Problem importing watertight model into CFX

djk1301 · February 1, 2011, 20:54

I'm having problems importing a freeform model into CFX. The model is a nurbs based geometry modelled in Rhino. The model is checked for watertightness in rhino. The model is completely closed in rhino and encloses a closed volume. I exported it as IGES to CFX. When I open CFX-pre im getting this message:

CFX-Pre Application Error

ERROR
There was a problem importing the mesh from the requested file.
The importing process reported the following problem:

Model "Model" does not have a valid mesh associated with it.

Body B2997 is an unsuppressed surface body that does not enclose
a volume. Only 3D volume meshes can be imported. If your model
contains valid bodies as well as surface bodies then suppress
the surface bodies and remesh before continuing.

ERROR: Failed to export model.

So the geometry isnt a closed volume anymore. This happened somewhere when importing into CFX or exporting from rhino. Does anyone know how to fix it?

http://dl.dropbox.com/u/3559316/jpgs/3.jpg
http://dl.dropbox.com/u/3559316/jpgs/5.jpg
http://dl.dropbox.com/u/3559316/jpgs/4.jpg

scott · February 1, 2011, 21:33

Hi Daniel,

You are trying to import a 3D solid body into CFX-Pre, but CFX-Pre is expecting a Mesh file, not a body.

If you are using ANSYS Workbench you will need to import this into Design Modeller, or ANSYS Meshing to then create a mesh that you can import into CFX.

Hope this helps. I presume that you may have some additional issues with your simulation, so can I suggest that you look at the Tutorials and examples included in the Help menu.

Regards,

Scott

djk1301 · February 1, 2011, 23:00

Scott, thx you for your reply. However i did follow all the workbench steps. I exported from rhino as Iges. Then imported the .iges file in the design modeller. I meshed the geometry in ansys mesher. The problem i get then, that in ansys mesher says the Total volume = 0. If i then go to CFX-pre i get the error that i posted. That has something to do with the fact that my model is not watertight. This lack of watertightness happened somewhere in the export from rhino to IGES or in the import of the .iges file in the design modeller, I think.

scott · February 1, 2011, 23:04

hmm, for that I am not sure, maybe try to export as Parasolid or Step.

I also have had no luck with Rhino exports in the past (as STL) and have given up!

Design Modeler repair tools might be able to clean up the cad geometry. Use Repair Sliver Surfaces, Repair Spikes, etc etc.

Maybe import only solids, not surfaces and solids to see where any problems are.

Sorry I can't be of more help.

Regards,

Scott

February 1, 2011, 20:54	Problem importing watertight model into CFX	#1
djk1301 New Member Daniel Join Date: Feb 2011 Posts: 2 Rep Power: 0	I'm having problems importing a freeform model into CFX. The model is a nurbs based geometry modelled in Rhino. The model is checked for watertightness in rhino. The model is completely closed in rhino and encloses a closed volume. I exported it as IGES to CFX. When I open CFX-pre im getting this message: CFX-Pre Application Error ERROR There was a problem importing the mesh from the requested file. The importing process reported the following problem: Model "Model" does not have a valid mesh associated with it. Body B2997 is an unsuppressed surface body that does not enclose a volume. Only 3D volume meshes can be imported. If your model contains valid bodies as well as surface bodies then suppress the surface bodies and remesh before continuing. ERROR: Failed to export model. So the geometry isnt a closed volume anymore. This happened somewhere when importing into CFX or exporting from rhino. Does anyone know how to fix it? http://dl.dropbox.com/u/3559316/jpgs/3.jpg http://dl.dropbox.com/u/3559316/jpgs/5.jpg http://dl.dropbox.com/u/3559316/jpgs/4.jpg

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Problem in Buoyancy Model?	dhrubo	CFX	3	June 5, 2010 06:32
Polyflow Simulation with ViscoElastic Model memory problem	sid2909	FLUENT	0	May 10, 2010 06:29
Polyflow Simulation with ViscoElastic Model memory problem	sid2909	ANSYS	0	May 10, 2010 06:27
CFX - Evaporation problem	AlessandroD	CFX	0	August 18, 2009 07:03
Importing mesh problem	ParodDav	CFX	1	May 14, 2007 19:15

February 1, 2011, 21:33		#2
scott Member Scott Join Date: Sep 2009 Posts: 44 Rep Power: 17	Hi Daniel, You are trying to import a 3D solid body into CFX-Pre, but CFX-Pre is expecting a Mesh file, not a body. If you are using ANSYS Workbench you will need to import this into Design Modeller, or ANSYS Meshing to then create a mesh that you can import into CFX. Hope this helps. I presume that you may have some additional issues with your simulation, so can I suggest that you look at the Tutorials and examples included in the Help menu. Regards, Scott

February 1, 2011, 23:00		#3
djk1301 New Member Daniel Join Date: Feb 2011 Posts: 2 Rep Power: 0	Scott, thx you for your reply. However i did follow all the workbench steps. I exported from rhino as Iges. Then imported the .iges file in the design modeller. I meshed the geometry in ansys mesher. The problem i get then, that in ansys mesher says the Total volume = 0. If i then go to CFX-pre i get the error that i posted. That has something to do with the fact that my model is not watertight. This lack of watertightness happened somewhere in the export from rhino to IGES or in the import of the .iges file in the design modeller, I think.

February 1, 2011, 23:04		#4
scott Member Scott Join Date: Sep 2009 Posts: 44 Rep Power: 17	hmm, for that I am not sure, maybe try to export as Parasolid or Step. I also have had no luck with Rhino exports in the past (as STL) and have given up! Design Modeler repair tools might be able to clean up the cad geometry. Use Repair Sliver Surfaces, Repair Spikes, etc etc. Maybe import only solids, not surfaces and solids to see where any problems are. Sorry I can't be of more help. Regards, Scott