Error : Model facets are not well connected

[Anonymous]

Hi! Before telling about my problem, I want to give thanks for all of you for solving my previous questions.

I have another question about unsolving error message.

I have some 3D files (.obj, .3DS, .dxf), and I want to use these files to simulate.

I tried to use SimStudio to repair my .obj files and .stl files to adaptable files for CFD but SimStudio cannot amend my .obj and .stl files.

So I decided to use one of the CFD's tool, surface wrapping.

After surface wrapping, I cannot send this to CFD because of this Error message.

I interpret this message as to increase the resolution, so I maximized the factor to 10000.

However, it prints out same error message.

What should I do?

Please Help Me!

Thank you. 🙂

+I attatch screenshots for your better comprehension.

[Jon.Wilde]

Hi,

The surface wrap is only good for external aerodynamics, when you need to wrap a mesh around a solid part.

Here, it looks like you need to make a solid air part first.

Could you explain a little about the model you have, what you need to achieve and what the CAD looks like?

[Anonymous]

Thank you for helping me!

The final goal by using this model is to study the movement of a stream of water after colliding this surface.

I am designing the surface of new urinal, which reduces splash back compare to existing urinals. (There are other alternative surfaces, too. I want to do comparative analysis among these.)

This surface is made by using xyz coordinate system(I put function in program and it gives file of it to me.)

I thought I can use this file(the program provides lots of format, for example, stl, obj, 3ds etc) right away in CFD without using CAD.

I have a hard time handling CFD because I cannot ask question to people in my country.

Please help me with detailed procedure if possible. Thank you so much!

[Jon.Wilde · Accepted solution]

You would need a solid part to bring into CFD. This would actually be the fluid/air region.

I would try getting the solid into CAD first, then you can model the fluid region from there.

Actually, you could probably just draw a box around the solid and have an additional inlet somewhere where the water enters, should be quite simple to model that way.

Does that make sense?

Thanks,

Jon

[Anonymous]

Oh you mean put the surface in the box and simulate it? That can be possible, I will try it. Thank you so much!!

[Jon.Wilde]

Yes, but make it a solid first also... Somehow you need a solid part with your surface shape cut out of it.

I would use Inventor although I'm sure it is possible in Fusion also. I'll ask a colleague (a Fusion specialist) to check in on here 🙂

[Anonymous]

Thank you so much!!!

[Mike.Grau · Accepted solution]

Hi @Anonymous,

Thank you for asking about that.

Yes, we could help you to create your CFD Model in Fusion 360.

Please, feel free to download it. I have checked your account and you have valid Fusion 360 Ultimate subscription.

Could you may share your design with us via A360?

I have invited you to a shared Project where you can upload your design.

Please, let me know once you uploaded your design.

My Team mate in Singapore @ahreum.ryu could help you in your language 🙂

Thank you and all the best,

[Anonymous]

Oh thank you so much! Sorry for checking this reply today. sorry...

I'll send my files right away. THANK YOU FOR HELPING ME!

[Anonymous]

Good Evening! I posted some files in the project.

[Mike.Grau · Accepted solution]

Hi @Anonymous,

Thank you you for sharing your design with me.

I have converted the *.obj surface into a BRep with "Mesh to Brep" feature with the link here

Please, play the timeline and analyze how I did proceed after the conversion.

As you can see, I have had to un-stitch the elements multiple times for a final stitch, since I had multiple free edges within the surface area.

Just an simple extrude created a solid volume.

I hope this helps.

Thank you,

[Anonymous]

Thank you for helping me!...After I put this solid .obj file(that you uploaded in A360, Mesh_to_Brep file) to CFD to simulate, I got the same error as before. What should I do?

Also, I tried to follow the stages that you uploaded in A360, I cannot know what you did at version 3 and 4. Can you elaborate it more?

Can your team mate help me to solve this problem? I can understand the solutions more easily when I ask the problem in Korean.

Thank you!

[Mike.Grau · Accepted solution]

Hi @Anonymous,

Thank you for your feedback.

I have finalized the design and made it ready for CFD.

Please, use the latest version v7. 

I would need a bit time to create a screencast how to design CFD models within Fusion 360. Basically I use all Model, Sketch and Patch features to close and repair the geometry.

I hope this helps.

Thanks,

[Anonymous]

Wow, it seems that I begin to see some light at the end of the tunnel. I want to simulate this in my computer as fast as I can.

I checked the file that you uploaded, version 7. I download this file in format .obj but I cannot simulate this in CFD.

What type of format did you use to simulate? 

Thank you very much for your kindness! 🙂

[Mike.Grau · Accepted solution]

Hi @Anonymous,

Thanks for asking.

Sim CFD can only work with surface / geometry information like *.step, *.iges etc. files.

Do not import any mesh files like *.obj or *.stl which can´t be meshed since they are already a mesh 😉

I hope this helps.

Thanks,

[LKania]

STL files can be imported and remeshed owing to the new discrete model workflow first appearing in the 2017 release. The imported representation must describe a closed, "water-tight" set of one or more solid objects. A surface alone will be reported as not well-connected as you will have numerous triangles that have no neighboring triangle across one or more edges.

Note, however, that stl-based model import is not as robust a workflow as the one employing the surface wrapper. The latter is the preferred workflow as it will make accommodations for certain defects within the imported representation (even stl models). That is, imported models with slight imperfections may still yield a valid set of solids with use of the surface wrapper.

Lastly, it may be possible to successfully import an stl description for a surface into Autodesk CFD via the surface wrapper environment by proper positioning of the external bounding box such that all edges of the surface coincide precisely with a boundary of this box. Though I have not tried this myself, it may yield upper and lower solids separated by the imported surface - assuming such an arrangement satisfies your modeling requirements. 

[Anonymous]

Now, I can successfully open the file in CFD. Thank you SO much.

I want to try another alternative surface to compare with it, 

but I cannot fully understand the process change .obj to solid.

I know how to change mesh to B-wrap, but I cannot fit it into closed box.

Please explain this a little bit more.

I am enormously grateful for your help. Thank you so much.

[Mike.Grau]

Hi @Anonymous,

Thank you for asking about that.

Could you upload the new file in the Project which I have shared with you?

I would go ahead and create a Screencast this time 😉

I think it is important to learn the basic CFD modeling techniques before I will mention further advanced tools.

Thank you,

[Anonymous]

I posted one .obj file and one .stl file that you converted to solid before. (and also another .obj and .stl files)

Please check them! Thank you!