| 摘要 |
Low-noise airfoils and methods of reducing noise. One embodiment provides an aerodynamic member that includes two body portions coupled to each other. The second body portion includes a plurality of airfoil members in a fixed relationship with each other. Optionally, the airfoil members may define an open end of the second body portion. In the alternative, the member can include a third body portion that has an airfoil shape and that is coupled to the second body portion opposite the first body portion. Preferably, the first portion, the airfoil members, and third portion are 12%, 8%, and 2% thickness/chord airfoils respectively. Further, the aerodynamic member may be a rotor blade on a tandem helicopter. Another embodiment provides a cambered airfoil with two coupled body portions one of which has air foil members. One of the body portions includes a slot there through with airfoil members on opposite sides of the slot.
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