example of a profile or airfoil polar following the Reynolds number and the incidence

the polar highlight the airfoils efficiency.

The databases provide the Cd(cx in french)and Cl(cz in french) of the foil . the ratio Cl/Cd is (called finesse in french) may go up 60. (eg with a wing of the lift force is 40 times higher than the drag force. Actualy the lift force will be a little bit different, because some losses of lift appends at the end of the wing.

study of a profile or airfoil polar allows to choose taking into account its ratio Cl/Cd

The polar hundreds of profile or airfoil are stored in databases such as the NACA

The polar profile or airfoil selected in the software MECAFLUX are redefined with each change of incidence and the number of Reynolds calculated .