[Gmsh] Meshing the area between an STL-merged object and surrounding box.

[Greg Retkowski]

Thanks for being so helpful! I'll give this a try when I get Delaunay
working under windows. The current windows binary blows up meshing with it.

-- Greg

Christophe Geuzaine wrote:
> Greg Retkowski wrote:
>> Hello,
>>   I'm trying to do some work with an STL-merged object and could use
>> some help.
>>
>> I have an STL model which I'd like to use for a CFD problem (via
>> OpenFlower). My plan is to create a box around the object, one end would
>> be the inlet, the other end the outlet, and the remaining sides of the
>> box would be boundary walls.
>>
>> I use 'merge' at the beginning of my gmsh file, and then set up a box
>> around my model. I set up the physical walls and volumes and then
>> attempt to mesh. The results are either that the STL object is meshed
>> (internal to the object) or no mesh is generated. I've tried lots of
>> different things in the geo file but cannot get it to mesh the area in
>> the box.
>>
>> The STL & Gmsh GEO file are available via these links...
>> http://www.rage.net/~greg/falcon1.stl
>> http://www.rage.net/~greg/falcon1.geo
>>
>> Any advice on getting the area between the STL object and the box
>> surrounding it would be greatly appreciated!
> 
> The attached file works with Gmsh 2.0 (use the 3D Delaunay algorithm in
> Options->Mesh->General).
> 
> However, note that Gmsh 2.0 does not remesh STL files, so the triangles
> in the STL are kept "as is" (which for your file leads to very poor
> quality tets). We plan to re-add STL remeshing in a future release.
> 
> CG
> 
> 
>>
>> Cheers,
>> -- Greg
>>
> 
> 
> 
> ------------------------------------------------------------------------
> 
> Merge 'falcon1.stl';
> 
> Point(201) = {-30.0,30.0,15.0,0.1};
> Point(202) = {-30.0,30.0,-15.0,0.1};
> Point(203) = {0.0,30.0,15.0,0.1};
> Point(204) = {0.0,30.0,-15.0,0.1};
> 
> Line(203) = {202,204};
> Line(204) = {204,203};
> Line(205) = {203,201};
> Line(206) = {201,202};
> Line Loop(207) = {203,204,205,206};
> Plane Surface(208) = {207};
> Extrude {0,-50,0} { Surface{208}; }
> 
> Surface Loop(1) = {1};
> Surface Loop(232) = {-217,208,-221,-225,-229,-230};
> Volume(233) = {232,1};


-- 
Greg Retkowski / http://www.linkedin.com/in/gregretkowski | RAGE
greg at rage.net  http://www.rage.net/~greg/ C:408-455-3913  | .NET