Help with flutter examples

[Bryan Rea]

I'm trying to do some flutter analysis for subsonic regime with CAERO1 y PAERO1, but I haven't found any examples to follow. written in python, because I found the bdf complicated to modify by myself

No one in my university have ever worked with Nastran

Thanks!

[Steven Doyle]

I would definitely start with a simple statics and modal problem first.  There’s no much point in doing flutter until those work.

PyNastran doesn’t do flutter for you.  It can help you setup decks and validate them, but you still need to go through the aero manual and define your aero panel.  It’s got a good way to define an FLFACT sweep and post-process results, but there aren’t really examples of it outside of unit tests.  PyNastran very much assumes you know Nastran and have the QRG handy.

--
You received this message because you are subscribed to the Google Groups "pyNastran Discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pynastran-disc...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pynastran-discuss/e640a6c4-52c2-4b39-941d-a188c965a4b9n%40googlegroups.com.

[Bryan Rea]

I've done modal and static analysis in patran but not with pynastran, mainly I have problems with connection between my structural and aeropanel t with splines. I've read the Nastran aeroelastic and patran flightloads but I haven't found a way to those work. I'll give it another read though. 

Thanks Steve I really found your code helpful. 

[Steven Doyle]

Static aero has more severe aero requirements than flutter and I think static aero is much harder than flutter.  The aero mesh/spline density of that static aero bwb model is plenty for that vehicle. 

Assuming you use PKNL, the FLFACT cards are straightforward outside of the density card (it’s M/L^3 regardless of MAT1 density units) and going too fast will cause segfaults.

The harder part of aero is the SUPORT card, which you use to “constrain” rigid body modes.  If I had to guess, that’s your issue.  You can test that with a modes run.

To view this discussion on the web visit https://groups.google.com/d/msgid/pynastran-discuss/ee42eebd-3b5f-4a00-beda-16465f2f4390n%40googlegroups.com.