[Gmsh] High-Order Meshing

[Rene Schneider]

On 12/11/2013 11:53 AM, George Ntemos wrote:
> Dear Gmsh Development Team,
>
>
> My name is George Ntemos and I am a PhD student in the Aeronautics
> Department of Imperial College London. Our team is developing and
> applying CFD software, using gmsh for high-order meshing purposes.
>
> I am currently studying a flow case around a rod-aerofoil set-up and
> I've been experiencing some problems with high-order meshing. More
> specifically, the meshing algorithm fails to mesh in high order around
> the (spline-defined) aerofoil profile. Please find attached a
> lightweight .geo file of my configuration just for demonstration
> purposes. If one tries meshing this file in 3d and for order > 1, gmsh
> will warn that, to my understanding, the algorithm fails to properly
> converge at certain points, visibly resulting in quite severe
> discrepancies for a few elements (curvilinear on). It also warns that it
> cannot orient the normal for the two extruded surfaces of the rod
> (cylinder) boundary layer. It is worth noting here that I am
> experiencing none of the above problems when I am meshing in 2d. Since
> my 3d mesh is just a simple extrusion, I would assume that extending to
> 3d is just a trivial case of translating every operation along the 3^rd
> dimension. I am of course not particularly experienced in using gmsh
> however and I may very well be missing something here.

Hi George,

this reminds me of a bug upon which I stumbled myself. Sebastian Eiser 
then pointed me to the bug report:
   https://geuz.org/trac/gmsh/ticket/184 (gmsh:gmsh)

As far as I know, this is still not fixed.

If you observe this with the latest svn version, you can add your 
example to the bug report, to give it more weight.

Rene


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       Dr. Rene Schneider

       TU Chemnitz, Fakultaet fuer Mathematik,
       09107 Chemnitz, Germany

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       http://www.tu-chemnitz.de/~rens

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