# [Gmsh] Making structured meshes

Christophe Geuzaine cgeuzaine at ulg.ac.be
Fri Dec 14 10:23:49 CET 2007

```SJ Lai wrote:
> Hi Christophe,
>
> I'm currently experimenting with gmsh trying to create a mesh around a
> 2D trailing edge corrugated aerofoil profile. Attached is a simple one
> that I had attempted, and I was wondering if there was a way to create a
> structured mesh with more than 4 points. (Say if Line (3) was taken out,
> would it still be possible to make a structured mesh?) I've tried a few
> times using different ways, but have yet to succeed.

Hi Jake - Yes, you can specify the four corners of the transfinite
interpolation across multiple lines (this will only work if the geometry
is "regular enough" and without holes).

For example, if you remove line 3:

Geometry.OldNewReg=0;

lc=100;

Point (1)={0,0,0,1};
Point (2)={0,10,0,lc};
Point (3)={15,10,0,lc};
Point (4)={15,7,0,lc};

Point (5)={15,0,0,lc};
Point (6)={15.001,-7,0,1};
Point (7)={15.001,-10,0,1};

Point (9)={0,-10,0,lc};

Point (10)={20,0,0,lc};

Line (1)={1,2};
Line (2)={2,3};
//Line (3)={3,4};
Line (4)={4,1};

Spline(5)={4,10,6};
Circle(6)={3,5,7};
Line (7)={6,7};

Line(10)={1,9};
Line(11)={9,7};
Line(13)={6,1};

Line Loop(1) = {6,-7,-5,4,1,2};
Plane Surface(1) = {1};

Transfinite Line {1,7}=80 Using Progression 1.2;
Transfinite Line {2,4,5,6}=50;
Transfinite Surface{1} = {1,6,7,2};
Recombine Surface{1};
Mesh.Smoothing = 100;

>
> Also, using separate method also gives me discontinuities at the block
> boundaries which is unfavorable. Anyway to overcome that as well?
>
> As the corrugations that I will be using are sharp, that'll mean i'll
> have to make 20 blocks on each surface to get a structured profile.
>
> Thank you so much, and Merry Christmas.
>
> Jake
>
> _______________________________________________
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> http://www.geuz.org/mailman/listinfo/gmsh
>
>

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

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