snappyHexMesh: problems with layers
Hi Foamers.
I'm a beginner of OpenFoam.I'm trying to simulate an internal airflow of an airbox in a racing car. I exported the geometry in .stl ad i'm trying to mesh with snappyHexMesh.At present i'm in trouble because i can't understand why snappy doesn't add layers! Any suggestion is really appreciated Here the snappyHexMeshDict Code:
/*--------------------------------*- C++ -*----------------------------------*\ |
Why do you have sistema_aspirazione_OBJ instead of sistema_aspirazione for the layers?
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Because i called my .stl solid OBJ!
I try to explain better: i saw on others snappyHexMeshDict that usually the user defines the patch of .stl surface adding OBJECT(no matter if i write OBJECT or OBJ or PIPPO..it's just a "name") in the first line in the .stl file next to "solid". I emphasize: i'm a beginner! :P Is that wrong? p.s. at the moment i'm not in my place.This evening i'll try and i'll let you know if changing what you have suggested works! Thanks a lot Giulio |
You haven't defined that name anywhere…
What you have is the following: Code:
sistema_aspirazione.stl So for the layers to be added on your patch you need: Code:
layers |
Ok.Thank you!The problem still exists but you open my mind! :D
I realize that snappy recognizes just a patch named "sistema_aspirazione_solid"! So i changed the name of my patch but the addition of the layers is still a failure.While on the terminal i read that the layers have been added, by paraFoam i see that have not been added. Any ideas? I've got another question: I want the mesh face is getting thicker as you get closer to the surface. Is that right? Quote:
Giulio |
Yes, that should do the job.
About the layers, I think some of your settings are wrong, such as this one: Code:
finalLayerThickness 1e-3; Also, have a look for the word "layer" in your sHM log as I think it may have not done the layers at all. I would suggest you to try these settings here that worked for some of my cases. If you want to change something, do that with one parameter at a time to see the effects of each and also remember to clean the case before running snappy again. Quote:
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3 Attachment(s)
Thank you so much lovecraft22! Now i can actually see that the layers have been added.But i still have others duobts.
This Quote:
I see that the mesh is very irregular and the surface presents different refinement zones.What's going wrong in the code? The layers addition involves just the 99.3% of the surface, not 100%, and this is not good because i've critical zones where there's no layers!(e.g. throat section of the restrictor). In addition the layers seem to have different dimensions.How is it possible? Below the code: Code:
addLayersControls |
I think you should probably try and increase your mesh resolution to see if you can get the layers everywhere.
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Quote:
Anyway i'll try and i let you know. Again thanks for your invaluable help |
This:
Code:
sistema_aspirazione |
Now i'm setting up finer levels
Code:
refinementSurfaces What about this? Quote:
Here the latest code. Code:
/*--------------------------------*- C++ -*----------------------------------*\ |
Now i'm setting up finer levels
Code:
refinementSurfaces What about this? Quote:
Here the latest code. Code:
/*--------------------------------*- C++ -*----------------------------------*\ |
I dont' think the problem to be the stl. The layers always come out with some region where they are missing unfortunately…
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Quote:
What do you think about the quality of my mesh?Just an opinion..isn't too irregular(bulk,layers..)? Thanks for your kindness Giulio |
From the first image you posted I can see there's too much of a difference between two closed regions on the mesh of the external surface. From the other images there's also a bog different between the cells by the surface and the ones by the center line.
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lovecraft what about decomposeParDict?I've got an Intel Processor i5 3,0Ghz!How can i set my decomposeParDict?
Thank you Giulio P.S. i see the icon "send a message via Skype to lovecraft22"...can i contact you(I would not be annoying)? |
You need to chose a decomposition method along with a number of subdomains in your decomposeParDict, run blockMesh then decomposePar then snappyHexMesh (or whatever you need to run in parallel) using mpirun.
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I ask you some questions again:
Quote:
Code:
refinementSurfaces Code:
/*--------------------------------*- C++ -*----------------------------------*\ P.s. i realized that my .stl is composed of 13 parts!!!!I can't understand... Code:
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