[francois]

Hi all,

I've just started to do one simple mesh which contains a solid volume (solid wall) which will be heated inside the computational domain. But I have some problem here figuring how to do this.

To illustrate what I want to achieve I made a picture of a square solid with a square hole in it. This solid volume is inside the computational domain. My configuration is more complex but let's start with an easy one.



The meshing part with blockmesh is easy for me: I have defined the verticies, edges and the different blocks.

But after, how do I define the solid volume with the hole as a wall to impose an heat flux or a temperature on it ?

I already search on the UserGuide, Wiki and Forum with no success. If you have some suggestions which can help me...

thank you very much.
Best regards
Francois

[juanduque]

Have you defined patches? Patches are composed by the boundary faces (See Cavity example blockMeshdict, where they define sets of block faces as different patches, E.G fixedWalls, movingWall, etc...). The Block faces you define must comply with the right hand rule and MUST belong to a block.

After you define patches, you can set the proper boundary conditions (for each field) for using with the solver you've chosen.

Hope that helps,

[santos]

Hello Francois,

I would recommend you the new meshing utility introduced in OpenFOAM 1.5: snappyHeshMesh. Read its section in the User Guide for indications on how to use it.

You could export your solid volume with the hole as a STL file, using eg. Salome, then snappyHeshMesh would take care of the rest.

Regards,
Jose Santos

[francois]

Thanks Juan and Jose !
It's nice from you ...

Jose: Your solution looks very good but I prefer to stay with blockmesh at present time because I have some python scripts which build my blockmesh dict file. Thanks for the advice be sure I will look at your solution when I will have enough time.

Juan: indeed some patches must be defined and my question was how to define those patches in 3D for a solid volume with a hole. I want to do some simulation with coupled heat transfer (take the conduction into account in the solid volume) but don't know where to start or look for.

So if I understand you correctly, I must define a patch (call it square_hole) with all the faces which surround the solid volume. That's all ? After that how can I specify which inner cells belong to the solid volume and which cells are in the fluid region ?

Hope I'm clear and you can understand me.
Anyway thanks for your help and if you have more advices ... they will make me happy !

Thanks again
Regards
francois

[juanduque]

Francois:

As I understand your square-donut is the CFD domain you're trying to analyze. The walls that bound it are the interphase with a solid, am I right?

Yes, to define a patch you must use the faces that define the blocks of your blockmesh (remember, right hand rule is to be applied).

Which solver are you using for the coupled heat transfer problem?

Good luck!

[francois]

Hi Juan,

Not exactly: the square-donut in gray in the solid volume and the cube around it, the fluid region.

I just tried to define a patch with all the faces which surround the solid volume in gray and I'm in trouble here because the faces which are selected are internal faces. See error message below after blockMesh:

Trying to specify a boundary face 4(16 17 21 20) on the face on cell 8 which is either an internal face or already belongs to some other patch.

Don't know what can be done to define such patch/region ??

For the solver I will use for the coupled heat transfer, I saw some posts here on the forum on such a solver perhaps on sourceforge. Don't konow if it's available in OpenFOAM 1.5

[juanduque]

can you post your blockMeshDict?

[francois]

Yes of course
The blockMeshDict I'm working on is with a different geometry: cylindric plate with a hole inside a cylinder. But the problem is the same one.

See picture below



The blockMeshDict is just here:

blockMeshDict