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-   -   Hex with transfinite Volume (https://www.cfd-online.com/Forums/openfoam-meshing-open/72369-hex-transfinite-volume.html)

 Mjoelnir February 3, 2010 11:00

Hex with transfinite Volume

Hi everybody,

i'm trying to mesh a section of sphere.

Code:

``` // Convert to meters toM=1; // Characteristic length lc = 1*toM; //Height and radius //Aspect ratio Teta=D/h D=0.29; R=D*0.5*toM; h=R*toM; r=R/1.5*toM; w=R*0.5; W=R*0.6;   Ru=Sqrt(R*R-W*W); Point(1) = {0,0,0,lc}; Point(2) = {R,0,0,lc}; Point(3) = {0,R,0,lc}; Point(5) = {r,0,0,lc}; Point(4) = {0,r,0,lc}; Point(6) = {Ru,0,-W,lc}; Point(7) = {0,Ru,-W,lc}; Point(8) = {r,0,-w,lc}; Point(9) = {0,r,-w,lc};   Circle (1) = {2,1,3}; Line (2) = {3,4}; Line (3) = {4,5}; Line (4) = {5,2}; Circle (5) = {2,1,6}; Circle (6) = {3,1,7}; Line (7) = {4,9}; Line (8) = {5,8}; Circle (9) = {6,1,7}; Line (10) = {7,9}; Line (11) = {9,8}; Line (12) = {8,6};   nodes1=11; nodes2=5; Transfinite Line {1,3,5,6,7,8,9,10,11} =nodes1; Transfinite Line {2,4,10,12} =nodes2; Line Loop (1) ={1,2,3,4}; Plane Surface (1)={1}; Line Loop (2) ={5,9,-6,-1}; Ruled Surface (2)={2}; Line Loop (3) ={6,10,-7,-2}; Plane Surface (3)={3}; Line Loop (4) ={7,11,-8,-3}; Plane Surface (4)={4}; Line Loop (5) ={8,12,-5,-4}; Plane Surface (5)={5}; Line Loop (6) ={9,10,11,12}; Plane Surface (6)={6}; Transfinite Surface {1} = {2,3,4,5}; Transfinite Surface {2} = {2,3,6,7}; Transfinite Surface {3} = {3,7,9,4}; Transfinite Surface {4} = {4,5,8,9}; Transfinite Surface {5} = {2,5,6,8}; Transfinite Surface {6} = {6,7,8,9}; Recombine Surface {1,2,3,4,5,6};   Surface Loop (1) = {1,2,3,4,5,-6} ; Volume (1) = {1};     Transfinite Volume {1} = {2,3,4,5,6,7,8,9};     //Physical Surface("Wall") = {2,3,4,5,37,54,59,76,81,102,103,120,125} ;   //Physical Volume ("internalField") = {1};```

i get following error Message:

Error : Incompatible surface 3 in transfinite volume 1
Error : Cannot tetrahedralize volume with quadrangles on boundary

i've no idea what could cause this problems

Thanks you

 ericnutsch February 4, 2010 01:59

The error message sounds fairly intuitive; Squares and triangles don't mix on surfaces, but hard to say without seeing it.

If you have tets' you may want to move their definitions to end of the script and put the hexes' at the beginning(long shot, but its worth a try) I will need some print screens of your problem to be of any further help.

You can attach photos with the "mange attachments" button below.

Best of Luck!

 Mjoelnir February 9, 2010 12:54

Pictures

4 Attachment(s)
If i don't use the command Recombine Surface, i can build a 3d Mesh

Without this command i can't create an 3d Mesh.

thanks

Mjoelnir

 Mjoelnir February 17, 2010 11:55

Problem solved

i figured out the Problem. in the transfinite Volume command the order of the points ist important.

 robingilbert April 1, 2010 19:00

hi i have a similar problem!!
what order of points are we supposed to use??
thank you

 Mjoelnir April 8, 2010 08:29

its like in Blockmesh

http://www.openfoam.com/docs/user/me...23-1270005.1.1

for hexandron

 robingilbert April 8, 2010 13:52

oh ya!!! thanks a lot..
thank you so much for the help!!

 menonshyam May 12, 2014 18:00

Incompatible surface in transfinite volume

Hello, I am getting a very similar error and was wondering if you could spot what is wrong in the numbering of the volume! The error i get is "Incompatible surface 22 in transfinite volume 28". Here is my code:

lc = 0.005;

Point(1) = {0,0,0,lc};
Point(2) = {length,length,-length,lc};
Point(3) = {-length,length,-length,lc};
Point(4) = {-length,-length,-length,lc};
Point(5) = {length,-length,-length,lc};

Circle(6) = {3,1,2};
Circle(7) = {2,1,5};
Circle(8) = {5,1,4};
Circle(9) = {4,1,3};

Line(13) = {4, 1};
Line(14) = {5, 1};
Line(15) = {2, 1};
Line(16) = {3, 1};

Line Loop(17) = {13, -16, -9};
Ruled Surface(18) = {17};
Line Loop(19) = {16, -15, -6};
Ruled Surface(20) = {19};
Line Loop(21) = {15, -14, -7};
Ruled Surface(22) = {21};
Line Loop(23) = {14, -13, -8};
Ruled Surface(24) = {23};
Line Loop(25) = {8, 9, 6, 7};
Ruled Surface(26) = {25};
Surface Loop(27) = {18, 22, 26, 24, 20};
Volume(28) = {27};
Transfinite Line {13, 14, 15, 16} = 10 Using Progression 1;

Woutlet = 26;
Wfront = 18;
Wback = 22;
Wtop = 20;
Wbottom = 24;
WinternalVol = 28;

Physical Volume("internalVol") = {WinternalVol};
Physical Surface("outlet") = {Woutlet};
Physical Surface("front") = {Wfront};
Physical Surface("back") = {Wback};
Physical Surface("top") = {Wtop};
Physical Surface("bottom") = {Wbottom};

Transfinite Surface "*";
Recombine Surface "*";
Transfinite Volume "*";

Thanks!

 Bharath Bhushan March 30, 2017 08:52

3D mesh in gmsh

Hello guys,

I have a problem. I need to mesh the imported geometry. The thing is I cant change the geometry nor I can insert anything. All I can do is transfinite the line, surface and recombine it. But to get correct 3D mesh I need to transfinite the volume. I cant create the volume and also transfinite the volume selecting the ordered points.

is there any other way of transfinite the volume without selecting the points ?

thank you

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