[SU2User1234]

I've been experimenting with SU2 recently trying to get a better grasp on it and the math involved. I created a .su2 file based on an stl file and things appear to be going alright except that I get a negative drag after running the SU2_CFD program. I don't know if it's related, but the program also finishes in less than a second and goes through very few iterations whereas the tutorials take plenty of time to complete. Is there something wrong with the generated su2 file or the settings being used? I've zipped all of the relevant files and the results. They should be attached. Any help or advice would be greatly appreciated.

[ceanwang]

I am just thinking to created a .su2 file from a stl file. In which way you did that?

It seems you only have a ball, you need to put the ball inside a space, so fluid can flow around that ball.

[pcg]

Hi,

Cean is correct. Referring to your mesh file, it specifies a 3D problem (NDIME=3) but the elements that follow are triangles (VTK type 5). You need to generate a volume mesh, if you are looking to do this yourself the following page describes the SU2 mesh format very well and has some examples: https://su2code.github.io/docs/Mesh-File/

Regards,
Pedro

[SU2User1234]

Originally Posted by ceanwang

I am just thinking to created a .su2 file from a stl file. In which way you did that?

It seems you only have a ball, you need to put the ball inside a space, so fluid can flow around that ball.

I think gmsh is supposed to be able to but I couldn't get it to work so I wrote my own quick program to parse ascii stl and throw out an su2 file. Obviously it's not quite right yet though . When you say put it in a space, do you mean like placing the sphere in a large box?

Originally Posted by pcg

Hi,

Cean is correct. Referring to your mesh file, it specifies a 3D problem (NDIME=3) but the elements that follow are triangles (VTK type 5). You need to generate a volume mesh, if you are looking to do this yourself the following page describes the SU2 mesh format very well and has some examples: https://su2code.github.io/docs/Mesh-File/

Regards,
Pedro

Thanks for the information. I assumed that using something like a pyramid would be no different than building it manually with triangles, but I guess this assumption is wrong? If so, what kind of base shape would I use to create the sphere-like object I need?

[ceanwang]

yes, use that big box as a wind tunnel.

[SU2User1234]

That makes sense. I've been messing around with adding the box around it but I get a variety of errors depending on what I do. If I just add 6 squares around it, I get a divergence error because of a NAN occurring somewhere. I figure this has to do with my lack of 3d shapes? When I try to switch either the box to a prism or the triangles to tetrahedral shapes (where I make the 4th point either on the plane creating essentially a triangle, or make it in a random otherwise unused place), I get a segfault shortly after it starts. I am at a loss for what is going wrong with the shape. Any ideas?