Topological error importing .iam from inventor into cfd sim

[pumpkinboy1991]

Ok, so I have 2 parts (hull.ipt & cockpit_sides.ipt), both of which are modelled as fairly simple sculpted solids for the sake of CFDing them. In the assembly file I basically have the cockpit sides constrained to the topside of the hull and located using work points/grip snap. If I open the cockpit_sides.ipt in simulation by itself, it renders correctly and there is no issues. However, anytime I try to import the assembly of the hull and cockpit sides together, it always brings up a topological error and only displays the hull. I've tried making a fresh cockpit sides part from scratch to see if there was some strange geometry affecting the file but the same error occurs every time. I've never had this issue when importing assemblies into simulation before but this i don't have a clue how to stop! Any help would be appreciated.

Ollie

[Jon.Wilde · Accepted solution]

Hi,

I would say this is down to how the two parts meet (especially as they both launch OK individually).

There is a surface on either side which tends to zero and maybe overlaps too (I am not sure). Could this be simplified at all? I think if this join was tidier this should launch properly.

Edit: A crude solution but if I add a cut to tidy these edges, it launches fine (the design looks pretty starship like too 🙂 ).

[LKania · Accepted solution]

If you first adjust the model conicidence tolerance (via the user flag AsmCoinTol) to 1e-5 prior to import, the assembly will import successfully, but the features wildej has pointed out will persist. If you autosize the model for meshing, you'll have to make provisions for these surface slivers by refining the edge distributions accordingly.

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@pumpkinboy1991 wrote:

Ok, so I have 2 parts (hull.ipt & cockpit_sides.ipt), both of which are modelled as fairly simple sculpted solids for the sake of CFDing them. In the assembly file I basically have the cockpit sides constrained to the topside of the hull and located using work points/grip snap. If I open the cockpit_sides.ipt in simulation by itself, it renders correctly and there is no issues. However, anytime I try to import the assembly of the hull and cockpit sides together, it always brings up a topological error and only displays the hull. I've tried making a fresh cockpit sides part from scratch to see if there was some strange geometry affecting the file but the same error occurs every time. I've never had this issue when importing assemblies into simulation before but this i don't have a clue how to stop! Any help would be appreciated.

Ollie

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[pumpkinboy1991]

Thanks for the help both of you, sorted now 🙂 Not sure about starship.. but it'll look something like this when it's complete!

[Jon.Wilde]

Neat! Where to I sign? 😄

[LKania]

Cool! When build kits are available, let me know.