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-   -   Volumetric Control Problem (https://www.cfd-online.com/Forums/star-ccm/86688-volumetric-control-problem.html)

boathead March 30, 2011 09:02

Volumetric Control Problem
 
2 Attachment(s)
I would like to use a volumetric control in my computational domain to locally refine the mesh such that I can resolve the interaction of a series of coolant jets more accurately. The pink volume shape in the attached image shows the region where I want to add refinement to.

I am however having difficulty getting the volumetric control to work in my domain. I have encountered two issues:

1) STAR-CCM+ crashes when I try to put a vol ctrl in the domain and mesh it
2) If some how STAR-CCM+ doesn't crash then it generates an odd looking mesh such as the one attached.

I have tried changing blending function and growth factor and nothing seems to be working.

Any suggestions would be greatly appreciated.

Cheers

RobertB March 30, 2011 17:25

What version are you using?

Could you try extending the volume downwards a little, it looks like it is touching the surface, perhaps that is confusing it.

In general I have found volume refinement robust.

boathead March 31, 2011 06:54

I am using Version 5.04.008.

I have tried extending outside of the surface and inside and still do not get the desired effect.

RobertB March 31, 2011 09:03

I hate to suggest it but have you thought of trying 5.06/6.02?

Have you applied the volume refinement to surface/prism/volume?

Are their any other parameters, e.g. minimum mesh size - either local or global, that could be conflicting here.

Double check your CAD. Sometimes things like small steps in the CAD, where patches join, are ignored with large cells but when you refine the mesher tries to resolve them and that causes problems.

boathead April 1, 2011 13:17

My uni department has that version, and I have tried re-running the mesh but still have the same problem.

I have applied the mesh refinement to the surface remesher and volume mesh.

Checked the CAD for problems and can't seem to find any. I created the geometry in STAR so I don't think there will be too much of a problem in that area anyway.

Maybe it is something to do with my cell sizes. My global minimum size was 2mm, target size is 11.4mm and cell size in the volume shape was 2mm. I also used a blending ratio of 0.5.

RobertB April 1, 2011 13:46

Try making your global size say 0.5mm and see if that helps, it shouldn't but you never know.


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