JP3130698B2 - Wing shape of tailless aircraft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wing shape of an aircraft having no horizontal tail (hereinafter referred to as a tailless aircraft), and more particularly to a wing shape of a tailless aircraft having improved stall characteristics and stealth performance.

[0002]

2. Description of the Related Art In general, a forward wing tends to stall from the root of the wing (wing root). This causes a tip stalling (Tip Stall) at a high angle of attack, and the rudder works well at a high angle of attack. That is, it is known as an airfoil for obtaining good high angle of attack flight. In addition, the effective wing of the shock wave
It is also known that the airfoil has a larger angle than normal wings and provides good maneuverability at transonic speeds. For this reason, a tailless aircraft has been proposed in which the main wing is a forward wing and a control control surface is provided at the trailing edge of the main wing (Japanese Patent Laid-Open No. 59-733).
No. 96).

[0003] Such tailless aircraft generally have good high-angle-of-attack flight performance. However, during high-angle-of-attack flight, a stall occurs early in the wing root portion of the forward wing. It was difficult to maintain the attitude of the aircraft only on the surface.

On the other hand, a conventional forward wing aircraft is provided with a front wing (canard) in order to maintain the attitude of the aircraft at a high angle of attack, and cooperates with a control surface of a rear edge of the canard and a rear edge of a wing root portion of a main wing. The attitude of the aircraft was controlled by the work.

[0005]

However, providing canards, as in the above-mentioned conventional forward wing aircraft,
There was a problem that it was difficult to couple with the main wing during high-angle-of-attack flight, and an increase in the radar reflection area Radar Cross Section (RCS) due to an increase in extra wings (canards).

[0006] Here, the fact that the coupling is difficult means that it is difficult to control the control surface of the canard in consideration of the influence of aerodynamic interference between the canard, the airframe, and the main wing. In other words, when steering the canard during a high angle of attack flight, if the steering angle is small, the stall of the canard itself will occur and the rudder will not work, and also the movement of the center of gravity position, the change of the rudder angle of other rudder surfaces, etc. Since the steering angle of the canard is generally large because the change in the state of the aircraft requires a considerable change in the steering angle of the canard, control of the control surface of the canard during a high angle of attack flight is controlled by the canard and main wing induced by the steering. And the influence of strong and complicated aerodynamic interference of the aircraft must be taken into account, and it is difficult to control the steering angle appropriately.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional forward wing aircraft, and to provide a tailless wing aircraft that facilitates steering control during high-angle-of-attack flight and has good stall characteristics and stealth performance. It is to provide a wing shape.

[0008]

The wing shape of the tailless aircraft according to the present invention is such that a main wing having a leading edge kink is formed by integrally combining an inner wing including a rhombic wing and an outer wing of a forward wing. An elevon is provided at the trailing edge of the wing portion and an aileron is provided at the trailing edge of the outer wing portion. The advancing angle of the outer wing portion is 34 ° to 40 °, the leading edge angle of the inner wing portion is 68 ° to 78 °, and the span of the leading edge kink. The position is 35% to 56% of the exposed wing of the outer wing.

[0009]

According to the wing shape of the tailless aircraft according to the present invention, a main wing having a leading edge kink is formed by integrally combining an inner wing portion including a rhombic wing and an outer wing portion of a forward wing. The rear edge of the outer wing is provided with an elevon and the aileron is provided at the rear edge. By the combination of the rhombic wing and the forward wing, the separation of the root portion of the main wing is delayed by the effect of the stable separation eddy current from the leading edge of the rhombic wing, and the separation of the wing tip is delayed by the effect of the forward wing. By providing the elevon and the aileron at the inner wing trailing edge and the outer wing trailing edge, respectively, it is possible to secure the effect of the aileron and the elevon and roll damping for suppressing a violent roll up to a high angle of attack. Further, since there is no control surface such as a canard in the field where the main wing is blown up, there is no aerodynamic interference with the main wing due to the steering of the canard, and it is possible to obtain a wing of a tailless aircraft with easier steering control.

In addition, the wing shape of the tailless aircraft according to the present invention is improved in stealth performance by reducing the RCS and the unevenness of the body surface, as compared with the wing shape of a conventional forward wing aircraft having a canard. Can be.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a tailless aircraft having a wing shape according to the present invention. Tailless aircraft 1
Has a main wing 3 on both sides thereof, and a vertical tail 4 at an upper rear portion of the fuselage 2. The main wing 3 has an inner wing portion 6 including a rhombus wing 5 and an outer wing portion 7 composed of a forward wing. Outer wing 7 and inner wing 6
Is kinked at the point a. An elevon 8 is provided at a rear edge of the inner wing portion 6, and an aileron 9 is provided at a rear edge of the outer wing portion 7.

In this embodiment, the forward wing of the forward wing of the outer wing portion 7 (-
Λ _FSW ) is the swept position of the leading edge of the rhombic wing of the 40 ° inner wing 6 (Λ _s ) is the span position of the leading edge kink a 68 ° _LEKINK
Is set to 40% of the exposed wing of the wing 3.

The operation of the main wing 3 having the above configuration will be described below with reference to FIG.

FIG. 2 illustrates the state of a wing-shaped eddy current according to the present invention. As shown in FIG. 2 (a), the rhombus blade 5 generally generates a vortex from the leading edge, and the leading edge of the blade becomes a separation region. However, separation occurs at the root of the blade due to the effect of the leading edge separation vortex flowing down. Less likely to occur. On the other hand, in the forward wing 7, as shown in FIG. 2B, a separated vortex is generated from the tip of the wing, and this vortex flows backward at the blade root and the blade root becomes a separated area. In the part, peeling does not easily occur. The wing shape of the present invention is a combination of the rhombic wing and the forward wing,
As shown in FIG. 2C, the eddy current from the leading edge of the rhombic wing 5 and the eddy current from the tip of the forward wing 7 are parallel and cross the center of the span of the main wing 3. That is, only a part of the central portion of the main wing 3 becomes a separation area, and separation does not easily occur at both the blade root portion and the blade tip portion. In this peeled state, the elevon 8 provided on the trailing edge of the inner wing 6 and the aileron 9 (see FIG. 1) provided on the trailing edge of the outer wing 7 can still generate a lift, so that a high angle of attack flight The steering force can be maintained until time.

If the angle of attack is further increased with this wing shape,
As shown in FIG. 2D, separation occurs in a wide range of the inner wing 6 and the outer wing 7.

[0016] and the leading edge sweep angle lambda _s diamond blade of blade shape according to the present invention then, a forward angle 1-? _FSW forward wing limitations position η _'LEKINK the leading edge kink be described.

The main wing tailless aircraft according to the present invention include, but exerts its effect by delaying the release of the inner blade portion 6, before the edge sweep angle lambda _s is equal to or less than a predetermined value, the vortices in any angle of attack A breakdown phenomenon occurs in which the flow velocity sharply decreases and the lift decreases.

FIG. 3 shows a wind test result of a delta wing made of a thin plate. The horizontal axis represents the leading edge sweep angle lambda _s 3,
The vertical and horizontal directions indicate the angle of attack α _BD-TE that causes a vortex breakdown at the trailing edge of the wing.

For various leading edge receding angles Λ _s , the angle of attack α _BD-TE that causes vortex breakdown is plotted near line P in the figure. As it is clear from FIG. 3, the leading edge sweep angle lambda _s is the angle of attack to produce a breakdown of the vortex at 55 ° alpha
_BD-TE is almost 0 °. From the test results, the leading edge sweep angle lambda _s 55 ° the lower limit of lambda _s.

Further, in the main wing 3 of the present invention, the stall occurs early behind the leading edge kink a, so that the steering effect cannot be maintained unless the elevon 8 is provided inside the leading edge kink a. If the span position η ' _LEKINK of the leading edge kink a is made too _small , the steering volume of the elevon 8 becomes insufficient. In the tailless aircraft 1 of the above embodiment, the ratio of the control surface / wing root portion cord length is an average value of 0.11, but the maximum value of the control surface / wing root code ratio of the existing aircraft is 0.12. Η ′ _LEKINK in order to secure a sufficient control surface area in consideration of
= 0.35 is the lower limit of η ' _LEKINK .

The advance angle -Λ _FSW is determined from the effect of the forward wing, and in the present invention, the advance angle -Λ _FSW = 34 °
Is the lower limit of the advance angle-Λ _FSW .

Next, under the restrictions of the advancing angle −Λ _FSW (≧ 34 °), the leading edge receding angle _{ｓ s} (≧ 55 °), and the span position η ′ _LEKINK (≧ 0.35) of the leading edge kink, The range of the wing shape having good high angle of attack flight will be described.

[0023] Figure 4, the vertical axis angle of attack of the stripping zone at substantially the entire blade root, and the angle of attack as a stripping zone at the blade tip almost the entire area on the horizontal axis, the advancing angle 1-? _FSW, front edge sweep Combination of angle Λ _s , leading edge kink span position η ′ _LEKINK (−Λ _FSW , _{ｓ s} ,
η ′ _LEKINK ) is a graph in which the airfoil shape specified from the plot is plotted.

Theoretically, on the straight line X in FIG. 4 in which the angle of attack, which is the separation area in almost the entire area of the blade root, and the angle of attack, which is the separation area in almost the entire area of the blade tip, are steered to the highest angle of attack. Can be maintained. However, the advance angle-
Λ _FSW , leading edge swept angle Λ _s , leading edge kink span position η '
It has been found that the wing shape in which the limitation of _LEKINK and the separation that is practically well-balanced are the wing shape in the region A shown in FIG. Here, the area A is a point P1 including the lower limit of -Λ _FSW.
(34 °, 68 °, 042), the point P2 (40 °, 68 °, 0.56) including the upper limit of η ' _LEKING , and the point P3 (40 °, 68 °, 0. 42), Λ _s
Is an area roughly surrounded by a point P4 (40 °, 78 °, 0.42) including the upper limit value of.

In the final wind tunnel experiment, it was confirmed that the main wing 3 of the above embodiment can be put to practical use.

[0026]

As is clear from the above description, the wing shape of the tailless aircraft of the present invention is such that a main wing having a leading edge kink is constituted by combining an inner wing portion including a rhombus wing and an outer wing portion of a forward wing. The main wing is provided with an elevon at the trailing edge of the inner wing and an aileron at the trailing edge of the outer wing, so that the rhombic wing and forward wing function to maintain the effectiveness of elevon and aileron steering and roll damping up to a high angle of attack. Thus, it is possible to obtain a wing shape of a tailless aircraft excellent in high angle of flight.

In addition, since the steering force of the elevon is maintained during the flight at a high angle of attack, the canard which was conventionally required can be omitted, and the difficulty of coupling of the main wing and the canard during the flight at a high angle of attack can be avoided. Control becomes easier, and
Stealth performance can be improved by reducing the RCS.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a tailless aircraft having a wing shape according to the present invention.

FIG. 2 is a diagram illustrating a state of vortex separation of a wing shape of a tailless aircraft according to the present invention.

Figure 3 is a graph showing the angle α relationship _BD-TE resulting in breakdown of the leading edge separation vortices at the leading edge sweep angle lambda _s the wing trailing edge of the delta wing.

FIG. 4 is a graph showing a wing-shaped region where practically well-balanced separation occurs at a blade root portion and a blade tip portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tailless aircraft 3 Main wing 5 Diamond wing 6 Inner wing part 7 Outer wing part 8 Elevon 9 Aileron -Λ _FSW advance angle _{s s Leading} edge receding angle η ' _LEKINK Span position of leading edge kink

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B64C 3/00-3/16 B64C 39/00

Claims (1)

(57) [Claims] A wing having a leading edge kink (a) by integrally combining an inner wing (6) including a rhombus wing (5) and an outer wing (7) of a forward wing in a wing shape of a tailless aircraft. (3)
And an elevon (8) on the trailing edge of the inner wing portion of the main wing (3),
An aileron (9) is provided at the trailing edge of the outer wing, the advancing angle (−Λ _FSW ) of the forward wing of the outer wing (7) is 34 ° to 40 °, and the rhombus (5) of the inner wing (6) is before edge sweep angle (Λ _S) 68 °
To 78 °, the span position of the leading edge kink (a) (η '
_LEKINK ) 35% to 56% of the _exposed wing
Wing shape of tailless aircraft.