Learning Forum

[LTIIT]

Hi there,

I'm using Ansys student version to generate a radial compressor mesh coupled with a back face cavity.

Now, there is this nice functionality of generating a 2D mesh of the secondary flow path and coupling it to the main 3D mesh.

So far, everything works fine: Generating the compressor and secondary flow path geometry using design modeler, assigning the secondary flow path and boundary intersection. I have both, the boundary intersection and the rest of the closed loop inside the Mesh tab under secondary flow path. As long as the secondary flow path is not interfaced with the 3d mesh, everything works fine.

However, as soon as I select "hub interface" for the boundary line, mesh generation crashes with the attached error.

I've tried the following:

• moving the boundary outside the blade passage and to the outlet domain
• first suppressing topology update
• Changing the angular position of the interface
• Reversing the rotational direction of the machine
• Using "Export Points" and "CAD" for blade geometry and flow path geometry respectively

Whats the solution? If there is no interface between the two domains, the functionality is useless.

[rfblumen]

Are you using the latest Ansys version (2022R1)? I would suggest trying that to see if the issue is related to a defect that was fixed in a later version.
Issues can also occur if there's a gap between the secondary flow inlet/outlet and the main flow path. To avoid this, you can purposely generate a small overlap in DesignModeler such that the secondary flow path inlet/outlet extends inside the main flow path meridional space by a small amount.
I also found it helpful in one particular case to make the secondary flow path inlet/outlet curve non-parallel to the main flow path hub/shroud curve (viewed in the meridional plane).

[LTIIT]

Hi, thanks for the answer!
I suppose overlap between the domains may help; in the meantime I fixed the problem by simplifying the gap domain (only a quadratic cross section, which is then coupled to another gap domain generated with unstructured mesher).
I'll try your suggestions anyhow...