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-   -   [ICEM] Cartersian mesher failed (http://www.cfd-online.com/Forums/ansys-meshing/97111-cartersian-mesher-failed.html)

rikio February 9, 2012 02:52

Cartersian mesher failed
 
I am trying to get a 5:3:1 aspect ratio meshes with the method of Cartesian, by specifing the aspect ratio. But it always failed at the error message as below.

Cartesian mesher failed to create mesh
Loading domain "1201_BFCmesh.uns" ...
1201_BFCmesh.uns: 1201_BFCmesh.uns: error opening file 1201_BFCmesh.uns : No such file or directory

The manual tells that, the Cartesian mesher does not require an existing surface mesh and will ignore meshing parameters defined to control local surfaces. Then why prompt that no .uns file exists?

BTW, is there another way to generate a slim mesh except blocking? I am modeling a plane-like domain whose depth is much less than the length and width, and extruded mesh can not be used. But general tetra mesh would go to a too many cells solution. Specifing the aspect ratio would lower down the mesh size, but I always failed to get a Cartesian mesh.

PSYMN February 9, 2012 12:47

1 Attachment(s)
Worked for me...

Attachment 11223

More details please...

Could it be that you don't have write permissions where it is trying to place the mesh? It computes and saves the mesh before it loads it into ICEM CFD. I have often seen users fail because it can't actually write the mesh where it is...

Type pwd in the message window and make sure you can write in that location... If not, save the project to a location that you can write in...


On the other hand, I think you will get a better mesh for very little work in Hexa Blocking...

rikio February 9, 2012 22:32

1 Attachment(s)
Thanks for your comments, Simon.

After checking the log file, I found a message saying "Error: aspect ratio val must be > 0 and an integer". Then aspect ratio was changed from 5:0.2:1 to 5:1:1(sorry for the confusing message in my last post), and it works now. But I still have the following questions.
1. In Help Manual/Mesh/Global Mesh Setup/Volume Meshing Parameters/Cartesian/Body Fitted, it says: For example, setting the aspect ratio to 1 2 0.75 will result in a Cartesian mesh that is twice as long in the Y direction as the X direction and 0.75 times the size in the Z direction. It conflicts with the error message I encountered. Is it a misleading message?
2. How to estimate the cell size by considering Global Element Seed Size, Scale Factor and Aspect Ratio? I tried my model, and always resulted in a huge memory allocation which would down the system.
3. In the figure you posted, how to display the mesh as you did? Manually control or employ a built-in tool? Sometimes, such a picture is very useful to have a presentation.

In addition, I do not use hexa blocking here is because this model is just the simplest one of a series.And complicated geometries would be added for the comparison, as the attachments show. So I want the models to be meshed in a same topology. And it is also really a good chance to learn more mesh tools within ICEM. :)

P.S.: The version I am using is 13.0, Win 64-bit.

Thanks!


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