Hello,

I'd like to simulate radiation heat transfer between the walls in a rectangular duct. I created the channel inner surfaces with ICEM. Since radiation "only" depends on the surfaces I generated a 2D mesh : Create block > 3D Bounding Box > 2D Blocking. After setting the node distribution along the edges I converted the Pre-Mesh to unstruct mesh. So far, the mesh looks nice. But when I try to create the output for CFX I get an error-message:

"Error: Running ICEMCFD-CFX Interface Vers. 10.0.01 Error: no volume elements found. child process exited abnormally"

From another topic in this forum I've learned that "CFX5 is a 3D solver. It cannot use a 2D mesh." http://www.cfd-online.com/Forum/cfx_....cgi/read/8620

When creating a 3D-mesh (the space between the channel walls too) everything works fine! But the number of nodes becomes very large and I don't want the media (air) to participate in the Monte Carlo simulation.

Can anyone give me an advise?

Thank you! Zoran

ANSYS CFX 11.0, ICEM 11.0 - no SP1

It's me again,

I found another topic that relates to my problem: http://www.cfd-online.com/Forum/cfx.cgi?read=23140

The essence is: "CFX cannot read 2D meshes. [...] extrude a 2D mesh for one element and put symmetry planes on top and bottom. This is explained in the documentation."

Now I have 2 options: go ahead with the full 3D-mesh (# of nodes!!!) or extrude the 2D-mesh for 1 layer.

What are the pros and cons? Which one is more recommended for the followed MC-radiation simulation?

Zoran

You can probably extrude your 2D mesh into 3D by extruding only one layer. Then you probably need to specify the symmetry or periodicity in CFX-Pre. After extruding the 1 element thick - you'll need to place the new bounding 'walls' into appropriate parts for boundary conditions. CFX will do the 2-D calcualtion - but it needs to be 1 cell thick.

Thank you Myron!

Indeed, the 2D mesh has to be extruded by 1 layer (ICEM: Edit Mesh). Doing this, one has to pay attention to the direction of the extrusion (for "extrude by element normal" use the "reverse direction" box) in order to avoid overlapping of mesh elements (in my case: rectangular channel). In addition, I extruded the mesh for each part separately to insure a proper association.

I didn't specify any symmetry or peroidicity (still don't see the idea behind). However, the output file of this 3D mesh can now be created and opened in CFX-Pre without problems.

I hope this helps in future to other newbies.

All the best, Zoran

[nanoengine]

Originally Posted by Zoran
;84649

Thank you Myron!

Indeed, the 2D mesh has to be extruded by 1 layer (ICEM: Edit Mesh). Doing this, one has to pay attention to the direction of the extrusion (for "extrude by element normal" use the "reverse direction" box) in order to avoid overlapping of mesh elements (in my case: rectangular channel). In addition, I extruded the mesh for each part separately to insure a proper association.

I didn't specify any symmetry or peroidicity (still don't see the idea behind). However, the output file of this 3D mesh can now be created and opened in CFX-Pre without problems.

I hope this helps in future to other newbies.

All the best, Zoran

please anyone who can explain solve of this problem with screenshoot
please