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Old   March 25, 2008, 07:26
Default non-positive volumes in mesh
Muhammad Usman Qureshi
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I have some non-positive volumes in my volume mesh. i am trying to run an inviscid simulation. Will this cause some error and will it cause Fluent to stop.

Many Thanks,
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Old   March 25, 2008, 09:46
Default Re: non-positive volumes in mesh
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I think that you've got to review the mesh, maybe there are some curve surfaces wrong meshed. Try to look your geometry with the shade option in gambit to control if there are surfaces that look "strange"
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Old   March 26, 2008, 09:46
Default Re: non-positive volumes in mesh
Daniel Tanner
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Most problems occur because of a poorly defined initial surfaces. Check these, paying particular attention to areas of high curvature.

Are you using a prism layer? Check to see if the prism is collapsing (use smaller elements and see if the problem persists). You could try creating a mesh with no prism layer, just to see if it is boundary elements are causing the problem.

Are you using TGrid or Gambit? You can use the "examine mesh" button in Gambit (the magnifying glass on the bottom right of the Gambit window) to see where the problem elements are located. Try creating finer meshes and see if the problems persist and if they occur in the same locations. In TGrid you can do the same using "display-> grid".

Hope this helps.
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Old   March 28, 2008, 16:57
Default Re: non-positive volumes in mesh
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Could try increasing your spacing in the meshing procedure. Is your model geometrically very complicated?
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Old   April 1, 2008, 11:45
Default Re: non-positive volumes in mesh
Míša Milakovová
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Hi, I had the same problem with 3D mesh. I moved all volumes to positive axis. So, try it too.
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