what defines a low Re number for airfoil flows?
 

How does one define a low Reynolds number airfoil flow? is 1 million considered low?

Cheerios Rif

Re: what defines a low Re number for airfoil flows
 

1e6 is possibly marginally low, but not much. Perhaps a meaningful definition is that low Re is where laminar separations start causing serious issues. So yes, < 1e6 would be a reasonable threshold.