[wista59]

I am new user and am trying on heat transfer in Fluent .I have three domain (fluid-solid-fluid).I want to make Conjugate heat transfer here . I cant see a -shadow boundary condition of type wall for each interface wall .And I dont open coupled in thermal conditions.I am adding my system project pictures and files.







Now , What I must do ?

For system drawing file download : https://hotfile.com/dl/185675827/a61...nsfer.rar.html


Best Regards...

[macfly]

There should be no interface in your model.

Inner pipe surface BC should be set to wall.

Outer pipe surface BC should be set to wall as well.

[LuckyTran]

Originally Posted by macfly

There should be no interface in your model.

Inner pipe surface BC should be set to wall.

Outer pipe surface BC should be set to wall as well.

There should be interfaces. There should also be shadow walls.

Though I'm also not sure why the shadow walls are not appearing.

Edit
I managed to open the files. The mesh imported by Fluent is already incorrect. So the problem is in the mesh.

[wista59]

Originally Posted by LuckyTran

There should be interfaces. There should also be shadow walls.

Though I'm also not sure why the shadow walls are not appearing.

Edit
I managed to open the files. The mesh imported by Fluent is already incorrect. So the problem is in the mesh.

How can I fix it ? What I must do ?

[macfly]

Originally Posted by LuckyTran

There should be interfaces.

I did it without any interface. Look at the attached model with simpler mesh (I had some difficulties with the cylinder mesh...). It looks to me as if fluid dynamics and heat transfer are doing their job, the hot air in small pipe is cooled by the surrounding air. Boundary conditions for inner_pipe and outer_pipe are automatically set to 'coupled'.

Here are the files: http://dl.dropbox.com/u/64952262/z.zip

[LuckyTran]

Originally Posted by macfly

I did it without any interface. Look at the attached model with simpler mesh (I had some difficulties with the cylinder mesh...). It looks to me as if fluid dynamics and heat transfer are doing their job, the hot air in small pipe is cooled by the surrounding air. Boundary conditions for inner_pipe and outer_pipe are automatically set to 'coupled'.

Here are the files: http://dl.dropbox.com/u/64952262/z.zip

I also took a look at your's. You have the wall with corresponding shadow wall that forms the two-sided wall or interface between the two zones. The two-sided wall is a mesh interface that transmits information from one mesh zone to another, otherwise there is no ability for the two zones to interact.

But wista is missing the wall and shadow-wall pair forming the two-sided wall / interface and that is why it is not working. The two-sided wall is built by the mesher and must be present when it is imported into Fluent.

[macfly]

Yes, in ICEM CFD I created the blocking parts 'PIPE', 'AIR' and 'HOT_AIR', then the 3 mesh volumes are created when the Pre-Mesh in converted to unstruct mesh. Wista, check/uncheck everythig under 'Parts' in ICEM CFD and you will understand the mesh generation process.