CFD Online Discussion Forums - Create an internal face

Hi to All,

I simulate a flow in a channel.

-fluid: water
-transport model: Newtonian
-very small velocity at inlet face that results in a laminar flow in the whole channel

The channel has a length of 3,1m (x-direction, width = y-direction = 0,250m, height = z-direction = 0,02m).

Attempt 1

I would like to define an internal face in the blockMeshDict to be able to map the final velocity field of that internal face on the inlet face of another channel model as boundary condition with help of mapFields utility.

The channel consists of three blocks. The desired internal face connects block 1 (

x = 0m - 1m = 1m) with block 2 (

x = 1m - 2,5m = 1,5m).

If I add two additional patches (outlet_block1, inlet_block2) in the boundary () subdictionary and list them up in subdict mergePatchPairs () I get an error message after starting blockMesh.

Quote:

--> FOAM FATAL ERROR:
Trying to specify a boundary face 4(0 3 7 4) on the face on cell 0 which is either an internal face or already belongs to some other patch. This is face 0 of patch 5 named Developing_outlet.

From function polyMesh::setTopology
(
const cellShapeList& cellsAsShapes,
const faceListList& boundaryFaces,
const wordList& boundaryPatchNames,
labelList& patchSizes,
labelList& patchStarts,
label& defaultPatchStart,
label& nFaces,
cellList& cells
)
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 360.

FOAM aborting

Attempt 2

I've created the velocity field of that internal face with sample utility --> folder surfaces is created and contains for each time step the required data. But then I am not able to map that data on the inlet boundary of the other model with help of mapFields.

MapFields maps the complete volume velocity field from model 1 to model 2. But I would like to map only the velocity field of the internal surface to the inlet surface (inlet boundary condition) of model 2.

Can anybody help???

Aylalisa