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Ralf Schmidt April 28, 2009 10:15

patch data on a new mesh

I have a complex 3D geometry and did a number parameter variation simulations.
Now, i found out, that some BCs have to be separated for a more detailed analysis.

I took the mesh in gambit and separated these BC:
Without changing the mesh, I distinguish the existing BC: e.g. previously two touching faces are defined together as one "wall" BC, now they are defined as "wall1" and "wall2" (new declaration).

So the location and type of BC have NOT been changed (walls are still walls, inlet is still inlet), only the number and the declaration is different.

When I read that .msh file (with new BC declaration) in fluent and than read the .dat file from my finished simulations (with the old BC declaration) I get troubles assigning the solution.
e.g. the flow filed is available, but the wall fluxes are zero at the new declared wall BCs.

Now, when start iterating, the residuals are starting from a high value and the iterations take a lot of time to convergence.

How to patch the data from my old simulation to the new mesh????? I dont want to repeat all my finished simulations!!!


tengra April 28, 2009 16:43

You can interpolate data by writing from your old mesh and read in to your new mesh case file.

Ralf Schmidt April 28, 2009 17:04

I thing, thats what i have done...

I used the new .cas file with the old .dat file. But it doesn't work...

Or is there any other way?

tengra April 29, 2009 08:29

They way I said is below:
- Open your old case and data file in Fluent. Go to FILE->Interpolate>write and then give a file name.
- Then open the new case file in FLUENT, after checking grid, scale it properly. Then you go to FILE->Interpolate>Read and chose that file.
Hope it works.
By the way Ralf, what is your email, I would like to ask you some question regarding the effect of Y+.

Ralf Schmidt May 1, 2009 08:06


yes.. that works!!

I have to read the old .dat file as well to have the proper BC.
Additionally. it is necessary to define the BCs at the new declared walls.
And a few iteration steps have to be performed...

Thanks a lot!

I don't like to publish my email address.. but you can send me a personal message via my profile.

We did some investigations on the effect of yplus and the grid close to the wall. But, i am still analyzing data ... doing my phd about that... being very busy at the moment...


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