Learning Forum

[Archoncommando]

Hello there people!

I'm having some issues getting the options of my mesh generation right. I'm working on a bachelor's thesis using Ansys 19.2. It's based off of a previous work using 16.2.

Professor wants me to retrace the steps for mesh generation down to most options to get a comparable result to the old wing design.

Now the problem is that between 16.2 and 19.2 it seems a lot of options changed in the mesh options.

For example the parameters i see in the old work include:

Size function = curvature
Transition = slow
spanangle? (It's all in german and i don't really know how to correctly translate this one) = fine
min. size = 1
min tetrahedron size = 1

But in 19.2 size function seems to be gone. I saw a different thread talk about adaptive sizing but nowhere did it talk about "curvature". However in 19.2 there is an option called "regard (?) curvature" that i set to yes. It won't give me options to set minimum sizes however.

These issues continue once i try to set up influence bodies. In 16.2 you can select size function curvature but i don't see any option like that for influence bodies in 19.2. It shows up when selecting components instead of bodies when using the element size options in meshing control.

Are there any good ressources on how these sort of options translate to 19.2? If anyone knows how i could install 16.2 in the first place that would also be greatly appreciated but i can't find any downloads for it.

 

Thanks in advance!

[peteroznewman]

Relevant discussion.

[raul.raghav]

In Ansys 19.1 or newer, the options for Size Function, Relevance, Relevance Center, Max Face Size, and Max Tet Size have been removed.

When using Ansys 19.1 or newer, the following applies:

• Under Sizing:


• Use Adaptive Sizing -> Yes,


• Resolution -> 0 (coarse) to 7 (fine); Default value is 4 for Electromagnetics or Explicit, and 2 for other solvers.


• Under Defaults:


• Element Size = Max Face Size (in Ansys 19.0 and earlier versions)

 

• Under Sizing:


• Use Adaptive Sizing -> No, activates two other options: Capture Curvature (Yes/No) and Capture Proximity (Yes/No). If both are No, then its equivalent to "Uniform".


• Resolution -> 0 (coarse) to 7 (fine); Default value is 4 for Electromagnetics or Explicit, and 2 for other solvers.


• Under Defaults:


• Element Size = Max Face Size (in Ansys 19.0 and earlier versions)


• Max Size = Max Tet Size (in Ansys 19.0 and earlier versions)

[Hafiz]

Hi Rahul! 

As you mentioned that Element Size = Max Face Size (in Ansys 19.0 and earlier versions), here the scale of Element size is length, e.g "mm", whereas Face size represents length^2 scale. How they could be the same?

Please resolve this confusion.

I thought Element Size is the (max or min (not sure)) size of the edge. Isn't?

[Rob]

Mesh something simple and see what happens, it's also covered in the documentation (click Help to access). The units make sense most of the time once you understand what's being applied where. 

[Hafiz]

According to the ANSYS manual, "Element Size is calculated as Bounding Box Diagonal * Bounding Box Factor. where Bounding Box Diagonal is the length of the diagonal and the Bounding Box Factor is set to a default value of 0.05."

Whereas, for local sizing control, For a face selection, "Element Size is the maximum size on the face, which is then propagated down to the edges."

I got confused. Could you please explain them?

[Rob]

Mesh a simple shape and see what happens. 

[LeonBrown]

Please where can i find meshing documentation? i cannot see the Help icon to click on. Thanks in advance.n

[peteroznewman]

nUse the Windows Start menu. In the ANSYS folder is ANSYS Help.n

[LeonBrown]

Thank you very much.n