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-   -   [ANSYS Meshing] 2-way FSI of abdominal aorta and stent (http://www.cfd-online.com/Forums/ansys-meshing/117915-2-way-fsi-abdominal-aorta-stent.html)

milasko May 17, 2013 06:07

2-way FSI of abdominal aorta and stent
 
4 Attachment(s)
Hello.

I am trying to conduct 2-way FSI of abdominal aorta and stent by coupling FLUENT and Mechanical. The goal is to solve CFD in FLUENT for blood and then transfer pressures to tissue wall in Mechanical and then to stent.
I got CT images from hospital in my town. I have reconstructed models of aorta and stent in stl format. I converted stl files in CAD format using CATIA software (see attached picture).
Tissue is modeled as shell. I have imported geometry of tissue and stent in ANSYS Meshing using mixed resolution. I choose Mechanical from Physics.
Because the geometry contains shell and solid bodies I choose selective meshing method in which bodies need to mesh one by one. First I have meshed tissue. The problem appeared when I try to mesh stent. Two messages appeared. I have attached pictures for them. Also I have attached picture of tissue`s mesh.

Does somebody have a solution for this problem?

oewnce932c May 17, 2013 08:30

try to create a virtual topology, if you have on some element a lot of faces.
Model-> create Virtual Topology.(need to be active)
Select faces and create new topology cell. that will delete unseful edges from your geometry. Mesh will have more freedom.

milasko May 17, 2013 09:42

When I form different CAD model from the bodies and mesh them I get good mesh. At that time I don`t have problem meshing the stent.
I will try with your suggestion. I forgotten to say in first post that I am using tetrahedrons for meshing the stent and triangles for meshing tissue.

Thanks.

sarangdalne May 20, 2013 11:41

Hello,

Your stent body has lot of small slivers. Its recommended to use Virtual topology in this case and merger those small slivers into larger facets. Also, I would recommend you to check the defeaturing tolerance, in case you don't want to use virtual topology.
Just curious: which size function are you using to mesh this model?
Please let me know if you have any question.
Regards,
Sarang

milasko May 20, 2013 15:00

Dear Sarang,

I have tried with virtual topology, but it occupy too much RAM memory and then I can`t mesh my model. I get information "Not enought memory for meshing" or something like that. I have 8 GB of RAM. The virtual topology consume about 6 GB of RAM.
For ASF I used Curvature, Relevance Center - Medium, Smoothing - Medium, Span Angle Center - 18 deg, Min Size 2.0e-2 mm.
For meshing geometry which consist of stent only I used 0.5 mm for Body size and I got acceptable mesh.

Do you have any suggestion?

Regards

saeed bahrami July 22, 2014 15:52

hi milasko
 
hi milasko
i want drew figure 3
similar figure 1,2
i want to bend body in figure 3 similar figure 1,2.
how to bending????
please help me
thanks a lot

saeed.bahrami91@yahoo.com
http://www.uplooder.net/img/image/35...f/Untitled.png

milasko July 23, 2014 06:56

Hi saeed.

I don`t now how to bend flat surface into curved in Design Modeler. For my stent I have used CATIA. There is an option called "Develop". It can been found in "Wireframe and Surface Design" module.
I hope this helps you.

Regards!

saeed bahrami July 23, 2014 07:33

hi milasko
 
I'm working ANSYS-CFX.
ok
Thank you for your attention


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