Problem Updating Geometry - CFD 2018

[nathan.alday]

I've recently started having problems updating geometry in CFD 2018.  It gets as far as "Performing Diagnostic Sweep", and then hangs - I have to abort the program.  The design is then corrupted.  I read in the "Latest Updates" sticky that there's a known issue with complicated models, but I'm even having problems with very simple, one-part models.

I'm updating the geometry in Inventor 2017 professional.

Any suggestions?

- Nate

[marwan_azzam]

Hello Nate,

An inventor 2017 model should be able to open in CFD 2018 without a problem.

Did you, or can you, try the following:

1- Start CFD and bring in the model directly through File: New.  This is to say create a new model rather than updating an exciting one.

2- Save the geometry in a neutral file format such as ACIS (*.sat) and try to update design (or create a new model) using that.

3- Repair the installation of both, Inventor and CFD, through Windows Control Panel Programs and Features.

Are you working with files across the network or everything is on your local hard drive?

Let us know.

Marwan

[nathan.alday]

I don't have any issues creating new models from Inventor - it's only when I try to update existing CFD geometry from Inventor (even if I don't actually change anything in the Inventor geometry, but try to "update design study").  CFD actually sent an Autodesk crash report on one of the attempts - so hopefully that can be useful for you.

We uninstalled/reinstalled CFD 2018 this morning, and it didn't fix the problem.

I've tried doing the model update from both local and network Inventor models - but the results appear to be the same.  I've tried running complex models, as well as simple parts - with the same results.

Doing a manual update of the geometry using a SAT file seems to work geometry-wise (i.e. the geometry comes in successfully) - but I lose all of my boundary conditions, materials, etc. - so it isn't any better than creating a whole now model.

I can talk to my IT guru about repairing Inventor 2017 - but the problem seems to happen within the CFD processes - and none of my other 3D programs appear to have a problem with the Inventor 2017 geometry.

Thanks for the help,

- Nate

[nathan.alday]

...and I'm not sure if this is relevant or not - but another quirk I've noticed with CFD 2018 is that it crashes every time I launch it - unless I've started Vault first (I don't even have to log-in - I just need to launch it).  I've learned to deal with it, but thought I should mention it.

- Nate

[Amal.C]

Hi @nathan.alday,

Thanks for reaching out 🙂 

I understood that you are updating the design by importing the new CAD directly from CFD "Add/Update Design". Correct? 

Did you try to update the design from Inventor using the CAD Connection (Add-ins > Simulate in CFD > update design study)? 

The issue may be caused by a low value of tolerance. Did you try to turn on the flag AsmCointol and increase the value of the tolerance to 0.01 for example?

Thanks,

Amal

[nathan.alday]

Amal - thanks for your follow-up.

The problem only occurs when trying to update geometry directly from Inventor.  The exact same geometry comes-in fine from Inventor if I'm starting a brand new analysis.

The geometry update from within CFD was a work-around that was suggested (which works for the geometry - but unfortunately purges all of the analysis settings:  materials/BCs/etc. - so it's like starting from scratch anyway).

I'll try tweaking AsmCoinTol flag value - although (as I mentioned above) the geometry imports fine as a new design.

- Nate

[agaston]

I am having the same exact issue as Nate, I clone an existing Design Study, save and close the CFD application, then attempt to import new geometry into the cloned Design study directly from Inventor and the CFD application crashes.  I attempt to open the file and it again crashes immediately unless I delete the cloned Design Study file in Windows explorer, once I delete the Design Study file, the cfd file will open with no issues. 

I am also able to update a Design file from within CFD, but like Nate has mentioned this does not carry over any material props, boundary conds, etc.  which defeats the purpose of cloning.

I am also able to create a new Design Study from Inventor with no issues as Nate mentioned.

I have had this issue since using CFD 2018, I do not want start from scratch every time I make a small change to Geometry.  I would like to be informed if and when a solution is found.  Thanks.

[nathan.alday]

Depending on the type of tweak you're trying to do, I have a work-around that might be helpful.

If I have baffles, vents, or other geometry that I think I might want to evaluate (but aren't sure yet), I'll bring the features in with the model from the start, and assign them the air material.  Then it gives me the option of adding shell elements to surfaces (or making the material solid) if I want to experiment.  Unfortunately it's not ideal (and can really drive-up the element count), but it's sometimes better than completely recreating the analysis every time (especially if I have a lot of boundary conditions).

- Nate

[David.Short.]

Hi @agaston,

This is an interesting problem and one which I have not experienced when carrying out the same process.

Do the geometry modifications that you make influence the surfaces on which BCs are applied?

Please share a .zip file with a .cfz plus the geometries which induces the problem.

All the best,

David

[agaston]

Hi David, 

I am currently working with support on this issue, they confirmed the problem yesterday morning and I have sent the files you mentioned so they can work the problem from their end.

Thanks for your quick response and willingness to help, though.

Regards, 

Aaron

[David.Short.]

Ok great. Let us know the solution here once it s found!

Thanks,

David

[agaston]

After working with Autodesk Tech support they found that there is a Development Defect already filed with with the 2018 CFD application.  My support case was added and is being investigated by the development team.

I was able to find a workaround that works for the most part.  To import geometry into a new design study, import within the CFD application, selecting Add/Update Design in the Setup menu, browse for the Inventor file, then Create New Design.  This will pull in Geometry without losing part names from Inventor.  You can assign materials and boundary conditions, if you have geometry changes after assigning these properties.  Make the geometry changes, then within the CFD application use the same process as before, except you update the design study.  In the Setup menu select ADD/Update Design, browse for the inventor file, then update the design.  All materials, B.C.'s, mesh etc. is retained and software does not crash.

This process worked most of the time, but seemed to fail if there were major Geometry changes.  Still trying to figure it out, but this could save some time when making small updates to geometry.

I will post any updates as they become available.

[agaston]

A year and a half later after downloading Simulation CFD 2019 the software still crashes when attempting to update geometry.  I updated a 2018 design study to 2019 and the software crashes when trying to update the geometry.  The 2019 seems to have more problems than I had with 2018 therefore I have been working in 2018.  This is forcing me to assign materials and boundary conditions everytime I make a small geometry change.  Very frustrating.