Autodesk CFD FSI using ANSYS Workbench

[Anonymous]

I am currently attempting to utilize this software's capabilities to write out pressure results to an FEA deck. I noticed that while the program does work with ANSYS, it writes the files to ADPL formats, which are rather antiquated. Workbench itself doesn't natively, at least on the surface, use these file formats. Within workbench, I attempted to write the files out to the formats needed (to read them back in at a later time), which worked, but CFD can't properly create the FEA decks even with the correct file formats. The main question is whether or not Autodesk CFD can even work with ANSYS workbench and if so, what are the proper steps to setting it up? I did follow the instructions given on how to output files for FSI, but it is possible I am doing something wrong. However, without knowing whether or not it is even possible, I don't want to keep troubleshooting. Thanks!

[bob.schlosser]

Are the steps you are referring to those in the help topic below?

http://help.autodesk.com/view/SCDSE/2019/ENU/?guid=GUID-C18AFA98-D9D9-45D0-B5A5-A006DD91285A

[Anonymous]

Yes, that is the guide.

[KubliJ]

Hi @Anonymous,

I don't have access to Ansys Workbench, so I don't know how much I can guide you on the issue.  I have though tested the process with Nastran and FEMAP and there were some issues with the tool.

I could not get it to work with Nastran.  Nastran requires a dummy pressure load to be defined on surfaces you want to update with pressures from CFD.  The process didn't work right and an issue was logged with the dev team to look at.  As of right now, this has not been resolved.

I was able to get FSI to work with FEMAP though.  But I had to apply an awkward workaround to get it to work.  While CFD does support directly updating the FEMAP file, it too did not work.  It would create the new FEMAP file, but it wouldn't actually write the pressures.  What I had to do was export the FEMAP model out as a Nastran file, then reimport that into FEMAP.  This converted the surface pressure to a element face pressure.  From that CFD was able to write the pressure load.

Have you tried following the workflow in the help?  Are there errors or failures of things to progress/happen?  We can try working this out together.

Thanks,

James

[Anonymous]

Hey James,

Thanks for the response. I did indeed tried walking through the steps laid out in the help topic. However, it wasn't till I had tried a bunch that I noticed that it was elemental pressure (nodal won't work?), which might be my problem. Similar to you, I had to export the FEA results from Workbench to the correct files formats, then map the results using CFD. Then I was planning to import them back into Workbench. I could select the correct files formats in the CFD export to FEA window, but it was here that it would fail. I can continue attempting to try and map the results, but I wanted to check if it was actually possible as I have spent a good bit of time trying to get it to work. As I mentioned, I think it might be an issue of getting the boundary conditions in Workbench as elemental and not nodal. The other possibility and one that likely isn't fixable is if the export to ADPL formats from Workbench aren't actually creating a file that CFD can properly map to, even if it is the correct file format.

Based on what you had to do, I wonder if I might get it to work if I am able to write out a Nastran file from Workbench and then write it back in after mapping. I'll have to look into that. I will be able to mess around with it some more next week, so I will keep you posted on my findings.

Thanks!

Tim

[Anonymous]

So I haven't gotten it to work yet, but it might be because ANSYS workbench doesn't really output files with the pressure loads. I have been simply exporting and then immediately importing files back into workbench (using several different file extension types). No matter what I do, the files don't seem to have load data. The only thing that exports and imports properly with the mesh is the fixed support BCs while the pressure loads clearly don't. If this is the case, there isn't any predefined load for the FEA deck to properly overwrite to begin with. I am currently trying to find out if it is even possible to get ANSYS to export the loads with the file types I am trying to use. If it can't, then this is likely the reason (or at least one of them) I haven't had any luck superimposing the FEA decks from CFD.

[KubliJ]

Hi @Anonymous,

How did it go, were you able to get CFD to update a workbench analysis model?

Thanks,

James