Meshing Issue for Wind Study

I am working with butterfly, and i recently tried to have a better idea on the meshing proccess. The result given by the program seems strange (the horizontal grid looks good, but the vertical separation looks stange)
Can you tell me if for you it looks normal, and if not, can you give me an idea to correct it?

GH: (707.5 KB)

Thank you!

hi @HENIN_Valentin

The grading components works well on the x and y plane, I’ve always read the output grad_xyz and input it manually as in the screen capture. The z component needs to be adjusted manually. For wind around buildings at the same height (without terrain variation), I usually split the wind tunnel in 2 portions for grading.
This depends greatly on the size of your wind tunnel and your geometry and your areas of interest.

Just to help you understand my screen capture for the Z grading:
percentage lengths : division happens at 25% of the height of the wind tunnel.
percentage cells : 45% of cells at building height (for 25% of the Z length), 55% of cells above buildings (for 55% of the remaining Z length)
expansion ratio: I leave the ones at building height 1:1 ratio and the ones above to gradually distort for a smooth gradient 4:1.

Hope this helps.


Hi @OlivierDambron

First of all, sorry for the long time without answering, but i was working on other aspects of my project, so GH on standby.

I have tried your technique, and it worked pretty well!

The only issue is that we have to copy manually the values for ‘x’ and ‘y’ (or have I missed something?)
I will try to find a solution to this (but not right now, the wind/energy study will probably restart during/after November). If I find any solution to automate it, I will give you updates on this post (maybe it could also be useful for you).

Another point that I have recently discovered is the ‘castellated mesh’ (screenshot taken with the old script, so without the corrected mesh grading).

I did not succeed to change this, even when I was trying other parameters. If you have any idea to obtain a mesh that fit better to the surface, I am open to any solution (maybe just increase the meshing grid, playing with the new grading parameters, but I am afraid that it will lead to higher calculation time).

Thanks for everything !

HENIN Valentin