Meshing thin, curved solids in Gmsh
 

I've encountered a problem for a design I'm trying to mesh with Gmsh. Basically, the issue is in a solid that looks like a hollow cone; the wall cone is very thin (the thickness of the wall is 0.1, while the top diameter of the cone is 10, and the bottom is 6; height is 14). The issue seems to be with the 2D meshing of the outer and inner cone surfaces: some of the triangles from the outer surface intersect some triangles on the inner surface.

This design is supposed to be simulated a lot of times with slight variations, so I'd like to get a small mesh that's amenable to quick simulations. In my experiments so far a mesh of about 100K elements with a meshing time of 45s is good.

I can change Mesh.MinimumCirclePoints in the .geo file, but if I set it high enough to avoid the issue, meshing takes 4 minutes and results in 800k mesh elements. I can also change the characteristic length (either for the entire design or just a box around this solid), but the result is again a large mesh and very slow meshing.

Is there a way to avoid the issue of intersecting triangles while avoid a big penalty in speed/size?

Thanks.
Tibi