[BrendaEM]

Because .stp files are the defacto standard for surface definition, it would be a great advantage if OpenFoam could convert .Step brep surfaces directly from separate files to each represent boundaries in a simulation.

Snappy Hex Step would test to see if the result is manifold and airtight.

The name of the step file becomes the boundary name that are used in the preprocessor files.

There would be great advantages to doing this:
1.) We don't have to needlessly create an intermediate mesh.
2.) We have smaller file and project sizes because there are less intermediate files.
3.) Most 3D design and CAD programs, both closed as well as open sourced can use .stp.
4.) Because we aren't reinterpreting a mesh, accuracy may be better than the methods that are in use.
5.) In a landscape of few open front-ends, OpenFoam will become more accessible than it is now.
6.) Problems with source mesh integrity will not exits.
7.) Users and researchers may better focus on the research, with less attention needed to workflow and process.
8.) People will have fewer problems to ask for help with in these forums.

For instance, the user would save out:L
car.stp
road.stp
outlet.stp
walls.step

And then set up the initial conditions, and run SnappyHexStep, and then run OpenFoam to solve.

Thanks for your consideration,
Brenda Ellen Make

[wyldckat]

Quick notes: Following up on old posts of yours, because I was looking for the one about non-orthogonal meshes, I noticed this one and I moved it to the snappyHexMesh sub-forum.

The notes I want to leave here are as follows:

1. STEP format is not perfect either, even though it's a fairly good 3D CAD format. See this blog post for a bit more information about the limitations with existing 3D CAD formats: https://blog.pointwise.com/2017/12/2...-in-beta-test/
2. OpenCascade is essentially an opensource toolbox that provides the ability to interpret STEP files. FreeCAD, Salome and pythonOCC use it. In principle, OpenFOAM would also have to rely on it.
3. The critical limitation is effectively funding. Given the existing two major avenues of official development on OpenFOAM:
   1. Knocking on OpenFOAM Foundation's door means that you should also be willing to help fund this somehow. We all have wishes, but someone has to foot the bill...
   2. Knocking on ESI-OpenCFD's door may help them decide to look into possible supporters for this feature. Sometimes it's just a matter of being reminded that "oh, this is a thing we could do? I wonder if XYZ would be interested in sponsoring this..."
   3. That said, who knows if the people working for the OpenFOAM Foundation saw your feature request, their supporters would be willing to support this request?

Either way, the contact avenues to give this a bit more signal boost exist:

• The issue tracker at the OpenFOAM Foundation: https://bugs.openfoam.org
• The issue tracker at ESI-OpenCFD: https://develop.openfoam.com/