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-   -   [ICEM] 3D mesh of airfoil from 2D (segmentation violation) (http://www.cfd-online.com/Forums/ansys-meshing/93391-3d-mesh-airfoil-2d-segmentation-violation.html)

TKE October 13, 2011 14:00

3D mesh of airfoil from 2D (segmentation violation)
 
Hi everyone,

I have the following problem. I would like to create a 3D mesh around an airfoil, based on an already done 2D mesh. I tried to make it in two different ways, but I received the same error message. I have been struck with this problem for a week by now... :confused::(
The 2D mesh has 199972 cells, and the 3D mesh should have 199 972*50 = 9 998 600 cells.

Way 1
1) Convert to unstructured mesh
2) Extrude
3) Add to parts (by selecting elements)
4) Defining boundary conditions (velocity inlet, outflow, top and bottom symmetry, wall at suction and pressure side, and two periodicity)
5) Output to *.msh

Way 2
1.) Copy all geometric entities in spanwise (z) direction.
2.) Connecting them with the original entities
3.) Creating surfaces with these curves.
4.) Adding the surfaces to parts.
5.) Creating 3D blocks from the 2D blocks
6.) Associating them with the proper parts (surfaces)
7.) Adding material point (I was not sure, whether it is possible. I had FLUID already in 2D)
8.) Defining boundary conditions.
9.) Converting into unstructured mesh.
10.) Output to mesh (*.msh)
11.) Reading into FLUENT

I received the following warnings and following error messages:

"Building...
mesh"
"Warning: Inappropriate zone type (periodic) for one-sided face zone 21. Changing to wall"
"Warning: Inappropriate zone type (periodic) for one-sided face zone 22. Changing to wall"
"fluent 13.0.0 received a fatal signal (SEGMENTATION VIOLATION)"

I would be really graceful for any help, I'm stuck with this topic for a week, a spent a tons of time and energy, and I see no solution at the moment...:(

Regards,
TKE



p.s.: the error log,

/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x13c461d]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x13c4c43]
/lib64/libpthread.so.0[0x308960eb10]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(C_Centroid_Fast+0x2f4)[0x6aad44]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(Fill_Domain+0x348)[0x612598]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(Build_Grid+0xf71)[0x4be701]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x65cf67]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x7e5)[0x1405dd5]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x768)[0x1405d58]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x125b)[0x140684b]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x906)[0x1405ef6]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x14072f8]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval_errprotect+0x32)[0x1407382]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x2ef)[0x14058df]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x7b9)[0x1405da9]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x8bb)[0x1405eab]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x13c461d]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x13c4c43]
/lib64/libpthread.so.0[0x308960eb10]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(C_Centroid_Fast+0x2f4)[0x6aad44]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(Fill_Domain+0x348)[0x612598]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(Build_Grid+0xf71)[0x4be701]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x65cf67]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x7e5)[0x1405dd5]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x768)[0x1405d58]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x125b)[0x140684b]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x906)[0x1405ef6]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0[0x14072f8]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval_errprotect+0x32)[0x1407382]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x2ef)[0x14058df]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x7b9)[0x1405da9]
/share/apps/usr/ansys_inc/v130/fluent/fluent13.0.0/lnamd64/3d/fluent.13.0.0(eval+0x8bb)[0x1405eab]

TKE October 18, 2011 13:57

General problem
 
I did the 3D mesh in a 3rd way as well, and I always have the same warnings with changing periodicity to wall (even if I set in ICEM earlier periodicity in 0,0,1 direction.
On the other hand, segmentation violation occured again.

Probably it is one of the most general error, because if you type ICEM CFD and space in Google, then it offers "ICEM CFD segmentation violation"

I've read that it can be because of the lack of memory, or something else, but I simply have no idea which step is wrong, which I did...

TKE October 19, 2011 17:45

Topic closed
 
I give it up.

Basically I made the same 3D mesh in two main different ways: first with mesh extrusion, second with copy of geometric entities, creating surface, 2d to 3D blocks, associating, etc. I made them with several smaller edited way, but in all 4 cases I recieved the main two messages:
error: segmentation violation
warning: periodicity converted into wall (despite that I clicked at mesh/global mesh setup/set up periodicity/define periodicity/translational periodic, offset 0 0

My critical remarks on the software of ICEM CFD

1) If I copy a curve/spline translated in z direction, and try to connect it with the original spline, it generates a new surface, with very different curve. It should be a simple step, without violating my original geometry.

2) Segmentation violation is a kind of error message, which tells you nothing about the source of the problem. Too general.

3) It is not logic, why is not enough to set the BC of periodicity associated with a certain surface/part. Why is it necessary, to make extra (for me unknown steps) for really enabling periodicity for a certain surface.

4) I really do not like, that the solver is always set back to NASTRAN, even if I set FLUENT V6 earlier as default.

5) Last remark: converting(extruding/translating/whatever) a 2D geometry into 3D, with containing the same BC-s should be a simple, few-click complicated process. Even if there exist the necessery devices (mesh extrusion, inherit part, etc), something crucial is missing. I repeated this process at least 4-5 times, a spen a couple of 10 hours with working on it, without results.

I am sorry for this long post, but I am very disappointed with ICEM, because I expected it to be a relatively easy job. You have a 2D slice, you need the same mesh extruded, 2 new BCs (periodic), block extrusion, association that's all. Not at all.

Regards,
TKE

p.s.: Related threads:
http://www.cfd-online.com/Forums/cfx...c-problem.html
http://www.cfd-online.com/Forums/flu...em-fluent.html
http://www.cfd-online.com/Forums/ans...odeling-2.html
http://www.cfd-online.com/Forums/flu...le-fluent.html

BrolY October 20, 2011 03:21

I'm sorry but this looks like a FLUENT issue, unstead of an ICEM issue.
Unless you didn't assign well the faces with the good parts !

About your way 2 : you can use the tool Geometry -> Create / Modify Surface -> Curve Driven or Sweep Surface
It would be faster to create your 3D geometry from your 2D geometry than creating all the curves and points and surfaces !

Ammofreak October 20, 2013 07:07

found solution
 
I know it is kind of late, but i was facing the same problem (segment violation). Firstly I removed the boundary conditions on my periodic faces in ICEM CFD while exporting. I then made faces periodic in fluent by using command

grid
modify-zones
list-zones
and then see which zone do you want to make periodic

make-periodic

then enter required zone numbers

answer next questions and you will get the periodic conditions.


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