[daonguyen177]

Hi all,
I am trying to create meshes in Gmsh version 3.0.6 and import them to openFoam 6. I have a problem when using periodic in Gmsh. Here is the code:
Circle(1) = {0, 0, 15, 150, -Pi/12, Pi/12};
Circle(2) = {0, 0, 15, 80, -Pi/12, Pi/12};
Line(3) = {3, 1};
Line(4) = {4, 2};
Line Loop(1) = {2, 4, -1, -3};
Plane Surface(1) = {1};
//+
Extrude {0, 0, -10} {
Surface{1};
}
Physical Surface("inlet") = {4};
Physical Surface("outlet") = {2};
Physical Surface("walldown") = {6};
Physical Surface("wallup") = {1};
Physical Surface("side1") = {5};
Physical Surface("side2") = {3};
Physical Volume("waterflow") = {1};

Transfinite Line {3, 12, 4, 9} = 41 Using Progression 1;
Transfinite Line {2, 7, 1, 11} = 31 Using Progression 1;
Transfinite Line {5, 10, 8, 6} = 21 Using Bump 0.5;
Transfinite Surface "*";
Transfinite Volume "*";
Recombine Surface "*";

Periodic Surface {3} = {5} Rotate {{0, 0, 1}, {0, 0, 0}, -2*Pi/12};

I tried to use periodic surface for side1 and side2 but it didn't work! I also tried to use Gmsh version 4.5.4 or tried to create surface side 2 by using extrude rotate side1 but error still occurred. Any ideas for my problem? Also, any suggestion for free software for creating periodic cases! Many thanks!