Inconsistent Shared Topology in SpaceClaim 2025R1 – Using Internal

[remi5.volley]

Hi everyone,

I'm working on a water cooling simulation in a complex geometry using ANSYS (SpaceClaim > Meshing > Fluent).

To define the fluid domain, I used the “Internal Volume” tool in SpaceClaim. So in theory, the geometry should be perfectly clean and aligned with the solid part — no gaps, no overlaps.

However, I’m facing a strange issue with Shared Topology:

• It works correctly on some surfaces (edges turn green),

• But on other surfaces, which are supposed to be identical and in contact, it doesn’t share the topology at all.

I’ve made sure that:

• The bodies are in separate components,

• “Share Topology” is set to Yes in Workbench,

• I’ve tried changing tolerances, using Imprint, Stitch, and Repair functions — but the problem remains.

This causes problems later in ANSYS Meshing (contacts not detected), and even errors in Fluent.

Has anyone experienced inconsistent shared topology behavior, even when using “Internal Volume”?
Is there a reliable method to fully share topology between two matching bodies?

Thanks in advance for any advice!

[remi5.volley]

As a result, ANSYS Meshing only detects contact regions where the topology was not shared in SpaceClaim. In the areas where shared topology worked correctly, no contact region is created (since the geometry is already continuous). This creates confusion, because the detected contacts correspond to the non-shared interfaces, while the properly shared zones are ignored by the contact detection tool.

[peteroznewman]

If you can share your geometry, I will take a look.  Reply with a link that anyone can use to download the .scdocx file.

If you can't share your geometry, please show some images of the problem.

I don't expect any contacts to be automatically created when shared topology is used and working. 

There can be a different tolerance for the Shared Topology to be created than the tolerance for contacts to be created.  Is that the source of your confusion?

[remi5.volley]

Thanks for your anwser.

I'm sorry, I can't share my geometry for privacy reasons. Rather, my problem is that I use the internal volume function to create my fluid volume, but sharing the topology doesn't work.

I've tried modifying my geometry a little to simplify it, but it still doesn't work.

[peteroznewman]

Why did you make sure the bodies were in separate components? I have found that putting all the bodies into a single component is a more reliable way to share topology.

Does your fluid volume contain a solid body?  In the example of a pump that I need to extract the fluid volume, there is the external casing that holds the fluid and an internal impellor that spins to create pressure.  I use a two step process to extract the fluid volume. First, I remove the impellor from the assembly and create the fluid volume. Second, I use the Combine button to cut the impellor from the fluid volume.

Maybe you can explain your process in detail using simple geometry that is not private.  The way you have described it above is unclear and you admit that you find it confusing.  Break it down to each step of the process and the individual bodies and components in SpaceClaim. If the simple geometry retains the share topology defect of the complex geometry, then you can share that.