Ansa Modeling and EFD.lab

Magr87 · September 27, 2011, 04:45

Hello together,

Actually i'm working with Ansa and EFD.lab and my Problem is that in Ansa i have a clean Model. But after the Output in Iges and opening with EFD it shows me about 600 faulty faces and 4820 gaps. What should i do?

vangelis · September 27, 2011, 07:20

Hi there,

One of the benefits of ANSA is its ability to handle non accurate geometry and apply topology based on specified tolerances.
This topology (connectivity information between Faces) however is not information that is stored in the IGES file.
As a result if you read the IGES file in another software you need to redo all the topology work again.
I am not familiar with the topology capabilities of EFD.lab but if it is not easy to fix the geometry there, I would recommend that you create a surface mesh in ANSA and the send it to EFD.lab.
I am sure EFD will be able to read mesh formats like NASTRAN or Fluent (or any other of the numerous formats that ANSA can output)

Hope this helps

Vangelis

Magr87 · September 28, 2011, 14:00

Hello, i try your proposition but have much more faulty faces. Can i clean my Model in EFD?

vangelis · September 29, 2011, 03:16

Hi,

My proposition, was to generate a surface mesh in ANSA and export this surface mesh (tesselated representation of the geometry) in EFD.

Do not output the Geometry (IGES) but output the mesh (NASTRAN or FLUENT or any format that EFD would read).

Best regards,

Vangelis

Boris_M · October 2, 2011, 10:36

Hi Magr87 and Vangelis,

IGES is not the best format to transfer data. I don't know about the features of ANSA like Vangelis, maybe there is a way to reduce the tolerance. There are issues with too large tolerances in CAD systems that might cause problems using it in other systems. If the tolerace is too big and IGES then has gaps between these surfaces try to reduce the tolerance if that's possible.
For FloEFD or EFD.Lab as it was called some time ago it is useful to use STEP as solid models often get holes due to IGES export/import complex geometry is often not very good imported.
Also FloEFD works with a unique meshing technology that doesn't allow to use common meshes as the solver is specialized in its use and stability to this mesh. Just like other CFD software cannot handle FloEFD mesh.
There is a possibility to heal the imported geometry but with the amount of bad faces and gaps I can imagine this doesn't work very well as there are too many variables.

I hope this helps,
Boris

September 27, 2011, 04:45	Ansa Modeling and EFD.lab	#1
Magr87 New Member Join Date: Sep 2011 Posts: 4 Rep Power: 14	Hello together, Actually i'm working with Ansa and EFD.lab and my Problem is that in Ansa i have a clean Model. But after the Output in Iges and opening with EFD it shows me about 600 faulty faces and 4820 gaps. What should i do?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Floworks vs EFD.Lab	Murat	FloEFD, FloWorks & FloTHERM	10	March 12, 2010 06:37
How does EFD.Lab solve the boundary layer?	Christiaan	Main CFD Forum	2	October 1, 2007 12:45

September 27, 2011, 07:20		#2
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	Hi there, One of the benefits of ANSA is its ability to handle non accurate geometry and apply topology based on specified tolerances. This topology (connectivity information between Faces) however is not information that is stored in the IGES file. As a result if you read the IGES file in another software you need to redo all the topology work again. I am not familiar with the topology capabilities of EFD.lab but if it is not easy to fix the geometry there, I would recommend that you create a surface mesh in ANSA and the send it to EFD.lab. I am sure EFD will be able to read mesh formats like NASTRAN or Fluent (or any other of the numerous formats that ANSA can output) Hope this helps Vangelis

September 28, 2011, 14:00		#3
Magr87 New Member Join Date: Sep 2011 Posts: 4 Rep Power: 14	Hello, i try your proposition but have much more faulty faces. Can i clean my Model in EFD?

September 29, 2011, 03:16		#4
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	Hi, My proposition, was to generate a surface mesh in ANSA and export this surface mesh (tesselated representation of the geometry) in EFD. Do not output the Geometry (IGES) but output the mesh (NASTRAN or FLUENT or any format that EFD would read). Best regards, Vangelis

October 2, 2011, 10:36		#5
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Hi Magr87 and Vangelis, IGES is not the best format to transfer data. I don't know about the features of ANSA like Vangelis, maybe there is a way to reduce the tolerance. There are issues with too large tolerances in CAD systems that might cause problems using it in other systems. If the tolerace is too big and IGES then has gaps between these surfaces try to reduce the tolerance if that's possible. For FloEFD or EFD.Lab as it was called some time ago it is useful to use STEP as solid models often get holes due to IGES export/import complex geometry is often not very good imported. Also FloEFD works with a unique meshing technology that doesn't allow to use common meshes as the solver is specialized in its use and stability to this mesh. Just like other CFD software cannot handle FloEFD mesh. There is a possibility to heal the imported geometry but with the amount of bad faces and gaps I can imagine this doesn't work very well as there are too many variables. I hope this helps, Boris