You really want y+ of around 1 to capture the near wall effect, but also then need 15+ cells in the boundary layer region. Plus a sensible aspect ratio, good cell ortho quality and good streamwise resolution. That all adds up to a high cell count. There's a reason people modelling this sort of thing properly use a lot of parallel compute and cell counts in the 10's to 100's of millions.
You are navigating away from the AIS Discovery experience