I know boeing and airbus use propietary airfoils, but is there a single naca airfoil that is fairly representative of what modern airliners use?
Modern airliners use supercritical wing profiles, which allow for transsonic airflow speeds over the upper wing surface.
The NACA-profile heyday was a lomg time ago, way before high subsonic jetliners were built. But according to this link there were 8-digit NACA-profiles which were supercritical:
NACA 8-Series: A final variation on the 6- and 7-Series methodology was the NACA 8-Series designed for flight at supercritical speeds. Like the earlier airfoils, the goal was to maximize the extent of laminar flow on the upper and lower surfaces independently.
The methodology on how to construct the 8-series is given further along in the article, along with a statement that pro’s and con’s of the series are unknown and that they are very seldomly used….