Small wing of wingtip with adjustable angle of attack and wingtip of wing

Abstract

The invention relates to a small wing of a wingtip with an adjustable angle of attack and the wingtip of a wing, and belongs to the field of wing structures. The angle of attack of a low mach number ascending and descending stage of an existing small wing of the wingtip is not large enough, and when a taking-off and landing low-speed stage reaches a threshold angle of attack, the small wing stalls. The small wing is composed of one or two sheets, and is arranged on an end curve surface of the wingtip of the wing, a rotary shaft is located on the 1 / 4 chord line of the small wing or the slightlyforward position of the 1 / 4 chord line of the small wing, the rotary shaft is horizontal or nearly horizontal, and both sweepback, the rotary shaft is inserted from the end curve surface of the wingtip of the wing and supported on a bearing, a motor in the wingtip is used for reduction driving, and automatic deflection is carried out to enable the angle of attack to be adjustable, so that the value of the angle of attack of the small wing reaches to a comparatively large value in various stages. A drive torque of the small wing is small, and the component in the lift direction of an airplaneof aerodynamic force is large. Furthermore, a sheet of spanwise, sweepback, and fixedly-sheared wingtip is additionally arranged on the wingtip of the small wing. The small wing of the wingtip with the adjustable angle of attack and the wingtip of the wing is used for further reduce wing induced drag.

Description

technical field [0001] The invention relates to an aircraft winglet and a wingtip, in particular to an adjustable angle-of-attack winglet and a driving mechanism inside the wingtip, as well as a wingtip structure, which is suitable for subsonic aircraft. Background technique [0002] The complementary angle of the helix angle of the wing tip vortex at radius r is a linear function of the wing angle of attack α, which is kα. A winglet is placed in the wingtip flow field, assuming its chord length is infinitesimal, and it has little effect on the flow field at different angles of attack, for the convenience of the following discussion. Let the inclination angle or elevation angle of the vertical or horizontal winglet root chord relative to the wing tip chord be α 0 , then the angle of attack of the vertical winglet is: α y =kα+α 0 , the angle of attack of the horizontal winglet is: α z =kα+α+α 0 . When the angle of attack of the wing changes by Δα, the change of the angl...

AI Technical Summary

Problems solved by technology

Patent 1. has the following disadvantages: (1) the lift direction component of the aerodynamic force is small when the winglet is vertical; (2) the aerodynamic center of the winglet is far away from the rotating shaft, and a large driving torque is required when the winglet rotates

Patent 2. has the following disadvantages: (1) the lift direction component of the aerodynamic force is small, (2) the efficiency of the vertical winglets to weaken the tip vortex is lower than that of the horizontal winglets, (3) there is interference resistance

In addition, Patent 1. The winglet is vertical in the low speed section of takeoff and landing. Patent 2. The winglet is vertical. In addition to the longitudinal moment vector, when the winglet stalls in the crosswind section of the low speed section of takeoff and landing, the winglet will cause damage to Patent 1. Additional wing box and short shaft, Or for patent 2. The lateral moment vector of the long end of the L-shaped curved beam, because the radius of the aerodynamic center is large, the moment is large, and the structural strength and rigidity are low, which is unreasonable

In addition, the existing adjustable angle-of-attack winglets cannot use multiple winglets arranged front and back to improve drag reduction capabilities like the eagle.

The existing multi-piece fixed vertical winglets are 2 pieces up and down and 2 pieces parallel, because the front piece of the 2 piece front and back type will affect the rear piece when it stalls

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