  Oliver
- December 10, 2019 at 3:16 pm
  
  Rob
  Ansys Employee
  
  The cracks are probably related to the parallel partitions and can usually be ignored: they just affect the images.
  
  Not seen that issue with a line graph, how does it look if you plot against position (x, y or z)?
- December 10, 2019 at 4:59 pm
  
  DrAmine
  Ansys Employee
  
  And make a screenshot of the contour panel.
- December 11, 2019 at 10:14 am
  
  Bergheden
  Subscriber
  
  Update:
  The problem seems to be with the parallel partitions as rwoolhou mentions. I have now tried simulating with serial, and that seems to solve the problem completely, both the cracks in the contour plot and the issues with the line graph. This has been tested with multiple models and seems like a consistent solution. Thanks for the input both rwoolhou, and Amine
  
  - Oliver
- December 11, 2019 at 6:01 pm
  
  DrAmine
  Ansys Employee
  
  Nice
  But does it still happen in parallel?
- December 12, 2019 at 7:32 am
  
  Bergheden
  Subscriber
  
  Yes, i does. I've tried in multiple CFD-models, and even with different versions of ansys (19.1, and 2019 R2). This seems to be consistent, at least for my case in 3D. No problems with serial so far.
  
  - Oliver
- December 12, 2019 at 1:00 pm
  
  DrAmine
  Ansys Employee
  
  Then please as I asked before: make a screenshot of the contour panel. I want to see the settings there.
- December 12, 2019 at 2:50 pm
  
  Bergheden
  Subscriber
  
  I this what you are asking for?
  
  - Oliver
- December 12, 2019 at 4:25 pm
  
  DrAmine
  Ansys Employee
  
  Ok that is the issue: better to create a new surface zone (search for it in Fluent new search feature. Probably under domains if you follow the ribbon) for the domain and color that.

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