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-   -   Surface triangle mesh with strict constraint (http://www.cfd-online.com/Forums/main/107720-surface-triangle-mesh-strict-constraint.html)

 arnom October 4, 2012 13:56

Surface triangle mesh with strict constraint

Dear all,

as I'm from the meshfree community my skills in meshing are practically non-existent. However, I have the following problem at hand which I can't seem to be able to find a solution for.

Let's assume I have a general shell geometry and I would want a surface mesh of this shell. First of all, I can only use triangles and secondly I want to impose a limit on the edge length of the triangles.

Now, I tried Icem, gmsh and Salome and although they let me impose a limit, it is not strictly enforced. That means that if I set my max edge length = 0.1, there would always be edges with length > 0.1. Unfortunately that renders the meshing useless as I really need strict enforcement of this constraint. Thus my simple question, is there a meshing software that can achieve this?

Bonus question: The actual constraint that I have is the distance from the triangles barycentre to the vertices. Again, I'd need strict enforcement but I guess there is no meshing software that actually even has such a constraint or am I wrong?

Arno

 julien.decharentenay October 4, 2012 18:56

Hi Arno,

I do not know of a meshing software that would fit your requirements. But how hard is it to subdivide a triangle to meet the distance requirements?

Julien

 arnom October 5, 2012 03:34

Hi Julien,

thanks for your reply. Well obviously it's not hard to just split a triangle into two. But for computational reasons I'd like to have as less triangles as possible. As you might now meshfree methods are already slow, so I'd like to avoid every additional load if I can.

Cheers,
Arno

 ogloth October 5, 2012 04:47

Hi Arno,

we develop an open-source tool called enGrid which has its own surface mesher. Although the feature you require is not there, it would probably not be too difficult to implement it. If you want to try, I could point you in the right direction. Or, alternatively, if you have a small budget we could implement it for you.

One (current) requirement of enGrid, however, could be a show-stopper: As geometry you need to provide a water-tight STL geometry (or similar) -- you cannot import CAD geometries directly.

Cheers,
Oliver

 arnom October 5, 2012 04:57

Hi Oliver,

I'm a PhD student, so funds for these kinds of things are not available unfortunately. Also, I probably won't have time to work on it during my day to day work, so it'd be a free time project. I'll send you a pm with my email so that we can discuss further things in private without spamming around here.

The STL requirement is not a problem for me. From your website I see that I could use STEP or IGES which is pretty much all I need.

Cheers,
Arno

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