[jam]

Is it possible to simulate this problem?
I have looked in the forum and the closest I found was a 3d cube but with two faces parallel to the outside boudary and touching it.
-Alain

[olwi]

Hi Alain,

In principle, your case is different only in geometry. You need a grid-generator for making your mesh, though. It's too complicated for blockMesh.

The problem may be large, however, if you want to resolve transient features and finer details of the flow. But that's another story...

/Ola

[jam]

Thanks Ola,
I have no problem generating the mesh with Gmsh. I have to define the outside box with boundary condition like inlet and outlet and wall. For the inside cube which boundary condition can I define? With gmshToFoam, I get no patches available for anything inside that big box.

I have the following messages :
.
.Finding faces of patch 10
--> FOAM Warning : Not using gmsh face 3(11 188 13) since zero vertex is not on boundary of polyMesh
.
.



-Alain

[olwi]

Sorry to state the obvious: The bc on the cube walls should be "wall".

Not so sure how to deal with the Gmsh mesh, though. What you are looking for is an empty hole for the cube in the middle of your mesh. If that is not what you have, let's hope an expert user of Gmsh reads this thread and comes to your rescue... Thing is that boundaries in OF have cells only on one side, i.e. they must be exteriour faces (="on boundary of polyMesh", see your warning message).

If you *do* have a whole in the middle, then there should be tools to pick up those faces (e.g. using the faceSet utility), and then create a wall patch for them (with some other utility). There are plenty of nifty utilities, the trick is just to know of their existens and understand how they work...

/Ola

[jam]

I have downloaded a 3d case from somewhere in this forum ( 3d_tar-1985.tgz) . In that case, two faces of the cube are touching the chamber walls.What I want to know is if it is possible to have a cube completely inside the chamber?

-Alain

[jam]

Good news. I have a solution for a cube completely inside the chamber.I am using the sonicTurboFoam solver with the prism case. I have to look carrefully at how I got it, starting from Gmsh and producing a mesh and then using gmshToFoam to generate a mesh to be used in the solution.

-Alain