Swept-forward wing with swivel part of outer wing panels

FIELD: aeronautical engineering.

SUBSTANCE: each outer panel of proposed wing includes wing extension with sweep-back leading edge, root section with swept-forward leading edge and trailing edge; swivel part of wing outer panel is articulated with this section relative to vertical axis of flying vehicle; it may be turned backward in way of flow so that sweep angle of leading edge may change from initial swept-forward to swept-back magnitudes.

EFFECT: increased critical velocity of aero-elastic divergence.

2 dwg

The invention relates to aircraft and particularly to a wing with a variable sweep angle, and can be used in the design of supersonic aircraft, aircraft short or vertical takeoff and landing.

Wing reverse sweep (KOS) contains the center section and the console, the deviated nose of the aircraft. This wing is characterized by the fact that he had the angle sweep χ on the front edge of the console is smaller and the rear edge more than the straight wing. KOS has a number of advantages. It carrier is the root of the wing, where with increasing angles of attack, the local value of lift coefficient with_uabefore reaches the maximum value. Consequently, disruption of the flow begins before the root portion of KOS, which does not result in the loss of transverse controllability of the aircraft, since the area of the breakdown does not capture the ailerons. This increases safety and allows supersonic aircraft to use high angles of attack, increasing their maneuvering capabilities[1, 2, 3, 4]. The center section of KOS is located behind the center of mass of the aircraft, which is on passenger aircraft does not interfere with placement in the fuselage of the passenger compartment and cargo compartment [5, 6]. Shifting the center of mass of the aircraft forward, KOS facilitates its weight layout. When placed on KOS enabled the residents with thrust vectoring can be shifted forward of the point of application of resultant thrust and coordinate position of the center of gravity, the focus of the center rod and the chassis of the plane to provide a vertical take-off and landing. With easier satisfied the requirement of rule space, which can reduce the wave drag at transonic flight speeds and lower value of the required thrust for such a flight [7, 8].

Also known tselnopovorotnogo KOS, characterized by the fact that each console is hinged root part on the center wing or the fuselage of the aircraft. The control signals KOS turning the console can take position from perpendicular to the longitudinal axis of the aircraft (χ=0°) to parallel (χ=-90°) [9]. At small angle sweep χ improved load-bearing properties of the wing at low flight speeds, with high values of χ reduces drag at supersonic flight speeds. As a result, the plane becomes multimode, has a good take-off and landing characteristics, high maneuverability and high aerodynamic quality on cruise mode. It is also known the use of tselnopovorotnogo KOS in the design of a manned lander spacecraft [10].

Known plane containing the wing, made from portions of the forward and backward sweep, and plots the reverse sweep is executed swing relative to the positive horizontal axis of the aircraft so the aircraft acquires the properties of a classical plane or a plane with KOS depending on the mode and flight conditions [11]. The disadvantages of this wing are as follows. If airfoils sections forward and reverse sweep does not have the diamond shape, the flow around the wing flow is not effective due to the inability of the pair of profiles fixed and rotary wing sections. Low reliability because failure in the flight control system turn the plot of the reverse sweep, he can take a vertical position, which will lead to an emergency situation.

As a prototype of the invention selected wing detachable cockpit console which consist of two parts, pivotally connected about a vertical axis, while the root part of the consoles pivotally mounted on cab design also relative to the vertical axis of the aircraft. In the folded position the console is turned back to form the top and front edge of deltoid main wing aircraft. In the case of separation of the cab from the aircraft both parts of the console are rotated forward flow and function planning wing backward sweep [12].

Factor hindering the achievement of specified following technical result when using the years of KOS, including rotary, are its small critical speed aeroelastic divergence, which requires additional cost mass to increase strength and rigidity of KOS. The use of composite materials with a certain orientation of the fibers in the construction of the plating KOS allows you to increase the critical speed aeroelastic divergence, however, does not solve the problem, because until you create a versatile material, working effectively in the whole range of flight speeds. For this reason, the terminated program works by American aircraft X-29 and Russian aircraft s-37 "Berkut" [13, 14].

The invention and the technical effect of the invention is to increase the critical speed aeroelastic divergence of KOS.

This is achieved by the fact that in the famous KOS console which consist of two parts, pivotally connected about a vertical axis of the aircraft, according to the invention the root of the console is made with the influx straight sweep in front of the ball, rigidly attached to the Central wing or fuselage of the aircraft, and the rotary part can be rotated back through the thread so that the sweep angle on its front edge may vary from the original negative to positive values.

The invention is aasnaes drawings, where presented: figure 1 - view of the aircraft with the declared KOS with the rotary part of the console; figure 2 is a variant of the structural force schemes root of the console (in the limit section).

KOS with the rotary part of the consoles can be used as a light maneuverable and heavy supersonic aircraft. In the example embodiment of the invention used scheme of the aircraft in the form of an integral three-pronged layout, similar to the plane s-37 "Berkut" [14]. The plane (figure 1) contains a fuselage 1 with the root influx 2, wing-back sweep, front horizontal 3 and the tail 4 tail, war of the vertical tail 5, twin-engine power unit 6, the cockpit with the canopy 7, air intakes, chassis (not shown).

Declared wing aircraft has a complex shape in plan. It consists of root nodules 8 with positive sweep along the front edge, the root portion of consoles 9 with a reverse sweep on the front and rear edges, a rotary part of the consoles (pchk) 10. Root nodules 8 wing rigidly attached to the root influx 2 of the fuselage 1. The root of the console 9 and pchk 10 are connected pivotally about a vertical axis of the plane with the pivot point 11 so that when you turn the pchk 10 her tail in the area of the side rib is inserted into the root part of the console 9./p>

Geometric shape, the aspect ratio of the wing, their structural force schemes are defined and calculated according to certain rules [e.g. 1] in accordance with the purpose and flight tactical characteristics of the aircraft. In a preferred embodiment, the sweep angle of the leading edge root of the console 9 and pchk 10 in netcontrol position and is minus 13-18 degrees. In the deflected position b, the sweep angle of the leading edge pchk 10 is in the range from minus 13-18 to plus 30-35 degrees, i.e. the wing may have areas with backward and forward sweep. The ratio of the amplitude of the swing of the console to the wingspan is 0,6-0,65.

The root of the console 9 is executed on dvukhlineinoi scheme with a free internal volume between them to place in it the tail pchk 10, with the main spar 12, is placed in the forward part of the console, and the side member 13 placed at the tail may have in cross section a semi-oval shape (figure 2). Pchk 10 may have a decompression scheme with two spars and fuel tanks-compartments. Hinge 11 is located on the main spars of the root of the console 9 and pchk 10 at a distance of about 0.25 chords, respectively, end and side sections of these parts. Turn pchk 10 may be electro - or hydromechanic the sky actuator (not shown) along the guide 14 with the sealing device and fixing in position. To reduce the weight of the wing covering 15 of its parts can be made in the form of panels made of composite materials. The wing mechanism includes slats, say no to socks, flaps and ailerons (to simplify the drawing is not shown).

KOS with the rotary part of the console is as follows. In flight at an angle of attack of 8-10 degrees on the leading edge of the root influx 8 is formed vortex, which, rasprostranenie above the upper surface of the root portion of the console 9, reduces the area of separation of flow and prevents cross flow on the wing with increasing angle of attack. This results in an additional lift force decreases resistance and ensures high stability and controllability of the aircraft at high angles of attack. However, as the speed of flight increases the risk of aeroelastic divergence KOS arising in consequence of the fact that when bending this wing is twisted to increase the angle of attack, contributing to the appearance of an additional lifting force on the wing, which increases its bending, which further increases the angle of attack, etc. until the destruction of the wing. To prevent this phenomenon pchk 10 is rotated back through the thread on the calculated angles of sweep on its leading edge in the range from minus 13-18 degrees to plus 30-35 degrees. When power is in the area of direct and positive sweep pchk 10 Flexural will be tied to the decrease of angle of attack and thereby to compensate for the spin root of the console 9 to increase the angle of attack. Thus the derivative of the lift coefficient angle of attack is significantly reduced, which removes the value of the critical speed aeroelastic divergence beyond the maximum flight speed of the aircraft.

The use of the invention allows to expand the modes of operation of the supersonic aircraft, different in design and purpose.

Sources of information

1. Zhytomyr g-I aircraft Design: a Textbook for students of aviation specialties. - 2nd ed., revised and enlarged extra - M.: Mashinostroenie, 1995, p.60, 128-130, 135.

2. US 4767083, 64 21/04, 244-12 .3, 1988.

3. EN 2180309, 64 30/00, 2002.

4. EN 2212359, 64 30/00, 2003.

5. US 4741497, 64 1/00, 244/117 R, 1988.

6. US 5114097, 64 1/00, 244/119, 1992.

7. EN 1816717, 64 p 29/00, 1993.

8. EN 1821421, 64 29/04, 1993.

9. US 5984231, 64 3/40, 244/46, 1999.

10. EP 0217507, 64 G 1/14, 1/62, 1987.

11. EN 2241636, 64 3/40, 2004.

12. US 3881671, 64 D 25/08, 244/140, 1975.

13. Military aviation. KN. 1, 2nd ed., Corr. - Mn.: LLC "Potpourri", str.

14. Journal Avia Panorama, November-December, 1997, p.28-29.

Wing reverse sweep with a rotary part of the consoles, characterized by the fact that each console consists of a root influx with positive sweep along the front edge, the root portion with a reverse sweep on the front and rear edges, which is articulated relative to the vertical axis of the aircraft with the United rotatable part of the console can be rotated back through the thread so the sweep angle on its front edge may vary from the original negative to positive values.