Dale,
I have not checked the mesh quality parameters as do not have OF installed. I have never used the native OF but i am aware that it can check the mesh quality.
I can easily lower the illegal cell count by changing the max non-ortho Quality setting to 75 deg, but im still not sure if that has the desired effect.
My simulation setups and methodology is as follows:
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I performed all my Non-ortho reduction testing on the wheels as they had a significant amount due to the geometry. This is found in my thread here
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I used my research and new strategies to create a successful 1/2 car mesh to validate the results. This project is here
The half car simulation was done with max non-ortho quality of 70 deg, which resluted in the following illegal cell count.
Checking faces in error :
non-orthogonality > 70 degrees : 2682
faces with face pyramid volume < 1e-13 : 15
faces with concavity > 80 degrees : 1
faces with skewness > 4 (internal) or 20 (boundary) : 4
faces with interpolation weights (0…1) < 0.02 : 0
faces with volume ratio of neighbour cells < 0.01 : 3
faces with face twist < 0.01 : 15
faces on cells with determinant < 0.001 : 0
This project was also the original testing ground for my radiator fan / rad fan MRF zone testing. Since this was successful, my plan was to simply make a full car sim because i naively though that this would work no problem
And the stable results with default settings for relaxation factors, with one non-ortho corrector loop
Force plot
Coefficients Plot
These results made me think that all was well and good … NOPE.
After the first attempts at a full car simulation (with yaw, pitch, roll, and steering angle) i knew this would be a battle. I immediately had mesh failures, due to memory problems.
- I reduced the region refinement settings which fixed this
Once the mesh began to work it failed again due to the 3 adjacent faces problem.
- with support from the Simscale staff i was able to get the locations of these points on the geometry and fix it.
Then i finally get a 20 million cell mesh to work, with rotating fan assembly and all… Simulation ran out of memory.
This led me to delete the fan assembly to gain some cells back as a buffer. Since i changed this geometry, the 3 adjacent cell problem came back.
- again receive quick support from Simscale staff … geometry fixed … good mesh.
Simulate results - wildly wrong results as you saw in the links from my first post.
Now i am still confused because my half car sim with half the illegal cells (2682) worked just fine, so i dont think thats the problem … but i have no idea.
So to conclude. I have a more complicated mesh working with converged results that also has a large number of Non-ortho cells.
Dan