Need 2D axisymmetric tutorial

[dkusmer]

I can not find an Autodesk Simulation CFD tutorial for 2D axisymmetric. It would be nice to have a complete tutorial from geometry creation (2D surfaces which require patches) to how to do boundary and initial conditions on 2D axisymmetric geometry (i.e. edges) to the proper 2D axisymmetric switches (input?) for meshing and solving, to displaying 2D axisymmetric results (including pseudo 3D representation). Does anybody have a link to such a tutorial?

Thanks, Dan

[Jon.Wilde]

Hi Dan,

In the absence of a tutorial, here are a few pointers:

• You do need to ensure that your model is in the x-y plane and along one of the axes (as this will be your symmetry line). It cannot cross this axis
• The 2D surface depends on the model, but needs to be a slice through the centre - and just the top/bottom half of this as you are going to revolve it around your chosen axis
• Materials and Boundary Conditions are as per the 3D models, although Volumes become Surfaces and Surfaces become Edges
• Meshing is up to you, typically we move to a 2D model so that we can use far more mesh. Honestly I usually start with a pretty fine mesh and that usually does it!
• The results are often the hardest part. All we can really do is shade by differeny results (by chaging the global settings)
• I am pretty sure you can still use most of the plane functions also, the bulk calculator is still very useful for instance
• You can also still view vectors, using the global settings again

Does that help at all?

Thanks,

Jon

[dkusmer]

Jon,

Thanks very much, your response does help. In the meantime it was pointed out to me that the "Bullet" tutorial is an axisymmetric problem which also helps.

Right now I'm spending an inordinate amount of time trying to figure out how to create 2D axisymmetric assemblies in Inventor, what are the best surface types to use for Simulation CFD, best way to get the surfaces into Simulation CFD, and how to make the assembly associative.

I never had 2D training but what I found out so far is that patches seem to work the best although I'm having trouble when edges overlap between parts. "Launch Active Model" from Inventor seems the best way to get the surfaces into Simulation CFD. I haven't figured out how I can change the assembly in Inventor (example: make a 2D part longer) and be able to update it Simulation CFD. Any further assistance would be greatly appreciated.

Thanks, Dan

[Jon.Wilde · Accepted solution]

Hi Dan,

My approach would be to keep things simple. Work in an assembly, create one sketch and surface patch (this is the 2D surface you will read in) per part and then move on to the next part. Avoid multibody parts if possible, I have seen issues reading them in when they are surfaces.

Edges should not overlap between parts. 

Launching Active Model is correct. Once you have the Design Study Manager open, you can always just expand one of the previous models, click on the design you wish to update and then 'Update'. Rather than just launching.

Hope that helps.

Jon

[dkusmer]

Jon,

Thanks for your responses and suggestions. They've been a big help.

Regards, Dan

[Vish777]

Good day,

I have tried using the above approach. My model ias built in the X-Y plane with X being the symmetric axis. I then patched the curves to create a surface. However if I try to apply a BC or load it cannot select anything.

Am I missing a step?

Thanks,

Vish

[Jon.Wilde]

Are you applying the BC's to an edge? Should be OK so long as you have a 2D surface only in CFD.

Did you also right click on the 'Geometry' text in CFD to set the x-axis as the axis?

[Vish777]

Hi Wildej,

Ok Slight correction...

I have built a simple 2D sketch on Autodesk Pro 2015. Then I patched it so it looks like a surface and it selects it as a surface as well.

I then go to the enviroment tab to select Stress analysis. I would like to apply a pressure to a curve with BC on the edges.

Now from your post it says only in CFD. Does that mean i cannot do this for a static Stress analysis?

[Jon.Wilde]

Ah, now I understand. This is the Simulation CFD forum - it sounds like you are using Inventor.

As this is a pre-existing thread I am reluctant to move it so can I suggest you ask this question in the Inventor forum?

Thanks,

Jon

[Vish777]

Ok thanks!

I will give that a shot.