Problems in Boundary Layer Generation for Aerodynamic Analysis

Hi, I am trying to mesh my design for the CFD simulation of a Formula 1 front wing. But even though I am using the parametric hex dominant mode, I seem to encounter a problem where my boundary layers are not being generated. I tried using multiple methods and even decreased the number of boundary layers. But when I conduct a mesh inspection for the boundary layer, I see that the layers have completely collapsed the mesh has not generated properly.

This is how the layers look like for the entire mid-span of the wing. Ideally there should have been 5 layers from the airfoils, but it seems to be that the layers have been deleted. I am attaching screenshots of my mesh generation settings for better information.

I have tried to clean my geometry and whenever I run an interference check, I don’t seem to have any issues with the geometry itself, so it is a clean geometry. For the bounding box, I am using a 5x chord length upstream, 15x downstream, and 5x chord length in Y and Z direction. I have tried following each and every tutorial step by step according to the multiple posts in the fourm but for some reason I can’t seem to create a better mesh than this with the accurately generated boundary layers.

If someone could create a proper mesh with the boundary layers and send me screenshot helping me out with the parameters that I need to address or tweak, it will be very helpful for my project. I genuinely want to understand why is my generation going wrong even though I am following the same steps as everyone.

Hi,

There’s a very lengthy and thorough discussion on this topic here for external aerodynamics: Optimizing mesh quality and Y+ layer formation on an FSAE car

Cheers

Hi,

I went through the entire thread, and honestly, the discussion went far too technical for me to imagine or understand. I really just want someone to dumb it down slightly for me, because even while following the given steps in the thread, I am not able to generate the perfect prism layers. So at the end of the day, I just want to know where I did the mistake in this mesh generation and create a good mesh with the prism layers.

Thanks

With the hex-dominant meshing tool you really need to be careful about the boundary layer > surface mesh transition. If the boundary layers are too small and you suddenly jump to a much larger cell in the surface mesh, it’s easy to get layers deleted.

The standard meshing tool is more consistent in inflating and maintaining boundary layers, so perhaps you could give it a try?