Error reading Gmsh mesh in FreeFem++

General Discussion
1

Hi !
I have an error reading a Gmesh mesh in Freefem++
#FreeFem++ script:

load “gmsh”
mesh Th = gmshload(“mesh.msh”);

#FreeFem++ output:
Element of type 5 is not considered in Freefem++

#Gmsh .geo script:

Point(1)={0,0,0,0.1};
Point(2)={1,0,0,0.1};
Point(3)={1,8,0,0.1};
Point(4)={0,8,0,0.1};

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

Curve Loop(1) ={1,2,3,4};

Surface(1) = {1};

Rotate {{0, 0, 1}, {0,0,0}, -Pi/3} {
Surface{1};
}
Mesh 2;

2

Element of type 5 is not considered in Freefem++ is 8-node hexahedron
and no hexahedron in freefem.

3

Thanks Frédéric !! It’s possible make a finite volume method on Freefem++ ??

4

Yes but to day is tricky.

5

Hi,

I am getting warning like this when i try to load mesh exported from Gmsh, Warning: – Your set of boundary condition is incompatible with the mesh label.
Warning: – Your set of boundary condition is incompatible with the mesh label.
Warning: – Your set of boundary condition is incompatible with the mesh label.
Warning: – Your set of boundary condition is incompatible with the mesh label.
Warning: – Your set of boundary condition is incompatible with the mesh label.

load “gmsh”

real Lx = 100.0 * d;
real Ly = 50.0 * d;

border b1(t=0, Lx/2) {x=t; y=d; label=1;}
border b2(t=d, 0) {x=Lx/2; y=t; label=2;}
border b3(t=Lx/2, Lx) {x=t; y=0; label=3;}
border b4(t=0, Ly) {x=Lx; y=t; label=4;}
border b5(t=Lx, 0) {x=t; y=Ly; label=5;}
border b6(t=Ly, 0) {x=0; y=t; label=6;}

mesh Th = gmshload(“mesh3011.msh”);

boundary condition…

  • on(1,3, u=0, v=0)
  • on(2, u=Uj, v=0)
  • on(4, u=-Uinf, v=0)
  • on(5, v=0)
  • on(6, p=0);

mesh3011.msh file looks like…

$MeshFormat
2.2 0 8
$EndMeshFormat
$PhysicalNames
6
1 1 “b1”
1 2 “b2”
1 3 “b3”
1 4 “b4”
1 5 “b5”
1 6 “b6”
$EndPhysicalNames
$Nodes
80782
1 0 0.0254 0
2 1.27 0.0254 0
3 1.27 0 0
4 3.81 0 0
5 3.81 1.27 0
6 0 1.27 0
7 0.009927406534577778 0.0254 0
8 0.01981601162725292 0.0254 0
9 0.0296659664128969 0.0254 0