US 6,161,800 AGranted

Pivoting spanwise-flow redirector for tiltrotor aircraft

AssigneeThe Boeing Company

InventorsJohn Liu, Michael A. McVeigh, Robert J. Mayer

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Abstract

A tiltrotor aircraft includes a spanwise-flow redirector having a pair of flow-redirection panels respectively mounted on the aircraft's mid-fuselage area for rotation about a panel pivot axis between a stowed position and a deployed position. In the stowed position, each panel is substantially flush with an adjacent surface of the mid-fuselage area. In the deployed position, each panel is raised into the path of one of the inbound spanwise flows generated by the aircraft's rotors during hover operation, whereupon each panel redirects the respective one of the inbound spanwise flows either forward or aft of the other inbound spanwise flow. In this manner, the deployed panels prevent stagnation of the inbound spanwise flow atop the mid-fuselage area while further serving to minimize re-ingestion of merged spanwise flow into the rotors, resulting in decreased airframe download forces, increased rotor thrust, and reduced noise levels during hover operation.

Claims21

Dependent claims

In a tiltrotor aircraft including a fuselage having a centerline axis, a pair of generally-oppositely-extending wings on the fuselage separated by a mid-fulselage area, and a driven rotor mounted on each wing for rotation between a forward-flight position and a hover position, and wherein the driven rotors in the hover position generate a first spanwise flow toward the mid-fuselage area over one of the wings and a second spanwise flow toward the mid-fuselage area over another of the wings, the improvement comprising a spanwise-flow redirector including:

at least one panel mounted on the aircraft for pivotal movement about a respective panel pivot axis between a first position and a second position, each panel pivot axis forming a respective first acute angle with a vertical reference plane containing the centerline axis of the fuselage;
wherein the first position is characterized in that the at least one panel is substantially flush with an adjacent surface of at least one of the group consisting of a wing and the mid-fuselage area;
and
wherein the second position is characterized in that the at least one panel projects above the adjacent surface of the at least one of the group consisting of the wing and the mid-fuselage area to substantially redirect the first spanwise flow generally forward of the second spanwise flow while substantially redirecting the second spanwise flow generally aft of the first spanwise flow.

1 more element

A flow redirector adapted for use in a tiltrotor aircraft, wherein the aircraft includes a fuselage having a centerline axis, a pair of generally-oppositely-extending wings on the fuselage separated by a mid-fuselage area, and a driven rotor mounted on each wing for rotation between a forward-flight position and a hover position, and wherein the driven rotors in the hover position generate a first spanwise flow toward the mid-fuselage area over one of the wings and a second spanwise flow toward the mid-fuselage area over another of the wings, the flow redirector comprising:

a first panel mounted on one of the fuselage and one wing for pivotal movement about a first panel pivot axis between a first position, wherein the first panel is substantially flush with at least one of the fuselage and an upper surface of the one wing, and a second position, wherein a surface of the first panel substantially redirects spanwise flow over the one wing generally forward of spanwise flow over the other wing;
a second panel mounted on one of the fuselage and the other wing for pivotal movement about a second panel pivot axis between a first position, wherein the second panel is substantially flush with at least one of the fuselage and an upper surface of the other wing, and a second position, wherein a surface of the second panel substantially redirects spanwise flow over the other wing generally aft of spanwise flow over the one wing;
and
wherein the first panel pivot axis forms a first acute angle with a vertical reference plane containing the centerline axis of the fuselage, and the second panel pivot axis forms a second acute angle with a vertical reference plane containing the centerline axis of the fuselage.

1 more element

Dependencies are inferred from the claim text.