초록

The swept extreme tip edge of a helicopter rotor blade incorporates blade droop to reduce aerodynamic pitching moments caused by spanwise flow encountered in the fore and aft sectors of a rotor rotational disc during forward flight of a helicopter on which the blade is fitted.

대표청구항 ▼

A helicopter rotor blade having a root end adapted for attachment to a rotor head, a central portion extending from the root end and being of aerofoil section having leading and trailing edges, a cord dimension and a feathering axis, and a swept tip at the end of the central portion opposite the roo

A helicopter rotor blade having a root end adapted for attachment to a rotor head, a central portion extending from the root end and being of aerofoil section having leading and trailing edges, a cord dimension and a feathering axis, and a swept tip at the end of the central portion opposite the root end and defining a blade space, the swept tip including a swept extreme tip edge having a sweep angle between 55 and 85 degrees from the feathering axis, wherein the swept extreme tip edge droops downwardly to minimize an undesirable effect of spanwise airflow encountered in the fore and aft sectors of a rotor rotational disc during forward flight of a helicopter in which the blade is fitted by reducing the strength of local chordwise bound vortices over the swept extreme tip edge and resulting undesirable aerodynamic pitching moments.