RU2546048C1 - Method for stabilisation of flight of ram wing surface effect vehicle and ram wing surface effect vehicle implementing this method - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: ram wing surface effect vehicle contains a power plant, a fin assembly, a wing fitted with rear edge lift devices with the axis of rotation located along wing span, a power drive for lift devices movement, an alighting gear. Rear edge lift device contains a flap designed with a possibility of deflection by the power drive with reference to the axis of rotation both downwards, and upwards. Meanwhile kinematic connection of the power drive with the flap contains an elastic element. During stabilisation of ram wing surface effect vehicle flight regulate flight speeds within the whole range of heights of screen effect action. Meanwhile at increase of flight height, up to heights with weak manifestation of screen effect, the ram wing surface effect vehicle is accelerated and simultaneously the first centre-line camber of the airfoil is increased. At decrease of flight height down to the heights with strong manifestation of screen effect the speed of the ram wing surface effect vehicle is decreased, and simultaneously the size of the second centre-line camber of the airfoil centreline is increased.

EFFECT: ensuring compliance with the necessary condition of aperiodic stability at heights of both strong and weak manifestation of screen effect by means of regulation of the airfoil centreline.

6 cl, 13 dwg

Description

The group of inventions relates to methods of stabilizing the flight of an ekranoplane, and in particular to a method of stabilizing the flight of an ekranoplane at all altitudes of the manifestation of the screen effect and ekranoplanes for implementing this method. The group of inventions can be used to stabilize the flight of an ekranoplan both in the zone of strong and weak manifestations of the screen effect, in particular above a surface with a changing microrelief (wave surface with high scoring, ice fields with hummocks, tundra, during aviation chemical work, etc.), as well as when creating an ekranoplan that implements this method.

The prior art methods for stabilizing the flight of an ekranoplan at all altitudes of the manifestation of the screen effect, and ekranoplanes with stability at all altitudes of the manifestation of the screen effect, up to off-screen altitudes.

As shown in the article “Criteria for the longitudinal stability of ekranoplanes," the author R.D. Irodov, Scientific notes TsAGI, M .: TsAGI, T.1, No. 4, 1970, p.63 ... 72 [1], the necessary condition for ensuring the stability of flight in the area of the effect of the screen effect is the location of the aerodynamic focus in height Xfh in front of the aerodynamic focus on pitch angle Xfυ and the position of the aerodynamic focus on pitch angle Xfυ behind the center of mass Xcm of an ekranoplan:

where Mz is the pitch moment coefficient;

Cy is the coefficient of lift;

υ is the pitch angle;

h = N / B _A - the relative altitude of the ekranoplan;

In _A - the average aerodynamic (or geometric) chord of the winged wing;

Xfh = dMz / dCy at u = const - safety margin in height;

Хυf = dMz / dCy at h = H / B _A = const is the margin of stability along the pitch angle.

In the article "Computational study of the influence of profile parameters on its aerodynamic characteristics near the screen," the authors V.N. Arkhangelsk, S.I. Konovalov, V.G. Gadetsky, Transactions of TsAGI, vol. 2304, pp. 12-21, 1985, [2], it is shown that depending on the profile lift coefficient on the pitch angle while maintaining a constant height above the screen Cy (ϑ, h) at h = const, there are always such pitch angles ϑ * and the corresponding lifting force coefficients Cy * for which dCy / dh = 0. In this case, a discontinuity occurs in the dependence Xfh = f (ϑ) of the 2nd kind, since Xfh = dMz / dCy = (dMz / dh) / (dCy / dh) = ± ∞. At values ϑ≤ϑ *, Cy≤Cy * there is no stability in height, since dCy / dh≥0, and with a decrease in flight height, the wing does not “repel”, but “attracts” to the surface. According to [2], using the profile with S-shaped centerline at angles of pitch θ * θ <θ _SET has pitch angle range Δθ _TSIs (and coefficients of lift ΔSy _TSIs) at which is observed a necessary stability condition (1):

where υ _TSIs, Cy _UUST - pitch angle and the lift coefficient, corresponding to the coincidence of foci adjustment and the angle of pitch: Xfh = Xfυ.

The use in winged wings with a profile with an S-shaped middle line, as shown in the description of the invention of the Russian Federation No. 2118269, IPC B64C 3/14, B60V 1/08, publication date 08/27/1998, [3], allowed to expand the range of pitch angles Δϑ _TSI and lift coefficients ΔСy _TSI , under which the necessary stability condition (1) is provided during the flight of an ekranoplan in the entire range of heights of the manifestation of the screen effect. However, aperiodic stability at altitudes with a weak effect of the screen effect H = (0.4 ... 2.0) V _{A is} ensured for small pitch angles ϑ _UST and lift coefficients Сy _UST and, therefore, at high flight speeds and low aerodynamic quality . With external disturbances, altitude maneuvering, and piloting errors, there may be situations of an ekranoplan flight with pitch angles close in magnitude to ϑ *, and an ekranoplane loss of stability in height dCy / dh≥0. To prevent the loss of stability along the height, the ekranoplan must be equipped with an automatic control system, for example, an automatic damping system.

In the article "Some nonlinear effects in stability and control of wing-in-gound effect vehicles", by Staufenbiel R., "J. Aircraft", 1978, VIII, v.15, No. 8, pp. 541-544, [4 ], it is shown that when flying at altitudes with a weak manifestation of the screen effect H = (0.4 ... 2.0) B _A, to ensure aperiodic flight stability, it is necessary to use an automatic control system, in particular, a speed stabilization system.

In the description of the invention of the Russian Federation No. 2286268, IPC B60V 1/08, publication date 10/27/2006, [5], an ekranoplane containing a power unit, a wing equipped with a trailing edge mechanization with at least one axis of rotation along wing span, power driven to move mechanization and plumage. When the wing is made integral, consisting of a center section and consoles connected to it, with the ratios of the areas and position of the center section, consoles and horizontal tail specified in the description of the invention [5], stability is ensured when flying at altitude as with strong (H≤0.4B _A ), and weak Н = (0.4 ... 2.0) B _A manifestation of the screen effect, up to the heights of the absence of the screen effect (H> 2B _A ), i.e. aircraft operational modes of movement.

In the book “WIG. Features of theory and design ”, authors A.I. Maskalik, B.A. Kolyzaev, V.I. Zhukov, G.L. Radovitsky, D.N. Sinitsyn, L.K. Zagorulko, ed. St. Petersburg, Shipbuilding, 2000, [6], on pages 288, 289, Fig. 147, an example of a wing-wing control system for wing flaps is presented, containing a mechanism for locking the control levers of the wings in any position. Flap control (p.163 ... 166, Fig. 85, 86, [6]) is intended for takeoff and landing modes and maneuvering in height in the zone of strong influence of the screen effect. At the same time, in the book [6] there are no data on the stabilization of the ekranoplan when flying at altitudes with a weak manifestation of the screen effect H = (0.4 ... 2.0) B _A.

A method of stabilizing the flight of an ekranoplane containing a wing equipped with mechanization of the trailing edge, including adjusting the flight speed over the entire range of altitudes of the screen effect, proposed in article [4], is taken as the closest analogue of the object of the invention “method”. The disadvantage of this method is the need to use an automatic control system for flying at altitudes with a weak manifestation of the screen effect.

An ekranoplane, presented in the invention [5], comprising a power plant, feathering, a wing equipped with a trailing edge mechanization with at least one axis of rotation located along the wing span, an energy drive for moving the mechanization, capable of flying at all altitudes of the ekranoplan effect , up to aircraft, adopted for the closest analogue of the ekranoplan, which implements the claimed method.

The technical task to be solved by the group of inventions is to provide the necessary conditions for the aperiodic stability of the ekranoplan when flying at altitudes with both strong, H <0.4B _A , and weak, H = (0.4 ... 2.0) V _A , a manifestation of the screen effect.

The technical result in terms of the method of stabilizing the ekranoplan is to determine the conditions for controlling the ekranoplan, ensuring the fulfillment of the necessary conditions for aperiodic stability at heights of both strong and weak manifestations of the screen effect.

The technical result in terms of the object of the invention “device” is to ensure that the necessary conditions of aperiodic stability are met at heights of both strong and weak manifestations of the screen effect by adjusting the midline of the wing profile.

The essence of the group of inventions is as follows.

The method of stabilizing the flight of an ekranoplane containing a wing equipped with mechanization of the trailing edge, as in the closest analogue [4], involves controlling the flight speed over the entire range of altitudes of the screen effect, but unlike the closest analogue [4], with increasing flight height up to altitudes with a weak manifestation of the screen effect, the ekranoplan accelerates and simultaneously increases the value of the first relative concavity of the midline of the wing profile, and when the altitude is reduced to altitudes with a strong manifestation of annogo effect speed WIG is reduced and simultaneously decrease a second magnitude of relative concavity midline airfoil.

The method is characterized in that the first relative concavity of the midline of the wing profile is changed by deflecting the wing flap down, and the value of the second relative concavity of the midline of the wing profile of the wing is changed by deflecting the wing flap up.

The ekranoplan, as in the closest analogue [5], contains a power plant, tail, wing, equipped with mechanization of the trailing edge with at least one axis of rotation located along the span of the wing, with an electric drive to move the mechanization of the trailing edge, but unlike the closest analogue [5], the mechanization of the trailing edge of the wing contains a flap configured to deflect the energy drive relative to the axis of rotation both down and up, and the kinematic connection of the power drive with the flap contains an elastic element.

Wing is characterized by the fact that the flap is made two-link, each of the links of the flap is made to deflect both down and up, and the kinematic connection of the power drive with the flap of the links contains an elastic element.

Wing is characterized by the fact that in the longitudinal section the contour of the lower surface of the longitudinal section of the flap is made in the form of a curve with a radius of curvature equal to 0.5 ... 4.5 chords of the wing and a center of curvature located above the upper surface of the wing.

Wing is characterized by the fact that the wing is made up of a center wing and consoles, the center wing is made with a large chord of the wing and is equipped with a flap.

The group of inventions is illustrated by drawings.

Figure 1 shows the profile of the winged wing.

Figure 2 shows the dependence of the pitch angle of the ekranoplan υ *, υ _ust as a function of height above the screen.

Figure 3 shows the lift coefficient WIG Cy *, Cy _SET on the height above the screen.

Figure 4 shows the dependence of the pitch angle υ * on the relative concavity of the winged wing profile.

Figure 5 presents a graph of the change in the position of the aerodynamic focus along the pitch angle from the concavity of the winged wing profile x _fϑ (f ₂ ).

Figure 6 presents a graph of the change in the position of the aerodynamic focus in height from the concavity of the wing profile x _fh (f ₂ ).

Figure 7 presents a graph of the variation in the separation of aerodynamic foci from the concavity of the wing profile of the winged aircraft Xfϑh (f ₂ ).

On Fig shows an example of the dependence of the relative concavity of the wing on the angle of deviation of the wing flap.

Figure 9 shows the ekranoplan when viewed in plan.

Figure 10 is a section aa in Figure 9 of a single link flap deflected downward.

Figure 11 is a section aa in figure 9 of a single link flap, tilted up.

On Fig given section BB in Fig.9 two-link flap, tilted down.

On Fig given section BB in Fig.9 two-link flap, tilted up.

The invention is as follows.

The stabilization of the flight of an ekranoplan without an automatic control system during climb and transition from altitude with a strong manifestation of the screen effect H <0.4B _A to the altitude zone with a weak manifestation of the screen effect H = (0.4 ... 2.0) B _A can only be ensured when the necessary aperiodic stability condition (1) is satisfied, namely, the location of the aerodynamic focus in height in front of the aerodynamic focus in pitch angle.

The parameters of the wing profile are shown in figure 1. As shown in FIGS. 2, 3 (and in the description of the invention [3]), as the distance from the screen increases, the critical pitch angles υ * and the corresponding lift coefficient Cy * decrease in magnitude, and the values υ _CCT and the corresponding coefficients Сy _CCT also decrease in the zone of strong manifestation of the screen effect, and at high altitudes the intensity of their change decreases. As a result, bands Δυ _{SET SET} ΔSy increase somewhat. However, the coefficients Сy _ССТ have small values and low corresponding aerodynamic quality values of ekranoplanes, in connection with which the implementation of such flight modes is possible only with a high thrust-weight ratio of ekranoplan.

An increase in the maximum relative concavity f _{1 of the} midline 1 of the profile, equal to the chord of the profile of the distance F ₁ to the chord 2 connecting the nose 3 and the tail of the profile, f ₁ = F ₁ / B _{A of} FIG. 1), leads to a decrease (increase in module) pitch angles υ * (FIG. 4) while maintaining small values of the corresponding Cy * coefficients.

As is known from the expression: Cy = (dCy / dυ) · (υ-υ ₀ ), where υ ₀ = -2f ₁ is the pitch angle at Cy = 0, with increasing positive concavity f _1, the pitch angle υ ₀ decreases, and the coefficient the lifting force of the profile (and wing) Cy for a given value of υ = υ _ust increases. Υ _TSIs pitch angle decreases to a lesser extent than the increased lift coefficient Cy _TSIs = (dCy / dυ) * ( υ _TSIs -υ ₀₎ for increasing the first relative concavity f _1, which provides a range extension sustainable lift coefficient ΔSy _TSIs, under which the necessary stability condition (1) is satisfied.

Computational and experimental studies have shown that the value of the second concavity f _{2 of} the wing profile with an S-shaped middle line with a small change (practically maintaining) the position of the aerodynamic focus along the pitch angle x _fυ (3), as shown in Fig. 5, affects the aerodynamic displacement focus height x _fh (2) towards the toe 3 profile (Fig.6). This is due to the fact that the lower surface of the wing, which forms the S-shaped center line 1, creates conditions for the implementation of the Venturi effect, in which, as a result of the acceleration of the flow in the region of the wing tail, the center of pressure on the lower surface moves toward the leading edge of the wing. In this case, the spacing of the aerodynamic foci Xfϑh, as shown in Fig. 7, increases, which ensures the fulfillment of the necessary stability condition (1) and stabilization of the ekranoplan flight without an automatic control system.

Thus, for a stable flight, it is necessary to accelerate the ekranoplane and simultaneously increase the positive concavity f _{1 of the} midline 1 of the wing profile during the transition from heights with strong (H <0.4B _A ) to heights with weak H = (0.5 ... 2.0) B _{A by the} manifestation of the screen effect, and vice versa, when moving from flight altitudes from low to high with a strong manifestation of the screen effect, the flight speed of the winged wing is reduced while the second concavity f _{2 of the} S-shaped center line 1 of the winged wing is reduced.

The presented method of stabilizing an ekranoplan on all ranges of altitudes of a screen flight can be implemented by changing the curvature of the midline of the wing profile of an ekranoplan when controlling flaps (Fig. 8) to control the concavity f ₁ ; f ₂ and / or slats (for adjusting the concavity f ₁ ). But to change the positive curvature of the profile, the flap deviation (Fig. 1) is sufficient for a distance not exceeding the thickness of the profile, which is significantly less than when the flap is deflected during take-off, landing, and when the altitude of the winged wing is controlled. In addition, the concavity values f ₁ , f ₂ are of great importance for the "regulation" of the boundaries of the stability corridor υ * ... υ _СУТ and Cy * ... Сy _СУТ . Therefore, to obtain the greatest effect when implementing the method of stabilizing the flight of an ekranoplan, a mechanization drive is needed that provides small movements of the trailing edge of the wing both down and up and fixes their position.

An example of an ekranoplan with such a mechanization that implements this stabilization method is presented in the object of the invention “device”.

The ekranoplan, made in the preferred embodiment of the group of inventions according to the “composite wing” scheme, contains a central wing (center wing 5) and consoles 6 attached to it, a power unit 7, horizontal 8 and vertical 8 tail units, a takeoff and landing device, for example, floats 10, fuselage 11. The center section 5 is equipped with mechanization of the trailing edge, for example, flap 12 (Fig.9).

The flap 12 is expediently made gapless, the deflection of the flap relative to the axis 13, both down and up, is provided by an electric drive 14, for example, a hydraulic cylinder, an electromechanism, etc., while fixing the intermediate positions of the flap 12 (Fig. 10, 11). In the kinematic connection of the actuator 14 with the flap 12 included an elastic link 15, for example, hydraulic, pneumatic, etc. shock absorber. The actuator 14 can be actuated either by the pilot or be involved in the control system, for example, receiving control signals from the pitch angle and pitch-hole flight sensors (not shown in Fig.).

The flap 12 can be performed gapless two-link (Fig.12, 13). The first link 16 of the flap 12 is connected to the wing 5 by means of an actuator 14 containing an elastic link 15, and is configured to deflect about the axis 13 both down and up. The second link 17 of the flap 12 is connected to the first link 16 by means of an electric drive 18, which deflects it both down and up relative to the first link 16 about the axis 19. In the kinematic connection of the power drive 18 with the second link 17 is included an elastic link 20, for example, hydraulic, pneumatic and etc. shock absorber.

In a preferred embodiment, the lower surface 21 of the flap 12, including the two-link, it is advisable to perform with a curved contour in the form of an arc in longitudinal section, while the radius of curvature R is (0.5 ... 4.5) V _A , and the axis of the arc is located above the upper surface of the wing 5. The flap 12 is also advisable to perform divided into a number of sections on the span of the wing 5 (Fig.9).

The invention is implemented as follows.

When flying an ekranoplane, it becomes necessary to change the altitude (for example, to fly over obstacles in height, the appearance of high waves, etc.), including to perform an ekranoplan flight at altitudes with a weak manifestation of the screen effect.

When moving to a flight altitude of H = (0.4 ... 2.0) V _A , which goes beyond the zone of strong influence of the screen effect H <0.4B _A , it is necessary to ensure the fulfillment of stability conditions (1). In order to expand the range of pitch angles Δϑ _UST and lift coefficients ΔСy _UST , in which the necessary condition of aperiodic stability (1) is fulfilled, increase the flight speed of the winged aircraft and increase the first relative concavity f _{1 of the} midline 1 of the wing profile 5. To do this, reject the energy drive 14 flap 12 down. When performing a cruising flight mode at a selected altitude with a weak manifestation of the screen effect N = (0.4 ... 2.0) B _{A, the} position of the flap 12 is fixed in the intermediate position, ensuring the fulfillment of the necessary conditions for aperiodic stability (1).

When approaching the screen from heights with weak H = (0.4 ... 2.0) B _A to heights with a strong manifestation of the screen effect H <0.4B _{A, the} speed of the ekranoplan decreases and at the same time decreases (increases the module) the value of the second concavity f ₂ average line 1 of the profile of the wing 5 by deflecting the flap 12 with the actuator 14 relative to the axis 13 up. At the same time, as shown in Fig.6, the aerodynamic focus in height moves forward (towards the toe 3 of the profile, Fig.1) and the spacing of the aerodynamic foci increases (Fig.7). This ensures the fulfillment of the necessary conditions for aperiodic stability. Moreover, adjusting the position of the aerodynamic focus along the height Xfh by changing the second relative concavity f ₂ , for example, when the flap 12 is deflected, Fig. 8, makes it possible to combine the positions of the aerodynamic focus in height with the center of mass Xfh = Хцм, which significantly improves stability and controllability ekranoplan at altitudes with a strong influence of the screen effect in a wide range of pitch angles ϑ, coefficients Cy and the corresponding ekranoplan flight speeds.

The execution of the flap 12 multilink, for example two-link (Fig, 13), the deviation of each of the links 16, 17 provides a smoother change in the lower 21 and upper surface of the flap 12 (and the midline 1 of the wing profile 12). This contributes to better regulation of the relative concavities and, in addition, to a decrease in the aerodynamic losses in the zones of flow interaction with the transition of the surfaces of the flap links, especially when the flap links 16, 17 deviate upward.

Thus, a change in the relative concavity of the midline 1 of the wing profile 5 by deflecting the flap 12 down and up provides an extension of the range of pitch angles Δϑ _UST = ϑ _UST -ϑ * and lift coefficients ΔСy _UST = Cy _UST -Cy * in the entire range of heights of manifestations of the screen effect Н≤2B _A , and, therefore, is a new property of the flap and winged wing as a whole in comparison with the examples of the execution of wing flaps of the winged wing wing known from the prior art.

The inclusion in the kinematic connection of the energy drive 14 with the flap 12 of the elastic link 15 provides the deflection of the flaps when they meet with obstruction in flights at low altitudes. The implementation of the bottom surface 21 of the flap 12, including a two-link, with a curved contour in longitudinal section, with an arc radius R = (0.5 ... 4.5) B _A , provides the formation of an S-shaped center line 1 profile, which extends the range of angles pitch Δϑ _UST and lift coefficients ΔСy _UST , and, therefore, reduces the deflection angles of the flaps 12 when adjusting the relative concavities of the wing profile 5.

The features included in the claims form a set of interconnected features necessary and sufficient for the implementation of a group of inventions. In the presented group of inventions, the unity of inventions is ensured, since the solution of the same technical problem is achieved with the achievement of the same technical result. The combination of features shown in the subject matter of the invention “device” is sufficient to implement the claimed method.

To implement the group of inventions, there is sufficient research and development and technological potential at the enterprises of the aviation and ship industry. The group of inventions meets the condition of patentability "industrial applicability".

LIST OF POSITIONS AND DESIGNATIONS

1 - the midline of the wing profile;

2 - profile chord;

3 - toe profile;

4 - tail profile;

5 - the center section of the composite wing;

6 - console composite wing;

7 - powerplant engine;

8 - horizontal plumage;

9 - vertical plumage;

10 - floats;

11 - the fuselage;

12 - flap;

13 - axis of rotation of the flap 12;

14 - power flap 12;

15 - elastic link;

16 - the first link of the flap 12;

17 - the second link of the flap 12;

18 - power drive of the second link 17 of the flap 12;

19 - the axis of rotation of the second link 17 of the flap 12;

20 - elastic link drive the second link 17 of the flap 12;

21 - curved lower surface of the flap 12.

Xfh = Xцм-dMz / dCy at υ = const - aerodynamic focus in height;

Xfυ = Xcm-dMz / dCy at h = Н / В _А = const - aerodynamic focus in pitch angle;

Mz is the pitch moment coefficient;

Cy is the coefficient of lift;

υ is the pitch angle;

h = N / B _A - the relative altitude of the ekranoplan;

In _A - the average aerodynamic (or geometric) chord of the winged wing;

f ₁ = F ₁ / B _A is the first relative concavity of the winged wing profile;

f ₂ = F ₂ / B _A is the second relative concavity of the winged wing profile

x _fh = dMz / dCy at υ = const - safety margin in height;

x _fυ = dMz / dCy at h = H / B _A = const is the margin of stability along the pitch angle;

ϑ * is the pitch angle at which dCy / dh = 0;

Cy * is the lift coefficient at which dCy / dh = 0;

ϑ _SET - pitch angle at Xfh = Xfυ;

Cy _TSIs - lift coefficient at Xfh = Xfυ.

Claims (6)

1. A method of stabilizing the flight of an ekranoplane containing a wing equipped with mechanization of the trailing edge, including controlling the flight speed over the entire range of altitudes of the effect of the screen effect, characterized in that with increasing flight altitude, up to altitudes with a weak manifestation of the screen effect, the ekranoplan is accelerated and simultaneously increased the first relative concavity of the midline of the wing profile, and when the flight altitude is reduced to altitudes with a strong manifestation of the screen effect, the speed of the ekranoplan is reduced and simultaneously reduce the value of the second relative concavity of the midline of the wing profile. 2. The method according to claim 1, characterized in that the first relative concavity of the midline of the wing profile is changed by deflecting the wing flap down, and the value of the second relative concavity of the midline of the wing profile is changed by deflecting the wing flap up. 3. Wing, comprising a power plant, feathering, wing, equipped with mechanization of the trailing edge with at least one axis of rotation located along the span of the wing, an energy drive for moving mechanization, takeoff and landing device, characterized in that the mechanization of the trailing edge of the wing contains a flap configured to be deflected by the power drive relative to the axis of rotation both down and up, and the kinematic connection of the power drive with the flap comprises an elastic element. 4. Wing according to claim 3, characterized in that the flap is made two-link, each of the links of the flap is made to deflect both down and up, and the kinematic connection of the power drive with the flap contains an elastic element. 5. Wing according to claim 3 or 4, characterized in that in the longitudinal section the contour of the lower surface of the longitudinal section of the flap is made in the form of a curve with a radius of curvature equal to 0.5 ... 4.5 wing chords and a center of curvature located above the upper surface wings. 6. Wing according to claim 3 or 4, characterized in that the wing is made up of a center wing and consoles, the center wing is made with a large chord of the wing and is equipped with a flap.

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