Polar of an hydrodynamic aerodynamic profile according to the Reynolds number and incidence or attack angle
the polar highlights the profiles Lift/Drag ratio.
Databases provides the profiles Cl and Cd (Lift and Drag coefficients) the Lift/Drag ratio = Cl/ Cd ratio. ex: a wing with a Lift/Drag of 40, has lift 40 times higher than its drag.
the study of the polar of a profile, allows to select it considering its Lift/Drag ratio
Polar for hundreds of profiles are stored in databases such as the NACA airfoils database
Polar profiles, selected from the MECAFLUX standard software are reset each change of incidence (or attack angle), depending on the calculated Reynolds number.
The database profiles MECAFLUX Heliciel, allows you to create the new design patterns and memorize the performance under a wide range of Reynolds numbers to create propellers or wings: Interactive profiles polar database Heliciel: