mesh file generated by pyprimemesh cannot be used for Conjugated heat transfer simulation in Fluent

[Jinge91]

Hi dear,

I am developing a automatically simulation-optimization process and want to use pyprimemesh generate mesh for CAD and then use Fluent for running simulation.
I am able to generate a good quality mesh and import it into Fluent(I am not working in Workbench), but the Fluent won't automatically create proper wall setting for me so when the simulation complete, there is no heat transfer results.

What should I do in pyprimemesh so that Fluent will automatically create proper wall setting like the Workbench mesh.

The first picture is the wall setting when I import mesh file generated by pyprimemesh.

The second picture is wall setting when I import mesh file generated in Workbench.

[waltersma]

Hi @Jinge91,

It appears from the information you have shared that it is assigning a default wall boundary in the first instance and you have a named zone with wall and wall shadow in the second?

With only this information I would have to guess a little but in the first case I would expect that you are not seeing wall + wall shadows because all the walls are external. Please check the connectivity of the case. The different volume zones you are expecting and whether they are connected correctly. You may require shared topology. If so please remember to import using WORKBENCH cad reader route to preserve this. For example:

params = prime.ImportCadParams(  
    model=model,   
    cad_reader_route=prime.CadReaderRoute.WORKBENCH  
)  
prime.FileIO(model).import_cad(file_name=cad_file, params=params)

For the second issue of the zone names. Are you assigning zones before exporting? Do you have named selections or labels on these walls that you are defining? A straight forward way to define all of these at once is to use something like the following:

prime.lucid.Mesh(model).create_zones_from_labels()

I hope this helps!

Regards

[Jinge91]

Hi @waltersma,

Sorry for the late reply since I changed to the Workbench CAD reader route then I need to rebuild my mesh generation strategy, so it took me quite a while to figure out a fine enough quality mesh for Fluent.
And it turns out that you are RIGHT! Using Workbench CAD reader route helps Fluent to generate wall+wall shadows in my case. Even I just label the inlet and outlet like this:
mesh_util.create_zones_from_labels("inlet, outlet")

but anyway, I got a proper wall +wall shadows now and Fluent was able to do the heat transfer calculation.

Really appreciate you!!

And I have a follow up question: my CAD was built in [millimeter] but pyprimemesh read it as [meter]. I change the unit while read the CAD, but it doesn't work:
file_io = prime.FileIO(model=model) read_param = prime.ImportCadParams( model=model, length_unit=prime.LengthUnit.MM, cad_reader_route=prime.CadReaderRoute.WORKBENCH ) file_io.import_cad(file_name=coldplate, params=read_param)

[waltersma]

Glad your first issue is resolved! We can open a separate issue about the scaling you are seeing. Please provide details on the CAD format you are reading. Thanks!

[Jinge91]

Sure! I will post a new discussion!