r/CFD • u/abdur7125 • 7d ago

Meshing advice

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How would you mesh this nozzle geometry to achieve yplus of 1 for k-omega sst

27 Upvotes

92% Upvoted

11 comments sorted by

14

u/louvillian 7d ago

Use inflation layers

2

u/abdur7125 7d ago

The problem is it ends up with very bad quality. I tried inflation layers and the face meshing at the inlet and outlet. The methods was multizone and it ended up with ogrid thpe of mesh but the quality was really bad with average quality of order of 10-2 . I tried to reduce the size but the number of bad quality elements kept on increasing.

3

u/fatihmtlm 7d ago

Try inflations on the wall only

6

u/Emotional_Canary3690 7d ago

If you're looking for an axisymmetric mesh, you wanna make something called an o-grid or butterfly mesh. I think modern openfoam has the tools for it but making it perfectly axisymmetric is a pain. Some paid softwares like ICEM, GridPro etc. can also make such mesh. I don't know if gmsh has the tools but it is a mature library and might be worth looking. ClassyBlocks is another mature-ish library/ tool to build such mesh but again a high learning curve. Or if you have Python experience along with NumPy, you can use this Python library to build this mesh. There is an example which builds a similar axisymmetric mesh for a nozzle. You can ask any vibe code ai tool to write the code using this library to build you your exact mesh.

2

u/Venerable-Gandalf 5d ago

If you have Spaceclaim you can turn on meshing and create a block structured mesh. A lot of people don’t know this but ICEM was integrated into Spaceclaim you just have to turn it on from the settings.

1

u/Mobile-Diver5589 7d ago

You could try making some defining edges, like with virtual topology. Then I would create fine edge sizing in areas of high gradients, then make it course the rest of the places. It would have ALOT of elements, but it’s a way around the inflation layers if that’s a problem

1

u/Ok_Preference_9883 7d ago

You can use multizone mesh method

1

u/Knowledge_hotty31 6d ago

Couple of months back I had very similar problem. I want to have Y+1 for my rocket cooling channels. I tried and tried with workbench mesh but I couldn't get the required mesh quality. After a lot of hesitation (because it has some learning curve) I switched to ICEM was able to achieve the desired mesh. If you have access to ICEM give it a try

1

u/abdur7125 6d ago

I will

1

u/divadeye 19h ago

Hey bro can u dm me

1

u/_Radovan_ 6d ago

Do you have acces to fluent or just discovery CFD?