CFD Online Discussion Forums - Immersed Boundary Method: problems with .stl file

Dear all,

I am working on my master thesis project but it's been a few days that I am frighteningly stuck on a dead point. So I am asking here for help.

I am trying to set up my own Immersed Boundary Method (IBM) problem starting from the tutorials that are present in the foam-extend4.1. In particular, I am referring to the movingCylinderInChannelIco one.
Using the test case, everything works properly but the problems start when I replace the already prepared .stl file with one that I have generated myself, even though it is a very dumb one: a parallelepiped divided in only 12 triangles.

Being more precise, the error that I receive, while executing the potentialFoam command, is the following:

Quote:

--> FOAM FATAL ERROR:
Error in point ordering: mixed used and unused points at the end of point list.
Last used point: 0 (-100 -100 -100)
First unused point: 1 (-96 -100 -100)
and point 1 (-96 -100 -100) is used by a live face.
Face 0 4(1 77 2053 1977) with points 4((-96 -100 -100) (-96 -92 -100) (-96 -92 -88) (-96 -100 -88))
Done.

From function void polyMesh::initMesh()
in file meshes/polyMesh/polyMeshInitMesh.C at line 166.

FOAM aborting

Aborted (core dumped)

I have a suspect on which one is the nature of the problem but I have no clue on how to fix it.
In fact the tutorial gives few lines, in the directory "save/boundary", that need to be copy-pasted in order to include the .stl file into the previously generated blockMesh. I think that, building my own .stl file, I should modify the following lines but I am not able to figure how to do it.

Quote:

ibCylinder
{
type immersedBoundary;
nFaces 0;
startFace 3650;

internalFlow no;
isWall yes;
}

In particular, I am pretty sure that the value for the startFace is wrong but I don't know how to extract the correct one from an .stl file.

For the sake of completeness, I remark the fact that I am working with the foam extend, therefore I cannot use the topoSet command.

Is there anyone that know how to do it properly? Or how to get rid of this problem?

I am available for further clarifications.

Many thanks in advance. :)

Enrin