RU2543431C1 - Self-stabilising wing-in-ground-effect plane - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: this plane features canard configuration and comprises fuselage, forplane, main tail wing, tail unit with rudder and engine with propulsor. Forplane is composed by front and rear bearing surfaces connected by central pylon. Front bearing surface is composed of the wing with sweep of 30-75 degrees in leading edge and zero sweep in trailing edge. Rear bearing surface is composed by the wing with zero sweep in leading edge and arc-shape trailing edge of negative sweep at zero pitch that has equal spacing from horizontal plane over its entire length. Front bearing surface in lengthwise direction is located ahead of rear bearing surface leading edge while in height rear bearing surface trailing edge is located under rear bearing surface leading edge.

EFFECT: better longitudinal stability at wind-wave effects.

2 dwg

Description

The present invention relates to the field of transport equipment, in particular to self-stabilizing ekranoplanes.

) и при малых ветроволновых возмущениях. Такой экраноплан можно назвать самостабилизирующимся (в данном случае в продольной плоскости движения) только в малом диапазоне эксплуатационных отстояний. Заметим, что под самостабилизацией понимается такое свойство экраноплана, когда после воздействия внешнего возмущения, при новом положении летательного аппарата, без вмешательства управления сохраняется необходимый запас устойчивости воздушного судна для компенсации всех внешних ветроволновых возмущений, допустимых для экранопланов этого класса мореходности.Known self-stabilizing ekranoplan ADP-05 "Orpheus" [A.S. No. 915372 USSR, IPC B60V 1/08, Self-stabilized ekranoplan according to the Utka scheme / Panchenkov A.N., Urizchenko V.Ya., Popov KB, etc. Applicant and patent holder Irkutsk computing center of the Siberian Branch of the USSR Academy of Sciences - No. 2895857; declared 04.19.80.], Made according to the “duck” scheme, containing the fuselage, the main wing of a rectangular shape in plan, vertical tail with rudder, engine with propeller, front horizontal tail (PGO), consisting of one bearing surface, rectangular in plan. Achievement of the longitudinal stability of this ekranoplan is achieved only due to the selected in a certain way: areas, aerodynamic shoulders, elongations, installation angles PGO and aft wing. The disadvantage of the ekranoplan is that longitudinal stability is provided only at small relative distances (up to $$\overline{h}>0,\mathrm{one}$$

) and for small wave-wave perturbations. Such an ekranoplan can be called self-stabilizing (in this case, in the longitudinal plane of movement) only in a small range of operational distances. Note that self-stabilization refers to such a property of an ekranoplan, when, after exposure to an external disturbance, with a new position of the aircraft, without the intervention of control, the necessary stability margin of the aircraft is maintained to compensate for all external windwave disturbances acceptable for ekranoplanes of this seaworthiness class.

Known self-stabilizing ekranoplan [Pat. 2224671 Russian Federation, IPC ⁷ B60V 1/08. Self-stabilizing ekranoplan / Surzhik V.V., Skorokhodov P.A. etc., the applicant and patent holder Closed Joint-Stock Company “PSD Technologies” - No. 2003100793; declared 01/09/03, - publ. 02/27/04. Bull. No. 6. - 5, p: Il.1.], Made according to the “duck” scheme, containing the fuselage, in front of which is installed a rectangular shape in plan anterior horizontal plumage (PGO), and in the aft part of the fuselage - a wing of small elongation with mounted on it two-pitch vertical plumage with rudders. Engines with propulsors are located in the nose of the fuselage above the PGO with the possibility of rotation around the horizontal axis.

Achieving the stability of this ekranoplan is ensured by the ratio of the areas S ₁ , S ₂ and the shoulders L ₁ , L _{2 of the} PGO and the main wing, respectively, chosen by the authors.

; $${\overline{L}}_2=\frac{L_2}{L_1}=0,59-4,5$$

. $${\overline{S}}_2=\frac{S_2}{S_{\mathrm{one}}}=0,2-\mathrm{one},0$$

; $${\overline{L}}_2=\frac{L_2}{L_{\mathrm{one}}}=0,59-\mathrm{four},5$$

.

Also in the first part of the patent claims [2] it is stated that the longitudinal stability zone of the apparatus should be below the limits of the ratio:

. $${\overline{S}}_2={\left(0,598417+0,592371\cdot {\overline{L}}_2+0,138457{\overline{L}}_2^2\right)}^{-\mathrm{one}}$$

.

In the distinctive part of the patent claims [2], it is stated that the proposed self-stabilizing ekranoplane differs in that the relative elongation of the horizontal tail is less than the relative elongation of the wing of small elongation (that is, λ _PGO <λ _cr ).

According to the content of the above invention, the following disadvantages can be noted:

- PGO of rectangular shape in plan, of small elongation, having the usual plane-convex or symmetrical profile on the ekranoplanes of the “duck” scheme, is able to provide longitudinal stability only in the range of very small windwave disturbances and only at relative distances significantly less than 0.1. This is due to the fact that the influence of the proximity of the screen on the bearing surface of small elongation is significantly lower than on the bearing surface of large or medium elongations, and, therefore, the stabilizing moment provided by such a PGO, when the winged aircraft moves at moderate distances, will be clearly insufficient;

Known self-stabilizing ekranoplan ADP-07 [A.S. No. 1316170 USSR, IPC B60V 1/08, Ekranoplans according to the “duck” scheme / Popov KB, Gusev I.N. and others - No. 3928768 / 40-23; declared 07.17.85, - publ. 27.11.85.], Made according to the "duck" scheme, containing the fuselage, main wing, vertical tail with rudder, engine with propulsion device, PGO, consisting of front and rear parts connected by common side washers, forming the so-called "back slit". Achieving the longitudinal stability of a given ekranoplan having a PGO “with a back slit” [Panchenkov A.N., Examination of ekranoplanes / A.N. Panchenkov, P.T. Drachev, V.I. Lyubimov / N. Novgorod. LLC Printing House Volga Region, 2006. S.600-601], is achieved due to the fact that the installation angles and the position along the height of the front part relative to the rear part of the VGE provide, with an increase in the pitch angle of the ekranoplan, an increase in the intensity of vortex bundles coming off the front parts of such a PGO. These harnesses, falling under the lower surface of the back of the PGO, reduce the total pressure drop on the PGO. This leads to the fact that in a certain range of increment of pitch angles and distances, there is a more gentle dependence of the PGO lifting force on the angle of attack or even a drop in the PGO lifting force as a whole in a certain range of pitch angles and distances. As a result, when using such a PGO, when exposed to oncoming and counter-lateral wind gusts, the longitudinal stability of the ekranoplan in a certain range of pitch angles improves.

However, when using the common side washers to connect the front and rear parts of the PGO, the intensity of the vortex bundles coming down from the front of such a PGO is significantly weakened due to their destruction and braking from the contact of the surface of these common side washers. This leads to a significant decrease or even the disappearance of the effect of a drop in the lifting force on such a PGO with an increase in the pitch angle of the winged craft.

The disadvantage of this ekranoplan [Panchenkov A.N., Drachev P.T., Lyubimov V.I. Examination of ekranoplanes. N. Novgorod. LLC Printing House "Volga Region", 2006, S.600.] Are:

- an insufficiently wide range of pitch angles and PGO distances, at which a smaller influence of the angle of attack on the PGO lift is observed. This leads to a decrease in the margin of longitudinal stability required to compensate for the influence of external wind-wave disturbances;

- the use of a non-arrow-shaped supporting surface as a front part of the PGO, on the one hand, reduces the intensity of the vortex bundles creating the effect described above, on the other hand, it increases the lifting force on the front of the PGO. All this reduces the effect described above and as a whole reduces the margin of longitudinal static stability.

The considered last self-stabilizing ekranoplan is the closest analogue in terms of the set of essential features to the claimed one and is taken as a prototype.

The task to which changes in the design of the self-stabilizing ekranoplan are directed is to improve the characteristics of the longitudinal stability of the ekranoplan under the action of windwave disturbances.

The specified technical result is that:

- as a result of external wind wave disturbances and deviations from a given position in the longitudinal plane in a certain range of pitch angles, a more pronounced return moment provided by aerodynamic forces will be observed;

- under the action of oncoming wind gusts, leading to an increase in the pitch angle of the ekranoplane in the working range of angles of attack, there is no sharp increase in the lift force of the PGO, and in some cases there is a decrease in it, leading to the exclusion of the moment of cabling, which can lead to the overturning of the ekranoplan. Together with the compensating moment of the wing arising with a time delay, this leads to the fact that the ekranoplane behaves stably under the action of large wind disturbances, which ensures a greater operational range for the use of the ekranoplan in terms of distance and pitch angle. Quantitatively beneficial effect is also expressed:

- to increase the stock of longitudinal static stability of the ekranoplan;

- improving the dynamic properties of the ekranoplan, in particular reducing the amplitude and time of the transition process.

The specified technical result is ensured by the fact that in a self-stabilizing ekranoplane made according to the "duck" scheme containing the fuselage, the front horizontal tail (PGO), the main aft wing, the vertical tail with a rudder, the main engine with a propeller, according to the invention, the PGO is made in the form of a front (PNP) and rear (ZNP) bearing surfaces connected to each other by a central pylon, while the PNP is made in the form of a wing with a sweep of 30 ... 75 ° along the front edge and zero along the trailing edge, and the ZNP is made and a wing zero sweep of the leading edge and curved trailing edge of the negative sweep angle at zero pitch having the same equidistance from the horizontal plane along its entire length, the parameters ANP and RFP are selected from ratios: Elongation PNP λ _EOR elongation RFP λ _ZNP lies in the range of 0.7 ... 1.3; the ratio of the area of PNP S _PNP to the area of ZNP S _ZNP is in the range of 0.15 ... 0.6; the ratio of the angle of attack of the PNP α _PNP to the angle of attack of the PNP α _ZNP lies within 1.2 ... 1.5, in position the rear edge of the PNP in the longitudinal direction is ahead of the front edge of the PNP at a distance r, determined from the ratio r / b _PNP = 0 ... 0.5, where b _PNP is the average aerodynamic chord of the PNP, and in height the rear edge of the PNP is lower than the front edge of the PNP by the value h selected from the ratio h / (h _PK -h _ЗК ) = 0.3 ÷ 1.0, where h _PC -h _ZK - excess of the front edge of the RFP over its trailing edge.

The essence of the design changes of the self-stabilizing ekranoplan is that the relative position and the selected parameters of the EOR and EOR ESP under the action of oncoming wind gusts make it possible to enhance the self-stabilization properties inherent in ekranoplanes of this class.

So, the choice of the geometry of the PNP is defined in the form of a wing with a sweep of 30 ... 75 ° along the leading edge and zero along the trailing edge, which in flight above the supporting surface with a positive angle of attack as a result of the descent of the air flow from the swept edges of the PNP contributes to the formation of vortices behind this bearing surface . In this case, the ZNP is made in the form of a wing with zero sweep along the leading edge and an arched trailing edge of negative sweep at a zero pitch angle having the same distance from the horizontal plane along its entire length.

The action of the oncoming wind gust on the PGO leads to an increase in the angle of attack of its bearing surfaces, to the appearance of a disturbing moment from the additional increment of the lifting force on the PGO, resulting in an initial increase in the pitch angle. In this regard, the angle of attack and the pressure drop on the lower and upper sides of the PNP increase and, consequently, the side vortices that fall under the PNP become more intense.

A further increase in the angle of attack of the VGE leads to a further increase in the power of the vortices coming from the lateral edges of the PNP and an approximation in height of the axis of the vortices to the level of the leading edge of the ZNP;

In this case, the position of the ZNP relative to the PNP for removal in the longitudinal direction is selected from the condition that the trailing edge of the ZNP in the longitudinal direction is ahead of the front edge of the ZNP at a distance g, determined from the relation

r / b _PNP = 0 ... 0.5,

where b _PNP is the average aerodynamic chord of the PNP, and in height the trailing edge of the PNP is lower than the front edge of the PNP by the value of h selected from the relation

h / (h _PC -h _ЗК ) = 0.3 ÷ 1.0,

where h _PC -h _ЗК - excess of the front edge of the RFP over its trailing edge. Such a mutual arrangement of the PNP to the PNP leads to the fact that during the stabilization of the ekranoplan the axes of the formed vortices from the PNP do not exceed the level of the leading edge of the PNP, i.e. the bulk of the airflow swirling by the PNP falls under the ZNP.

The effect of a decrease in the increase in the lifting force on the VGE with an increase in the angle of attack, and in some cases even its decrease, is provided by an increase in the velocity of airflow around the airflow due to the vector addition of the velocities of the air particles from the pressure head in the longitudinal direction and from the circulation in the transverse vortex. An increase in the air flow rate near the ZNP from the lower side according to Bernoulli's law will be accompanied by a decrease in pressure on the ZNP.

The choice of the geometry of the PNP in scope from the condition that the ratio of the elongations of the PNP and ZNP lies in the range

λ _PNP / λ _SNP = 0.7 ÷ 1.3,

areas of PNP and ZNP in the range

S _PNP / S _ZNP = 0.15 ÷ 0.6, angles of attack of PNP and ZNP

α _PNP / α _SNP = 1.2 ÷ 1.5,

defined so that the vortices converge near the lateral edges of the RFP, enhancing the described effect.

The decrease in the lifting force of the PGO is enhanced by the fact that the vortices coming from the PNP are added in the direction of rotation with the descending vortices from the lateral edges of the ZNP, thereby enhancing this effect of the flow of air flow in the region of the lateral edges from the lower side of the ZNP to the upper, thereby reducing the drop pressure from below and above, which means reducing the increase in lifting force.

The fastening of the PNP and ZNP to each other by the central pylon facilitates the free exit of the vortices from the PNP and the further development of the swirl in the direction of the ZNP, in contrast to the fastening of the PNP and ZNP with side washers, where this process is less pronounced due to the partial destruction of the vortices about them.

The effect of reducing the increase in lift on the VGE with an increase in the angle of attack in the working range of the pitch angle variation of the winged wing results in the fact that when the airflow passes through the VGO, the increment in the lifting force is significantly reduced and there is no convertible moment capable of translating the winged wing to unstable pitch oscillations. With the subsequent propagation of the perturbed air flow to the main wing, an increase in the lifting force occurs on the main wing and, as a result, the appearance of a stabilizing moment on the dive, which leads to further alignment of the ekranoplan in the air flow over the supporting surface.

Expanding the range of working angles of attack of the described effect of reducing the increase in lift on PGO with an increase in the angle of attack leads to the expansion of the range of operation by distance.

This effect will be observed when flying off-screen. When flying near the screen, it can manifest itself more vividly, and the dependence of the PGO lifting force on the angle of attack (in a certain range of angle of attack) will be not only more gentle, but even somewhat negative.

Using this effect on the WIG of an ekranoplan in a certain range of pitch angles will increase the margin of longitudinal static stability, improve the dynamic properties of an ekranoplan, in particular, reducing the amplitude and time of the transition process.

The scope of the claimed self-stabilizing ekranoplan - year-round operation over water, snow, ice, steppe, desert and other types of relatively flat underlying surfaces.

The figure 1 shows a self-stabilizing ekranoplan, made according to the scheme "Duck". The winged wing contains a main wing 1, a back-slit PGO 2, a vertical tail 3 with a rudder, a fuselage 4, mid-flight engines with propulsion 5 in the aft of the aircraft and starting engines with propulsion 6 - in the bow, landing gear 7. Moreover, the PGO is made in the form of the front (PNP ) and back (ZNP) bearing surfaces interconnected by a central pylon. In this case, the PNP is made in the form of a wing with a sweep of 30 ... 75 ° along the leading edge and zero at the trailing edge, and the PNP is made in the form of a wing with zero sweep along the leading edge and an arched trailing edge of negative sweep at a zero pitch angle that has the same distance from the horizontal plane along its entire length. The parameters of the PNP and ZNP are selected from the relations: the elongation of the PNP λ _PNP to the extension of the ZNP λ _ZNP is in the range of 0.7 ... 1.3; the ratio of the area of PNP S _PNP to the area of ZNP S _ZNP is in the range of 0.15 ... 0.6; the ratio of the angle of attack of the PNP α _PNP to the angle of attack of the SNP α _ZNP is in the range of 1.2 ... 1.5. In position, the rear edge of the PNP in the longitudinal direction is in front of the front edge of the ZNP at a distance r, determined from the ratio r / b _PNP = 0 ... 0.5, where b _PNP is the average aerodynamic chord of the PNP. In height, the rear edge of the PNP is set below the front edge of the RFP by the value of h selected from the ratio h / (h _PK -h _ZK ) = 0.3 ÷ 1.0, where h _PC -h _ZK is the excess of the front edge of the RFP over its trailing edge .

The figure 2 shows the design of the proposed PGO, which consists of two bearing surfaces: the front (PNP) in the form of a wing with a sweep of 30-75 ° along the leading edge and zero on the trailing edge and the rear bearing surface (ZNP) with zero sweep on the leading edge and trailing edge with one level in scope (its projection on the frontal plane represents a horizontal line), interconnected by a central pylon. The parameters of the PNP and ZNP are chosen so that the ratio of the elongations of which is equal to λ _PNP / λ _ZNP = 0.7 ÷ 1.3, the ratio of the areas S _PNP / S _ZNP = 0.15 ÷ 0.6, the ratio of the angles of attack α _PNP / α _ZNP = 1.2 ÷ 1.5, while the position of the trailing edge of the PNP in the longitudinal direction is ahead of the front edge of the ZNP at a distance r in relation to the average aerodynamic chord b of the _{ANP of the} front bearing surface r / b of the _PNP = 0 ÷ 0.5, and by height, the rear edge of the PNP is lower than the front edge of the RFP by the value of h selected from the ratio of 0.3 ... 1.0 excess h _PC -h _{ZK of the} front edge of the RFP over its trailing edge h / ( h _PC -h _ЗК ) = 0.3 ÷ 1.0.

The operation of this device is as follows. Under the action of a headwind gust, the ekranoplane deviates for cabling in the longitudinal plane from its initial position. However, due to the beneficial effects that occur during the interaction of its PGO with a disturbed air flow with an increase in the angle of attack in the working range of the angles of attack of the winged aircraft, this leads to the fact that when the air stream passes the PGO, the increment of the lifting force on it is reduced and there is no convertible moment capable of transfer the ekranoplan to its capsizing. Further propagation of the disturbance to the main wing of the ekranoplan leads to an increase in the lifting force on the main wing and, as a result, to the emergence of a stabilizing moment for diving, which leads to further alignment of the ekranoplan in the air flow above the supporting surface. The action of the forces and moments of the ekranoplan with a counter wind gust in flight in the absence of the influence of the screen effect is similar.

Claims (1)

Self-stabilizing ekranoplane made according to the "Duck" aerodynamic scheme, containing the fuselage, front horizontal tail (PF), main aft wing, vertical tail with rudder, engine with propulsion, characterized in that the PF is made in the form of front (PNP) and rear ( ZNP) of bearing surfaces interconnected by a central pylon, while the PNP is made in the form of a wing with a sweep of 30 ... 75 ° along the leading edge and zero sweep on the trailing edge, and the ZNP is made in the form of a wing with a zero sweep along the leading edge and the arched trailing edge of the negative sweep at a zero pitch angle that has the same distance from the horizontal plane along its entire length, while the parameters of the PNP and ZNP are selected from the relations: the ratio of the elongation of the PNP λ _PNP to the extension of the ZNP λ _ZNP is in the range 0 , 7 ... 1.3; the ratio of the area of PNP S _PNP to the area of ZNP S _ZNP is in the range of 0.15 ... 0.6; the ratio of the angle of attack of the PNP α _PNP to the angle of attack of the PNP α _ZNP lies within 1.2 ... 1.5, while the position of the rear edge of the PNP in the longitudinal direction is set in front of the front edge of the ZNP at a distance r, determined from the ratio r / b of the _PNP = 0 ... 0.5, where b _PNP is the average aerodynamic chord of the PNP, and the height of the rear edge of the PNP is lower than the front edge of the ZNP by the value h selected from the ratio h / (h _PK -h _ЗК ) = 0.3 ÷ 1.0, where h _PC -h _ЗК - excess of the front edge of the RFP over its trailing edge.

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