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James_ May 26, 2013 11:26

yellow circle
1 Attachment(s)

Sometimes during tools use such as extrusion or grid solve you can see a yellow circle. What does it mean?


cnsidero May 27, 2013 09:58


For the elliptic smoothing, being an elliptic boundary value problem that uses an iterative method to solve, I believe the circle indicates the location of the maximum residual.

For the hyperbolic extrusion, being a hyperbolic initial value problem, I'm not 100% sure as each iteration represents the next layer in the mesh. Perhaps it's the location of maximum point advancement.

Someone from Pointwise is going to have to chime to give more scientific answer to your question.



Originally Posted by James_ (Post 430107)

Sometimes during tools use such as extrusion or grid solve you can see a yellow circle. What does it mean?


James_ May 27, 2013 14:06

Thanks, Chris

jchawner May 27, 2013 17:10


Chris is correct. For the elliptic PDE solver for a volume grid, the circle appears at the point of maximum residual.

I couldn't make the circle appear when doing Create, Extrude and am drawing a blank on what it could mean.

Are you running Pointwise or Gridgen?

James_ May 29, 2013 05:07

1 Attachment(s)
Thanks John for your answer.

Iím using Pointwise.
My little experience says: if you see a yellow circle during extrusion you will have problems in next steps:). But it is not a rule.
In the attached picture you can see a circle appears during extrusion operation. It would be nice to know what kind of problem is indicated by this circle:)

jchawner May 29, 2013 17:56

Well, that took longer than it should have. During extrusion, the yellow circle is centered on the point of the current front with the largest step size from its previous location. So I can imagine that large step sizes are the sign of divergence, although the image you show looks fairly benign.

One thing I'll advise is that if you're extruding structured grids using the normal (aka hyperbolic) method, always set the Kinsey-Barth smoothing parameters to a value of 3, especially if you have concave regions like the one shown above.

Also keep in mind that for the traditional extrusion solvers there's only so much you can do coming out of a concave corner like that. Our tech support can tell you which parameters to alter to get it out as far as you can.

James_ May 30, 2013 14:46

Thank you very much John:) especially for your hints about extrusion settings


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