[acahuzac]

Hello,

I am trying to simulate a Savonius turbine in 2D with OpenFoam. I need it to rotate and thought about using the "cyclicAMI" BC.

I created my mesh using Gmsh. The geo file is enclosed : "profile2D.geo". The mesh generates correctly.

My problem arises when i try to gmshTofoam it.

Starting to read mesh format at line 2
Read format version 2.2  ascii 0

Starting to read physical names at line 5
Physical names:8
    Surface 1   Sides
    Surface 2   Inlet
    Surface 3   Outlet
    Surface 4   Walls
    Surface 5   InterInt
    Surface 6   InterExt
    Volume 7    InterInt
    Volume 8    InterExt

Starting to read points at line 16
Vertices to be read:252182
Vertices read:252182

Starting to read cells at line 252201
Cells to be read:745608

Mapping region 1 to Foam patch 0
Mapping region 5 to Foam patch 1
Mapping region 4 to Foam patch 2
Mapping region 3 to Foam patch 3
Mapping region 2 to Foam patch 4
Mapping region 6 to Foam patch 5
Mapping region 7 to Foam cellZone 0
Mapping region 8 to Foam cellZone 1
Cells:
    total:248000
    hex  :0
    prism:248000
    pyr  :0
    tet  :0

CellZones:
Zone    Size
    0   99334
    1   148666

Skipping tag  at line 997812
Patch 0 gets name Sides
Patch 1 gets name InterInt
Patch 2 gets name Walls
Patch 3 gets name Outlet
Patch 4 gets name Inlet
Patch 5 gets name InterExt
--> FOAM Warning :
    From function polyMesh::polyMesh(... construct from shapes...)
    in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 627
    Found 499498 undefined faces in mesh; adding to default patch.
Finding faces of patch 0
Finding faces of patch 1
--> FOAM Warning :
    From function gmshToFoam
    in file gmshToFoam.C at line 972
    Could not match gmsh face 4(16 1830 3268 33) to any of the interior or exterior faces that share the same 0th point

The first warning is normal : it affects all the faces with no physical name to default patch. But then, there are a bunch of :

--> FOAM Warning :
From function gmshToFoam
in file gmshToFoam.C at line 972
Could not match gmsh face 4(16 1830 3268 33) to any of the interior or exterior faces that share the same 0th point

and in the end, the boundary file sets an nFace=0 to all subsequent boundaries.

I first tried to put

Geometry.AutoCoherence = 0;

in my .geo file to avoid coincident surfaces to be merged by gmsh.

Then I tried to define the two surfaces in contact with a different number of point through "transfinite".

I found a post about an error to gmshTofoam (http://www.cfd-online.com/Forums/ope...eset-gmsh.html) but the solution give there did not work either.

Pbms similar to mine :
http://www.cfd-online.com/Forums/ope...mshtofoam.html
http://www.cfd-online.com/Forums/ope...mshtofoam.html

thanks for the help !

[acahuzac]

Ho, I forgot to mention the "epsilon" parameter used to separate the two cylinders. Using it or not yields the same problem.

[acahuzac]

Solved :

I had to make two distinct mesh, and then merge them with "mergeMeshes".