[Gmsh] periodic mesh

[Christophe Geuzaine]

> On 02 Feb 2016, at 20:59, Josefin Ahlkrona <josefin.ahlkrona at it.uu.se> wrote:
> 
> Hi,
> 
> I have a cuboid (x,y,z) domain for which i have created tetrahedral, structured mesh.  Now, I want to apply periodic boundary conditions in x, and y direction and in order to do that I need the mesh to be identical for the x=0 and x=xmax surfaces, as well as for the y=0 and y=ymax surfaces. It is not sufficient for only the nodes to match but I also want the edges to match!
> 
> I have tried to use the "Periodic Surface" command without success. I have seen several posts on using the "Periodic Surface" commands without finding a solution for my problem.
> 

The Periodic meshing command only apply to unstructured grids. In your case the grid is set structured (meshed by extrusion with the "Layers" option).


> Could anyone help me?
> 
> My geofile looks like this:
> 
> cl=1.0;
> //cuboid which is 8000,8000,1000 big
> 
> Point(1) = {0,0,0,cl};
> Extrude {8000,0,0} {
>  Point{1}; Layers{10};
> }
> Extrude {0,8000,0} {
>  Line{1}; Layers{10};
> }
> Extrude {0,0,1000} {
>  Surface{5}; Layers{5};
> }
> 
> 
> boundMaster[] = Boundary{26};
> boundSlave[] = Boundary{-8}; //tried plus and minus sign here..
> boundMaster2[] = Boundary{22};
> boundSlave2[] = Boundary{-14};  //tried plus and minus sign here..
> 
> Periodic Surface 18 {boundSlave[]} = 26 {boundMaster[]};
> Periodic Surface 14 {boundSlave2[]} = 22 {boundMaster2[]};
> 
> Physical Surface(28) = {14};   //y=y0
> Physical Surface(29) = {18};   //x=xmax
> Physical Surface(30) = {22};   //y=ymax
> Physical Surface(31) = {26};   //x=x0
> Physical Surface(32) = {5};    //top
> Physical Surface(33) = {27};   //bottom
> 
> Physical Volume(34) = {1};
> 
> Best,
> 
> Josefin
> 
> 
> _______________________________________________
> gmsh mailing list
> gmsh at onelab.info
> http://onelab.info/mailman/listinfo/gmsh

-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine

Tetrahedron V, July 4-5 2016: http://tetrahedron.montefiore.ulg.ac.be
Free software: http://gmsh.info | http://getdp.info | http://onelab.info