Layering for yPlus of less than 1

Using SimScale
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You can also check the following presentation from Wolfdynamics about meshing with snappyHexMesh:

http://www.wolfdynamics.com/wiki/meshing_OF_SHM.pdf

From slice 63 onwards, Guerrero deals with the layers generation in snappyHexMesh and how, if not all, most of the parameters influence the end result.

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Thanks! Much appreciated.

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Helo Dale, everything that you’ve done here was formulated by you or did you follow some references/articles/books?
May I do two questions to you:

1)Why do I have to get a square background mesh (and I understood that it would be a mesh with the same lenght in the x,y and z directions , each cell)?
2) Why in the calc of MFLV (max first layer volume) did you get the thickness^2 but not the RLEL6^2? Because in my head, if I have a square mesh, in the boundary I would have the RLEL6 in 2 directions and the thickness in the normal direction from the patch I want to make the layer.
So, I would have RLEL6^3 that would be bigger than RLEL6*(EWD^2), that I would call the MFLV.
3) Why did you define the MCV (minimum cell volume) as MFLV/1000?

Thank you for your post and hope to see your reply!

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Sorry for late reply, I was away from SimScaling for a while :wink:

  1. See Main Settings for Hex-dominant Parametric | SimScale

  2. Boundary layer cells are made of prism cells. Prism cells can be and are almost always (when used in BL’s) thin in one direction. Prism cells are very reliable at calculating CFD values for flow parallel to the thin faces. My MFLV calculation of (RLEL#) *(1st layer thickness)^2 takes this into account.

  3. Regarding why I chose to divide MFVL by 1000 to get MCV, “I determined that by real time watching the meshing log for the ‘Layer addition iteration 0’ meshing log location and making sure that not many cells less than my chosen MCV were being discarded from the layers.” Basically it was a guess based on some practical experience, not backed by some theory. If I divided by a much smaller number, I started to see more prism cells discarded…

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