SimScale CAE Forum

Mesh generation issue


#1

hello, since Friday meshes can’t be generated from the geometries a few friends of me and myself are uploading, the mesh log states that there are twisted faces
we even tried creating a mesh from geometries we had already created a mesh successfully but the same errors occurred.
Here is a link to my project : https://www.simscale.com/workbench/?pid=1641314780783718980

edit: the settings remain the same as with the other geometries since i duplicate the mesh and change the geometries


#2

Hi @apotlr!

Do you mean the “copy_of_splitter” mesh? Somehow the geometry is not closed - @yosukegb4, can you quickly inspect the geometry please and tell where the problems are? Thanks a ton!

Note to self: Get Rhino before 2025.

Cheers!

Jousef


#3

yes that’s the one that uses the same geometry as the very first one (serrated&bargesides) but the mesh failed the second time


#4

Hi @apotlr,

I suspect you have reached your data storage limits. You might need to delete off other projects or meshes/geometries/simulations within the project/account before trying again. The mesh is actually ok and is actually really good quality despite the complexity. Try my suggestion out and see if it works.

Cheers.

Regards,
Barry


#5

hello,
after trying what you suggested and doing some extra research trying to create the mesh from every solid body of the assembly separately we still can’t figure out what is happening. Every body seems to be able to be generated as a mesh just fine on its own.
The wheels seemed to be problematic, when we generated the mesh with the whole car ( plus the wheels) it failed though without them it succeeded but when i uploaded the wheels separately the mesh was generated just fine.
by separately i mean three different stl files were uploaded, one for the front axle, one for the rear and one with both of them
we also tried all the combinations with bodies that had some intersections (wheels not included) but the mesh was generated successfully
thank you for the help


#6

Hi @apotlr!

Did I understand that correctly that you uploaded the parts separately? If so then please merge the STL files which can either be done with a script or use Onshape for this which is nice as you then can use the SimScale plugin to import to the model from Onshape to your project. By the way, you can find good templates for FSAE simulation in our public projects section like this one here: Full Car Aerodynamics.

Let me know if you have any further questions and if I forgot to explain a specific point.

Jousef


#7

hello,
probably i wasn’t clear in my explanation or i didn’t understand correctly your last message :sweat_smile:
in general we upload as a single stl file the 4 aerodynamic devices ( as 4 separate bodies) plus the chassis as a separate body as well, etc. All in one stl though.
But to exclude any possibility of a problem with the geometries we uploaded every body as a separate stl and the mesh for every body was done successfully
Does your suggestion still stand?
Thank you for your time


#8

Hi @apotlr!

I do not fully understand the problem but you cannot mesh components separately and assume that just all succeed that the components in the assembly will also result in a perfect mesh. You would have to mesh the whole car and then make adaptions and your convergence studies :slight_smile: If I misunderstood you maybe make it clear with a step-by-step instruction or “plan of attack” that you are trying to follow. All the meshes except the last one succeeded - can you tell me which model you are trying to mesh (as you have many in your project)? Makes things a bit easier :slight_smile:

Cheers,

Jousef


#9

hello,
I am actually trying to mesh the last one (just renamed it to benchmark)
Unfortunately i deleted previous failed mesh attempts, but the thing is that the exact same geometries that had their mesh generated previously, when we try to regenerate it using the same settings, since Friday it fails. I figured that out after many failed attempts to produce the benchmark mesh
So back to these attempts, we tried to eliminate any issue with our geometry that we could think of, that’s why we uploaded each body of the assembly separately. If it can’t be generated on its own then it shouldn’t be generated in an assembly although as you said it doesn’t work the other way around.
I will be starting mesh creation for a previous assembly that had its mesh successfully created so that you can take a look at it, the geometry will be the flow_v1, the original mesh is flow_v1 and i will name the today’s mesh flow_v1.2
I appreciate your time!


#10

Sure @apotlr!

I will wait for your feedback and until you re-meshed the geometry. Please keep all the meshes and give them meaningful names also that we can communicate more efficiently which saves us time.

Cheers and happy SimScaling!

Jousef


#11

So i renamed the meshes to original mesh and regenerated mesh.
The original mesh had found a few non orthogonal faces but didn’t fail to finish, however the regenerated mesh having found the same illegal faces failed to finish. To my knowledge, this phenomenom has occured to similar pairs of meshes without any of them finding illegal faces


#12

Hi @apotlr!

Can you please try to split the components of your car? With that I mean surface splitting which might cause some weird behavior and also an erroneous mesh as in your case. For instance your rear wing is one whole component. You can either use the split operation here on our platform or use the one in your CAD system - just one that you’re familiar with and show me the new geometry before you mesh it! I will have a look at it.

Cheers,

Jousef


#13

hello @jousefm
I tried the surface splitting on simscale as demonstrated by another colleague of yours in a thread i found, but the operation failed again. the feature angle I used was 85 but there was no event log created so i can’t figure out what is wrong. I tried the chassis, on the benchmark geometry and the dummy on the flow_v1.

Thank you for your help!


#14

Hi @apotlr,

can you try splitting the surfaces in your CAD software? Which one are you currently using? Maybe the @PowerUsers_CFD can help you out here.

Cheers,

Jousef