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-   -   How to obtain the mesh size? (http://www.cfd-online.com/Forums/cfx/120003-how-obtain-mesh-size.html)

hustxinxin June 28, 2013 03:00

How to obtain the mesh size?
 
Excuse me

Is there anybody knows how to obtain the mesh size through User Fortran? I want to add a source term to the k-ω equation, and this term is a function of the maximum length of the mesh edges.

I am really appreciate your help!

ghorrocks June 28, 2013 06:09

Must be a strange source term....

This is difficult to define let alone code. CFX supports tet, pyramid, prism and hex meshes - are you going to code a different case for each of them? But even trickier is that the equations are solved on control volumes centred on the nodes, and these control volumes are polyhedral. Read the documentation for more detail on this. But it means the mesh you define is not the mesh it uses for solving the equations, so working out what the longest edge length on the original mesh would appear to be of little benefit.

hustxinxin June 28, 2013 06:43

Thanks for your kindly reply! :)
So, I worked out the problem with another method, that I used "Volume of Finite Volumes^0.3333" instead, and farther more, I think it's more approriate.


Quote:

Originally Posted by ghorrocks (Post 436518)
Must be a strange source term....

This is difficult to define let alone code. CFX supports tet, pyramid, prism and hex meshes - are you going to code a different case for each of them? But even trickier is that the equations are solved on control volumes centred on the nodes, and these control volumes are polyhedral. Read the documentation for more detail on this. But it means the mesh you define is not the mesh it uses for solving the equations, so working out what the longest edge length on the original mesh would appear to be of little benefit.



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