RU2491206C2 - Method and device for lift generation for vtol aircraft - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to rotorcraft, namely, to VTOL aircraft. Proposed method consists in feeding gas-air mix from the source to preset parameters: rate, pressure, density and temperature, to airfoil end wing. Note here that wing tip is directed inward the ring, to geometrical center. Aforesaid source and controlled nozzle are used to vary said parameters for control over aircraft lift. Proposed device consists of circular wing with tip directed inward, air jet engine, annular channel, circular nozzle and central body. Circular wing, central body and outer tubular case are interconnected by radial vertical struts.

EFFECT: increased lift, decreased power consumption.

2 cl, 5 dwg

Description

The invention relates to transport engineering, in particular to aerospace engineering and can be used to move people and goods in the atmosphere of the planets, perform transport and technological operations with significant mass and dimensions of cargo, for mounting and / or dismantling structures, or for example, for extinguishing fires from the air, etc.

A known method of creating a lifting force for an aircraft (LA) with vertical take-off and landing, implemented in an LA-helicopter [1], which consists in the fact that the necessary lifting force for its take-off, flight and landing is created by the rotor (rotor), and not a wing. To create lift, the helicopter does not need translational movement.

The disadvantages of this method and device for its implementation include the following [1]:

the need to balance the reactive moment;

significant, up to 10% power loss in the transmission when transmitting torque from the engine to the main and tail rotors, and the design uses long shafts, which leads to undesirable vibrations in this aircraft;

the difficulty of controlling the helicopter due to the requirement of strict correspondence between the pitch of the tail rotor, the pitch of the rotor and engine power.

There is also known a method of learning the lifting force for an aircraft with vertical take-off, which consists in blowing a gas-air stream at the desired angle of attack, aerodynamically profiled planes of large elongation and implemented in a device [2], which contains: a fuselage, wings mounted on both sides of the fuselage , power plants (SU) and propulsors, wings with their long sides are parallel to the longitudinal axis of the fuselage, and the wings are made in versions of a monoplane or n-plan and are equipped with ailerons, the SU is made in the form of t of jet engines (turbojet engines) mounted vertically in a row along the longitudinal axis of the fuselage and equipped with nozzles directing gas flows to the sides of the wings, screens are installed on the fuselage forming ejectors with nozzles for mixing gas flows with air and propulsors made in the form of sets of shields installed vertically rotatable and located on the path of gas-air flows.

When the gas turbine engine is turned on, the gases flowing out of them mix with the air, form gas-air flows that flow around the wings at high speed, creating lift on them. Gas flows moving above the upper surface of the fuselage create additional lifting force. The aircraft receives a vertical upward movement. To report the aircraft additional movement "forward", the flaps are deployed in a certain position. Gas-air flows, having worked on the wings and having a reserve of speed, act on the flaps, creating a horizontal traction force on them, which moves the aircraft in the horizontal direction.

The disadvantages of this method include the fact that since the creation of the lifting force on the fuselage and on the wings, as well as the traction force are created by the same gas turbine engines, the control of the aircraft along the “up-down” and “forward-backward” channels is not always will be separate, which can impede the movement of the aircraft along a given level echelon with a given course, for example, in strong winds.

There is also a method of creating a lifting or driving force for an aircraft of vertical take-off [3], taken as a prototype in which the wing is hollow in the form of a ring, in the central part of which an air flow is created through a radial slot nozzle, which is pumped so that it provides the formation of two zones of reduced pressure at the upper and lower plane of the wing with the possibility of regulating the vacuum by valves. Air is pumped into the central cavity of the wing, which is separated by winglets on both walls, with the formation of equal segments. Air is pumped through a radial slot nozzle having a sectional shape of a cone or Laval nozzle. In each segment, slots are provided at the top and / or bottom of the wing leading to the segments with the possibility of overlapping by opening / closing the valves and controlling the flow rate through the radial slot nozzle. The invention is aimed at enhancing the lifting force and sharpness of the course change.

The disadvantage of the proposed method of creating a lifting force should include the following: since, areas of reduced pressure are created in a single closed loop of the hollow wing on the inner upper and lower walls, and the pressure on the corresponding surface is controlled, in particular, by opening the valve, mixing will occur to the air stream with a large rarefaction of the air stream with a lower vacuum entering through the valve from the control zone, and this will lead to unconditional energy losses when building lift.

It is also known a device [4] for generating wing lift, comprising a wing installed at a certain angle of attack to the direction of a subsonic swirling incoming or injected fluid or gas flow at the device inlet, characterized in that the wing with a profile optimized for a given speed range is placed between a profiled deflecting surface by a deflector on the upper convex side of the wing profile and an inclined or curved plate on the opposite side of the wing profile located on certain distances from the profile, as well as two longitudinal vertically symmetric side walls, flat or multifaceted, or curved, at the ends of the wing, deflector and plate, into which they abut at their ends, forming a through symmetrical shaped flow channel corresponding to a square, rectangular, triangular , polygonal, round, oval or other vertically symmetrical cross-sectional shape of the channel into which the wing device is embedded.

The disadvantage of the proposed device can be attributed to its overload associated with the wing device elements - deflector, plate and side walls and, accordingly, the impossibility of obtaining large values of lift due to the fact that the wing device is built into a closed loop formed by these elements and the pressure difference (vacuum) on the wing device will be act additionally on these elements, and not just on the wing.

The technical result of the invention is to expand the scope of the method of obtaining lift, increase this force and / or reduce energy consumption for its application by rational distribution of energy of the gas-air stream by regulating, on the one hand, the parameters of the stream itself and, on the other, the flow conditions around this stream aerodynamically shaped wing, made in the form of a ring, with the toe inward.

To achieve this result, a method for creating lift is proposed, which consists in blowing with a controlled flow of a gas-air mixture (DHW) with controlled parameters of the last, annular wing (CC). The annular wing is performed aerodynamically profiled from the outside, spar or monoblock and sealed, while the toe of the annular wing is directed, inside the ring, to the geometric center of the latter. To obtain the lifting force, the DHW flow is taken from the source, equalized with the given parameters: temperature, density, pressure and speed (flow rate), fed through the annular channel in cross section, then through the annular adjustable nozzle, the DHW is sent to the tip of the ring wing. By acting on the above-mentioned DHW parameters through the source, the dynamics of the flow around the spacecraft profile is changed, and by means of an adjustable nozzle or part of it, the nature of the flow around the gas-air mixture of the spacecraft is changed or the direction of the flow relative to the toe of the spacecraft or its part is changed, which ensures optimal control of the lifting force, arising on the spacecraft during its flow around the hot water supply.

It is known [5] that in aerodynamics the “principle of motion reversal” is widely used, which consists in the fact that the forces acting on the aircraft do not depend on whether the body’s movement in the air is considered or, on the contrary, the air flow runs with the same speed to the body.

It is also known [5] that the aerodynamic forces acting on a body placed in an air stream are determined by the forces of friction and pressure.

Consider the latter. So, the pressure forces depend on the shape of the body, its orientation relative to the flow and the parameters of the flow itself - temperature, density, pressure and speed (flow rate). A body placed in a stream deforms it. Figure 1 shows a picture of the flow around a wing profile at a subsonic flow rate [5]. Near the leading edge, the flow is divided into two, and the critical point K is the boundary. Each of the flows can be represented as a trickle of air, which, deforming around the profile, is deformed, however, the same mass of air passes through each trickle section at the same time, which leads to according to the equation of constant flow

$$\rho fV={\rho }_{\mathrm{one}}{f}_{\mathrm{one}}{V}_{\mathrm{one}}+{\rho }_2{f}_2{V}_2=const,\left(\mathrm{one}\right)$$

where ρ is the density;

f is the cross sectional area of the trickle;

V is the air velocity;

to a change in speed and density, and hence to a change in pressure on the streamlined surface, which follows from the Bernoulli energy equation, for the case when the compressibility of air can be neglected,

$$\frac{\rho V^2}{2}+P=\frac{{\rho }_{\mathrm{one}}{V}_{\mathrm{one}}^2}{2}+P_{\mathrm{one}}=\frac{{\rho }_2{V}_2^2}{2}+P_2=const,\left(2\right)$$

- скоростной напор, в единицах давления (который иногда обозначают буквой - q):Where $$\frac{\rho V^2}{2}$$

- velocity head, in pressure units (which is sometimes denoted by the letter - q):

P is the static pressure.

In other words, the sum of the pressure head and the static pressure in the stream is a constant value. So, for example, with an increase in the cross-sectional area of the trickle, the flow velocity decreases in it, and hence the velocity head q - the dynamic component of the flow energy also decreases, but in this case its static component - P increases, and vice versa, if the cross-sectional area of the trickle decreases, then the velocity flow in it, and hence the pressure head q increases, but then the static pressure P.

So, figure 2 shows a vector diagram of the pressure distribution along the profile of the wing during its flow [6]. The arrows indicate the difference between local and atmospheric pressures at each point in the profile. Positive overpressure (atmospheric pressure less than local) is indicated by an arrow directed to the circuit, and negative or negative pressure (atmospheric pressure is greater than local) is marked by an arrow directed from the circuit.

From the diagram in figure 2, it can be seen that when the subsonic stream flows around the profile, the rarefaction on the upper surface is higher than on the lower one, as a result of which a lifting force arises on the profile directed towards a larger rarefaction, i.e. up.

In contrast to the usual flow around a wing of an airplane or a rotor blade of a helicopter, where the incoming flow, having a certain supply of energy, is divided into two flows at a critical point and then the difference in their energies is spent on creating a lifting force, in the proposed device that implements the proposed method, there is a possibility by controlled nozzle, blow with the flow of hot water mainly the upper surface of the profile. In this case, the creation of the lifting force will be spent mainly all the energy of the flow. The vector diagram of figure 2 of the pressure distribution over the wing profile will take the form - figure 3. Therefore, the power of the DHW flow source can be significantly lower.

At the same time, the fact that after the flow decelerates at the critical point K on the KK nose is also important, the subsequent decrease in speed due to the expansion of the cross section and, as a consequence, the pressure increase in the stream on the KK surface is carried out not only due to the curvature of the profile, but also due to the actual ring shape.

Consider the spacecraft in plan, Fig. 4 and select on its toe two points A and B, at a certain distance from each other, conditionally commensurate with the diameter of the cross section of the stream of flow, as in Fig. 1. If we draw through these points from the geometric center O of the annular wing, before intersecting with the trailing edge of the latter, at points C and D, two rays Oi and Oj, it turns out that the distance CD will be greater than AB.

Obviously, the shape of the spacecraft in itself creates the possibility of increasing the cross section of the trickle of the stream, (f _{2 is} greater than f ₁ ) when it moves along the radius from the nose to the periphery along the surface of the spacecraft. Therefore, it is indisputable that the above character of the flow around the spacecraft allows us to draw an analogy with the flow around a swept wing, which has several advantages over direct [5]:

more critical number M;

a smoother change in the coefficients of the lifting force Su and the frontal resistance Cx in terms of the number M at a constant angle of attack α = const;

moment characteristics change more smoothly.

At the same time, the spacecraft is also devoid of a significant drawback inherent to the swept wing - the tendency to end stall of the flow, since the annular wing has no ends.

In a supersonic flow around when the flow velocity is greater than the speed of sound, the development of supersonic zones and shock waves develops on the profile, pressure redistributes along the profile and the rarefaction zone moves to its trailing edge, which affects the aerodynamic forces acting on the aircraft [5]. This phenomenon will also be observed in the annular wing, but it will not have an effect on the spacecraft, because with uniform flow around the spacecraft nose the resultant aerodynamic forces will be applied to a certain circle on the spacecraft, whose center coincides with the center of the spacecraft, while in a supersonic flow, only the radius of this circle will increase .

All of the above allows us to conclude that the task of obtaining lift on the aerodynamic profile of spacecraft can be solved in the following ways:

redistribution of the energy of the DHW flow between the upper and lower surfaces of the spacecraft by changing the position of the critical point K on the spacecraft toe, i.e. a change in the angle of attack, in relation to the entire QC toe, uniformly;

redistribution of the energy of the domestic hot water flow over the QC sectors, also by changing the position of the critical point K by changing the angle of attack not evenly, but across the QC sectors to ensure the aircraft control process in roll and pitch, where this method can be implemented;

controlling the parameters of the DHW flow itself - temperature, pressure, speed (flow), by acting on the flow source to control the dynamics of vertical movement;

the direction of the DHW flow along the radius of the spacecraft from the nose to the periphery, and, accordingly, the redistribution of the energy of the flow when it moves along the surface of the annular wing and, as a result, the expansion of the range of operating speeds of the DHW.

The obvious advantage of the spacecraft in comparison with the traditional one, the wing of an airplane or the rotor blade of a helicopter, is its 3.14 (π) times smaller diameter in relation to the span. So, if you straighten the straight wing along its midline into a ring, it turns out this ratio.

It follows from this that, ceteris paribus, and, in particular, with commensurable dimensions, but taking into account the strength (construction) properties of the annular cross section, such as the moment of inertia and the moment of resistance, it is possible to construct without significantly aggravating the design of the spacecraft with significantly greater elongation, which for wings of any shape in plan [5] is determined by the expression:

$$\lambda \frac{{\ell }^2}{S},\left(3\right)$$

where ℓ - wingspan;

S - wing area.

So, if for a Boeing B-52 aircraft [8], with a wing span of 56.39 m and an area of 371.6 square meters, the λ value is 8.5, then a spacecraft with the same λ value will have a diameter of about 18 m.

Moreover, the elongation of the λ wing has a positive effect on the aerodynamic quality of the latter [7], especially with subsonic flow.

Thus, the application of the proposed method and device not only makes it possible to create lift, but also allows you to control it, and the shape of the spacecraft provides a number of advantages in terms of its impact on aerodynamic, geometric and strength (construction) characteristics.

That is, in the opinion of the authors, the technical result of the proposed technical solutions in the interests of obtaining lifting force, their significant difference from others and their advantage.

The technical device proposed for implementing the method is shown in Fig. 5 and includes an annular wing - 1, a gas-air mixture source, for example, a turbofan aircraft engine - 2, a conical tubular channel - 3, formed from an outer tubular casing - 4 and a central body - 5, ending adjustable annular nozzle - 6-6 ¹ , with actuators - 7.

The annular wing is made in the form of an aerodynamic profile - 8, and in plan, in the form of a ring with a geometric center - O, Fig.3. Moreover, the toe of the profile - 8, is directed to the center O of the ring. The central body - 5 (figure 5), the outer tubular casing - 4, with ejectors - 9 and the annular wing - 1, are interconnected streamlined and installed radially struts - 10. Racks located inside the annular channel also serve to straighten the flow after the source. Moreover, with the same racks the whole structure is attached through the wing to a horizontal platform - 11. On this platform, systems can be placed: technical, technological, life support and emergency abandonment, as well as aircraft compartments, including inhabited ones, cabins, fuel supplies, special liquids , gases, payloads, etc. - 12. The platform itself can rely on the chassis - 13. For the implementation of horizontal movement and directional control can be used autonomous marching SU - 14, with a variable traction vector. Ejectors - 9 can be used as an additional measure to reduce the temperature of the DHW flow supplied to the spacecraft. Despite the fact that during the operation of the turbojet engine 25 ... 35% of the air passing through its path is involved in combustion [5], and in the dual-circuit turbofan engine the ratio of hot and cold air i.e. the bypass ratio varies between 0.23 ... 3.5 [6], it is important to reduce the temperature of the hot water supply stream, not so much as to increase its density, but because of the need to reduce measures for temperature compensation of the spacecraft design.

It should be noted that the aircraft where this device can be used does not pretend to a high horizontal flight speed, since an increase in such speed will inevitably lead to a decrease in the lift on the part of the spacecraft that will be directed along the flight, since the flight speed will be deducted from the dhw speed supplied to the spacecraft from the dhw source. To eliminate this negative effect, aerodynamic and weight or moment, with respect to the march SU, can be applied, a compensator - 15 in the form of an annular half-wing, of the same diameter and profile, but with a toe on the flight.

An adjustable annular nozzle 6-6 ¹ can be formed, respectively, from two circuits 6 and 6 ¹ , each made of a wing-type jet nozzle of an afterburner aircraft engine, with a variable output geometry controlled [7] and each of the circuits can be driven by actuators - 7, for example, with hydraulic cylinders, both independently and jointly with another, according to a given program, providing the required parameters of the DHW flow directed to the QC profile.

Device operation

After starting, warming up with idle gas and testing the DHW source in modes, at the same time, so that the device does not take off, the DHW flow is directed to the bottom surface of the profile or by any known method, the DHW flow is bypassed bypassing the CC, then, at the low gas mode, the DHW bypass is stopped and through an adjustable nozzle - they direct it to the spacecraft at the angle of attack required for take-off and begin to increase the speed of the DHW flow source, which will entail a change in the parameters of the DHW flow and, in particular, its speed. The d.h.w.flow from a source through a tubular conical channel with predetermined parameters and guided by an adjustable nozzle flows onto the KK sock and evenly creates the lifting force required for detachment on it. For further vertical movement, either the speed of the DHW source is increased, or the angle of attack of the incoming DHW flow to the spacecraft toe. However, in order to rationally use the fuel resources and the power of the hot water supply source, in advance, based on experiments, determine the quality K for the annular wing (the ratio of the coefficient of lift to drag coefficient for various angles of attack), build a graph of this dependence, the polar on which and note these angles [5]. The peak of the curve will show the critical angle of attack α _cr , when the lift coefficient is maximum, but the profile drag coefficient is also high, and by drawing the tangent from the center of coordinates to the polar, we get the angle of attack that is most suitable for this particular profile at which the quality profile - To the maximum and further - the obtained values are correlated with the required and available modes of operation of the source of the DHW flow, of which there may be several.

The device is controlled through the roll and pitch channels by an adjustable nozzle and consists in increasing or decreasing the angle of attack of the DHW flow directed to the spacecraft profile in opposite sectors, respectively, in these spacecraft sectors aerodynamic forces will also increase or decrease, which will create uneven moments from these forces.

To perform some transport and technological operations, it may be necessary to rotate the device relative to its own axis, for which shields can be used, as in the above device [2].

The list of figures, drawings and other materials.

Figure 1 explains the equation of constancy of flow.

Figure 2 shows a vector diagram of the distribution of pressure along the profile of the wing when it flows around the flow from above and below the profile.

Figure 3 shows a vector diagram of the pressure distribution over the surfaces of the profile when it flows around mainly from above.

Figure 4 illustrates the shape of the annular wing and the possibility of increasing the cross section of the trickle on the surface of the annular wing when it flows around from the nose to the periphery by analogy with the flow around the swept wing.

Figure 5 presents an example of a device with the positions of the main elements and the connections between them, where the claimed method of obtaining lift for an aircraft with vertical take-off and landing can be implemented.

Information sources

1. V.M. Kots, D.E. Lipovsky, V.L. Velsky, I.P. Vlasov, V.N. Zaitsev, S.N. Kahn, V.P. Karozhitsky. The design of the aircraft. M .: Oborongiz, 1963, (p. 124, 131).

2. Application of the Russian Federation 94022100/11 MPK6 B64C 29/00, 06/27/1996, author V.A. Alekseev.

3. RF application 2010101391/11 IPC B64C 15/00, B64C 39/06, 12/20/2010, author Yu.P. Andreev

4. Application for invention 2005131763/11, IPC B63B 1/00 04/20/2007, author V.A. Kobelev

5. Reference aircraft technology. M .: Military Publishing House, 1964, (p. 224, 225, 232, 233, 240, 241, 354, 243, 244, 238, 239).

6. T.I. Ligum. Aerodynamics and flight dynamics of turbojet aircraft. M .: Transport, 1967, (p. 29, 69).

7. Aviation Handbook, ed. V.M. Lavsky. Military Publishing House of the Ministry of Defense of the USSR, M .: 1964, (p.40, 98, fig. 47, pos.31, 33, 34).

8. N.I. Ryabinkin Modern combat aircraft. Minsk, LLC “Elaida”, 1997, (p.209).

Claims (2)

1. A method of creating a lifting force for an aircraft with vertical take-off, in which the wing is made in the form of a ring, characterized in that the annular wing is aerodynamically profiled from the outside and sealed, while the toe of the annular wing is directed inside the ring, to the geometric center of the latter, to obtain lifting force, the air-gas mixture flow, which is taken from the source, is evened out with the given parameters: temperature, density, pressure and flow rate, along the annular channel in the section ending with with an annular adjustable nozzle, they are directed to the tip of the annular wing and then act through the source on the above parameters of the gas-air mixture and / or by means of the adjustable nozzle or its part change the dynamics of the flow around the annular wing air-gas mixture and / or the flow direction with respect to the tip of the annular wing or its parts than provide optimal lift control. 2. A device for creating a lifting force, consisting of a wing with a profile optimized for a given speed range, characterized in that the wing is sealed along the contour, has a ring shape in plan, with a toe inside the latter, an air-gas mixture is fed to the side of the toe through an adjustable annular nozzle with actuators, which ends with the annular channel formed from the outer tubular casing with ejectors and the central body of a conical shape, established by broadening to the toe of the annular wing of the coax but with the vertical axis of the annular wing passing through its geometric center, on the outer tubular casing there is a source of air-gas mixture flow, for example, a dual-circuit turbofan engine, the annular wing, the central body and the outer tubular casing are interconnected by vertical streamlined and installed radially struts, racks, installed inside the annular channel, serve simultaneously to straighten the flow of the gas-air medium flowing from its source.

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