Spacing near the wall
 

Hi everyone,
I'm working with DLR F6 Geometry. My mesh is quite fine with high spacing.But when I decrease to very low spacing for y+<5, the elements near the wall become negative volume and be corrupted.
I tried to change Projection limit, turn on Project Bspline, some places was fixed but not all.
So I want you guys give me some advice to handle this problem :(
Thanks a lot