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jaber June 12, 2009 17:35

icem hexa mesh parts pb
Hello dear colleagues,
I’m simulating a flow over a symmetrical NACA airfoil using,to have a multiblock structured mesh, I have done a 2d extruded mesh using ICEM HEXA(v11).the steps followed are:

1-generating 2d geometry (airfoil+rectangular domain) using a scripts file. creating parts representing geometry families.
2-2d blocking (several operations) and 2d mesh.
3-extruding (1 layer) the 2d mesh after converting to unstructured mesh.

Results: having a 2d extruded mesh. But parts still representing lines and not sides. making pb to introduce boundary conditions (inlet,outlet,wall and airfoil).

please, I will be grateful to receive any idea or suggestions.

PSYMN June 15, 2009 09:49

were your line elements turned off or not selected?
In 2D to 3D, line elements become shells, points become lines. So, if you had line elements around the perimeter of your 2D model, they would become shells when you extruded to your 3D model. Perhaps you had the line elements off and selected only the 2D shells and 0D nodes for extrusion? This would give you volume elements and line elements, but not shell elements…

PSYMN June 15, 2009 09:52

Check edge associations
One other possibility is that when you created the blocking, you did not associate all the edges to the curves. This is a common mistake, particularly with the straight far field boundary (people don’t think they need to because it already looks right). Surface projected edges do not create line elements when converted to unstructured mesh, which means you wouldn’t have anything to convert to shells in 2D to 3D.

The fix is to go back to your blocking step and make sure to set up associations for all your perimeter edges… Then continue with your previous process.

jaber July 5, 2009 06:23

thanks Simon.the second one helps well.
but there is a pb whith some lines and shells that need not to be(on profile part,and top part).

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