[JoSchl]

Hello,

I read about the Yplus value and its meaning, but now I have no idea how I can calculate my first layer thickness which I have to set for my meshing.
I am working with Ansys AIM and doing a steady fluid flow car simulation (Picture). I am using the SST turbulence model, so my y+ needs to be <1.
I already found the https://www.cfd-online.com/Tools/yplus.php calculator but I do not know the valuesof the "Boundary layer length".
So my question is, how I can estimate a value for the "boundary layer length". for the upper calculation. My windtunnel is 25*5*7[m] with symmetry, the car inside is 4.5*1.3[m].
Furthermore, which growth rate and maximum number of layers are recommended for such a simulation?

Thank you.