Patent ID: 6948906

Claim:
A rotor blade system with reduced blade-vortex interaction noise, comprising: at least one rotor blade coupled at one end thereof to a central hub and extending radially therefrom and terminating in a rotor blade tip face at another end of said at least one rotor blade opposite to said one end thereof, said at least one rotor blade having spaced apart upper and lower surfaces, leading and trailing edge portions at respective opposing joined edges of said upper and lower surfaces, and an interior volume of said at least one rotor blade defined and enveloped by said upper and lower surfaces, said leading and trailing edges, and said rotor blade tip face; and at least one tube member embedded into said at least one rotor blade in proximity to said another end thereof, said at least one tube member having an inlet located above said leading edge, an outlet located at said rotor blade tip face, and a tube member length extending between said inlet and outlet within said interior volume of said at least one rotor blade, wherein said at least one tube member being positioned within said at least one rotor blade such that a portion of incident flow is directed from said leading edge through said at least one tube member and is ejected from said rotor blade tip face whereby a tip vortex is detached from said rotor blade tip face and turbulent vortlets are introduced within a laminar core of a developing vortex for dissolving said laminar core and reducing blade-vortex interaction noise, said inlet being shaped and positioned to maximize attenuation of flow velocities within the vortex core.