Mesh quality check for VWT
Altair EmployeeIn the introductory video for VWT , it was specified that even if the mesh quality is bad enough still VWT gives quite a reliable solution for the model we are trying to simulate. But it won't be absolute
I want to ask that which parameters in the quality check of mesh do we have to take care of to get the best simulations of a race car(identical to real life)?
Of these mentioned below in the image file
<?xml version="1.0" encoding="UTF-8"?>
Answers
-
I would suggest following checks:
- Connectivity
-Duplicates
- Min Angle < 5°
- Length < 0.001 (assuming the model is in meters) This check will highlight all elements less than 1mm length.
1 For surface meshing, you will want to resolve any feature on the vehicle with at least 5-10 elements. So if the feature is 100mm then use a 10mm surface element.
These checks would give you a good surface mesh.
0 -
Why do you deny using a mesh with small element size? Won't a finer mesh give me better results? I just have a doubt about the length criteria. Why such a limit on smallest length?
0 -
The reason I avoid very small elements is that, generally it can mean a skewed element.
Fine mesh generally gives a better results. But in CAE world, we have to be practical as well
/emoticons/default_wink.png' srcset='/emoticons/wink@2x.png 2x' title=';)' width='20'>
The finer we mesh the more compute resources and time it would require to get a solution.
0 -
My mesh of the car didn't have min angle>5degree. No duplicates, free edges, penetrations and fully connected but my mesh is not running in VWT. So how do I run them. Very less number of elements are less than 5 degree so it's okay if I get very small errors, it would be very small. But it won't run. So is less than 5 degree a compulsion?
0 -
No it is not a compulsion to have all elements less than 5 Deg.
Could you send a screenshot of the run folder? Do you see CAD.DIR, MESHSIM.DIR etc folder?
If vwtAnalysis.MeshSim.txt and/or vwtAnalysis.1.Log is generated, please upload.
0 -
There were intersections. Cured them. What is this msg? Purged 252 lines. Current limit of 100 exceeded.
0 -
It still shows mesh_intersections dat and nas files. All things are great!
What's the error here?
0 -
Altair Forum User said:
There were intersections. Cured them. What is this msg? Purged 252 lines. Current limit of 100 exceeded.
Could you upload the file that has this error?
A screenshot of your run folder would be also helpful.
0 -
Altair Forum User said:
It still shows mesh_intersections dat and nas files. All things are great!
What's the error here?
This file has only geometry. No mesh.
0 -
Oh yes. Sorry Y-digit. I found the errors. After I corrected the intersections, free edges arose. Trying to solve them!
0