Hi everyone I will be documenting and experimenting on how to get the optimal mesh quality for an FSAE half simulation (and eventually full car) with focus on important parameters such as: Total mesh cell count - (dont want too many core hours / memory failure with 32 processors) Y+ Layer forma…

[image] dschroeder: I used meters (m) and not millimeters (mm) because i assume Simscale needs to have these numbers in meters (m). Although I have seen SimScale have many problems when using English vs SI units, I have NEVER seen SimScale ask for meters when it wants mm… In fact, I have I h…

Thanks Dale! Yea i definitely understand a whole lot more of how this works because of your help. Im not expecting to get this perfect either, just close enough to say i can stand by the results. For the Y+ distance. You have suggested 50, and now maybe 100, which i assume is so that i can success…

[image] dschroeder: I think i will need to export to Para view because i dont understand how the simscale Y+ viewer works with the (what seems to me) like a backwards Y+ display with 0 farthest from the wall y+ is seen in the results as a SURFACE parameter, there is no need to look at anythin…

ah ok cause im looking at the symmetry plane on my model and trying to see the progressively thicker boundary layer size in relation to the Y+ mapping. Is this unimportant to have correct? i would think the BL needs to be accurate perpendicular to the desired surface [image]

That is a slice type view showing volume mesh cells, not a surface mapping view… That rainbow does not exist, the only two values on that screen is the darkest red at the surface and 0 everywhere else…

ok so i should be analyzing this result and checking that most surfaces are at 30 [image]

YES that is correct :slight_smile: (20-800 for log law (wall function) use)

[image] dschroeder: Is this unimportant to have correct? There is nothing to see with regard to the y+ results parameter, anywhere in the volume mesh cells… so there is nothing that can be correct or incorrect in them except that their y+ results value will be 0…

ah ok, i think the only thing i need now is advice on the region refinements to reduce total cell size. then i feel confident that i can get some good meshes myself. any advice?

A good way to potentially get rid of some of the y+ <20 AND reduce cell count in that last y+ surface map (green and blue areas in your image), would be to set your target y+ HIGHER in the y+ calculators… That is why I suggested maybe 100 OR HIGHER for you…

ok i understand the relation between the Y+ value and its relation to needed surface refinement size. but wouldnt that give inaccurate results? i though it was critical to draw data at the lower Y+ levels and 100 would be to large a 1st layer size

SimScale CAE Forum

Optimizing mesh quality and Y+ layer formation on an FSAE car

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DaleKramer December 19, 2019, 12:54pm 70

YES that is correct (20-800 for log law (wall function) use)