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-   -   (Dynamic) Mesh Modification (http://www.cfd-online.com/Forums/fluent-udf/69844-dynamic-mesh-modification.html)

Mr. Joe November 6, 2009 09:13

(Dynamic) Mesh Modification
 
Hi!

I've a general question about the modification of existing meshes. Is there another method of modification than a dynamic mesh udf? Because I need to modify my mesh after each 1000 iterations in a time steady calculation. I think dynamic mesh is only working in transient mode???

Thanks,
Joe

gearboy March 1, 2010 05:31

Quote:

Originally Posted by Mr. Joe (Post 235355)
Hi!

I've a general question about the modification of existing meshes. Is there another method of modification than a dynamic mesh udf? Because I need to modify my mesh after each 1000 iterations in a time steady calculation. I think dynamic mesh is only working in transient mode???

Thanks,
Joe

Dynamic mesh can be applied to steady case. DEFINE_GRID_MOTION and other mesh motion macros are also available. See the fluent manual for details.

In the steady case, you can use the following macro to tell fluent to update the mesh as the "DEFINE_GRID_MOTION " or other mesh motion macros instruct at the end of each iteration. Of course, do not forget to hook it in fluent.

DEFINE_EXECUTE_AT_END(update_mesh)
{
CX_Interpret_String("(steady-update-dynamic-mesh)");
}

TDi March 23, 2010 14:25

Quote:

Originally Posted by gearboy (Post 247864)
Dynamic mesh can be applied to steady case. DEFINE_GRID_MOTION and other mesh motion macros are also available. See the fluent manual for details.

In the steady case, you can use the following macro to tell fluent to update the mesh as the "DEFINE_GRID_MOTION " or other mesh motion macros instruct at the end of each iteration. Of course, do not forget to hook it in fluent.

DEFINE_EXECUTE_AT_END(update_mesh)
{
CX_Interpret_String("(steady-update-dynamic-mesh)");
}

I have spent a lot of time perusing the Fluent manuals looking for function references but without success. "CX_Interpret_String" is not a C function, and I can find no reference to it in the Fluent user manual or UDF guide. I'm also trying to define grid motion, but the examples are full of functions that I don't know anything about, so I feel limited to what the examples do. What is your source of information?

gearboy March 24, 2010 21:31

Quote:

Originally Posted by TDi (Post 251312)
I have spent a lot of time perusing the Fluent manuals looking for function references but without success. "CX_Interpret_String" is not a C function, and I can find no reference to it in the Fluent user manual or UDF guide. I'm also trying to define grid motion, but the examples are full of functions that I don't know anything about, so I feel limited to what the examples do. What is your source of information?

CX_Interpret_String is a UDF function to perform scheme command in UDF. But not every scheme command can be performed.

(steady-update-dynamic-mesh) is the scheme command to tell fluent update the steady dynamic mesh.


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