Learning Forum

[asendero]

I am trying to do an MRF simulation of a stirred tank. I made my geometry in Solidworks, and it has four parts (tank, shaft, impeller, and rotating zone around the impeller). Originally, my tank had a lid which gave me issues using the Share Topology function on the interface of the hole where the shaft went through. I ended up just taking the lid off the tank to avoid those issues. When I examine the lid-less model in SpaceClaim, it doesn't show any coincident topology, so I can't use the Share or Force Share functions, but when I try to mesh it in Fluent, it insists that there is coincident topology, but when I try to apply the Share Topology function in the Fluent mesher, I get this error:n462 self-intersecting triangles exist in the model, which is above the limit for automatic smoothing ( 10 ).Either CAD plug-ins (instead of CAD readers) were used, which sometimes lead to a Multi-body-part topology, or Share Topology in SCDM/DM failed at certain locations. In the latter case, make sure to invoke Forced Share option in SCDMnThis is my first model in Fluent so I have no idea how to fix this! I have run this model both on my university's virtual computer lab so on the university's license, and on a student version I downloaded and had the same issues each time. Both the Solidworks geometry model and ANSYS Workbench are version 20 so I don't think that's the issue either, and the Solidworks model was uploaded to Fluent as a STEP file.nThank you so much!nn

[Keyur Kanade]

Please have a look at nRegards,nKeyurnHow to access Ansys Online Help DocumentnHow to show full resolution imagenGuidelines on the Student CommunitynHow to use Google to search within Ansys Student Communityn

[asendero]

Hi, thank you for the response. I tried including some of the things mentioned in the video (boolean operations), but I am still running into the same errors, even though SpaceClaim does not show any coincident topology anymore. I am attaching the SpaceClaim geometry screenshots of when I try to apply the Share and Forced Share functions. I tried applying the Share Topology function in Design Modeler, but that did not solve the error either.nArrayArrayn

[Keyur Kanade]

As ANSYS Staff, we can not download attachments. Please upload images using upload image functionality. n

[asendero]

n

[Keyur Kanade]

You can have one file with rotating zone (A) and another file with other zones (. nMesh A and export A.mshnMesh B and export B.mshnOpen Fluent, read A.msh. Then append B.msh.n

[asendero]

I don't think this would solve my issue, since the topology issues are between the shaft and the tank, not the rotating zonen

[Rob]

Why are you retaining the shaft and impeller in the model? We'd typically just consider the fluid domains. nAlso check the CAD faceting as that can play a part when the curvature is high, default is 5, 10 is often better. nn

[asendero]

What do you mean by retaining the shaft and the impeller? Does that mean I should be doing a volume extraction and then meshing that, or that in the Fluent Mesher I should set that the model contains only fluid domains, which is the setting I have been using.nnI just tried upgrading the rendering, but unfortunately it didn't seem to make much of a difference. I still get this error when I go to mesh the model even though no contacts or coincident topology appear in SpaceClaim when I try to use the Share or Forced Share functionsnn

[Rob]

That looks like you've got the vessel solid and impellor solid, can you confirm you have two fluid regions? Ie the cylinder around the impellor & the main vessel. n

[asendero]

Yes, I have a smaller fluid region around the impeller which is enclosed by a cylinder that's going to be used for the MRF, and then the fluid outside that zone but still inside the tankn

[Meisam Mehravaran]

Any updates, or solutions to this problem? If these intersecting errors exist in fluent mesh, why they never give an error/warning in SCM so we can fix them?

[Nikhil Varma]

 

Yes the sharedtopology and intersection failures are a major bottleneck while using Spaceclaim for me also. I wish there was a solution for this.