RU2711633C2 - Short take-off and landing aircraft with gas-dynamic control - Google Patents

Abstract

FIELD: aviation.SUBSTANCE: invention relates to aircraft engineering, particularly, to short take-off and landing aircraft structures. Aircraft comprises airfoil section with top bulged surface. Propulsion units are arranged in channels connecting air intakes of constant area and slotted nozzles arranged on upper surface of wing between inlet device and rear edge of profile. Constant area inlet devices can be arranged in an arbitrary area of the upper convex surface of the aerofoil between the leading edge of the profile and its upper point. To create control forces and moments propulsion units are arranged in two groups located transversely to direction of flight, with uniform disposition relative to longitudinal axis of aircraft in composition of each group and possibility to independently vary thrust force.EFFECT: higher efficiency of aircraft and its reliability, efficiency of control, simplified design.4 cl, 5 dwg

Description

The invention relates to the field of aviation, namely to aircraft short take-off and landing and free flight. For vertical take-off and landing of an aircraft, a vertical thrust of 10-20% higher than the take-off mass of the aircraft is required. (Encyclopedia "Aviation", TsAGI named after prof. N.E. Zhukovsky, ed. "Big Russian Encyclopedia", Moscow, 1994, p. 501). During vertical take-off, the aircraft powerplant provides vertical thrust and, only after gaining the necessary height, provides the horizontal thrust component.

To increase the target load and fuel supply, vertical takeoff and landing aircraft may have a short takeoff mode or a short takeoff along a vertically inclined path. In this case, the power plant of the aircraft creates both vertical and horizontal thrust. But even in this case, a high power ratio of the aircraft is required (Encyclopedia Aviation, TsAGI named after Prof. N.E. Zhukovsky, ed. Big Russian Encyclopedia, Moscow, 1994, p. 502).

There is a method of creating vertical thrust as well as control forces and moments, which consists in moving air volumes using external fans located in the fuselage and in the wing (EI Ruzhitsky "American vertical take-off aircraft", M., Astrel Publishing House LLC, LLC "Publishing house AST", 2000). By changing the direction of the air flow coming from the fans, it is possible to obtain the required control torque in the corresponding control channel. Known aircraft vertical takeoff and landing with a turbofan propulsion system (XV-5A). The power plant of the aircraft consists of two turbojet engines (turbojet engines) and three fans installed in the fuselage (one) and in the wings (two). In vertical flight modes, the turbojet gases drive the fans to rotate, and in horizontal modes, the gases flow out through the jet nozzles of the engines. Fans have deflectable output louvers. Transverse and directional control of the aircraft in vertical modes is carried out by differential deflection of the blinds of the wing fans. Longitudinal control is provided by a fan mounted in the fuselage. In horizontal flight modes, the aircraft is controlled by conventional steering surfaces. The fan flaps, in the open state providing air access, in horizontal flight, are closed. The disadvantage of this method and device that implements it is the large length of gas pipelines connecting the turbojet engine with turbines, which rotate the fans and the complexity of the technical system for turning the blinds and fan shutters.

In addition, the use of deflectable steering surfaces increases the visibility of such aircraft.

Similar examples of solving a similar problem are known from the patent information, for example, RF patent 2531432 dated December 4, 2012, B64C 29/00.

An aircraft that implements a method of creating a system of forces for an aircraft of vertical take-off and landing (RF patent 2531432 dated December 4, 2012, B64C 29/00) contains an aerodynamic wing with an upper convex surface, in which a non-stationary supersonic ejector formed by a system of channels connecting a constant-area air intake gap, which is a marching inlet device located at the leading edge of the profile, and a constant-area air intake gap, which is a starting inlet device, Assumption at the top of the airfoil; air flows from the inlet devices are connected in the area of the fuel manifold, and the combustion products formed in the mixing chamber flow out through a slotted nozzle located on the upper surface of the wing between the starting inlet device and the trailing edge of the wing.

Partially eliminating the negative qualities of the considered analogue, such an aircraft has its drawbacks, namely:

- to maintain a self-regulating duty cycle, careful resonant tuning of the system of channels forming a non-stationary ejector is required;

- high visibility of the aircraft in the infrared and acoustic ranges, due to the expiration through the slot nozzle of an unsteady stream of combustion products;

- at the take-off and landing stage, and when performing a horizontal flight, it is possible to control only along the pitch channel.

More successfully, the problem of creating control forces and moments for vertically taking off aircraft is solved in various multicopter.

Closest to the proposed invention relates to a multicopter with a linear arrangement of propeller groups (RF patent No. 2577822 from 03/20/2016, B64C 27/08), selected as a prototype.

Such a multicopter with a linear arrangement of propeller groups arranged by lines elongated along the flight direction, contains a propeller group of longitudinal power beams - spars located along the flight, to which transverse power beams are attached, at the ends of which electric motors with rotor propellers are installed, one at a time on the ends of each transverse beam, from the bottom to the platform of the propeller groups, a cargo-passenger cabin with battery packs is attached, with propeller installations must provide load multicopter in air robot embodiments, air motorcycle microcar, gruzotaksi, bus, infantry fighting vehicles, etc., but not less than 9 pairs (18 propeller groups) for the reliability of an emergency landing in case of failure to 4 motors simultaneously.

Flight control basically happens the same way as with the radial arrangement of the propeller groups (VMG). With an increase in the speed of the rear VMGs and a decrease in the front, the multicopter moves forward. When manipulating the left and right groups, the multicopter will move to the right or left. Special software control of the screws allows you to deploy the aircraft, change course, change speed and altitude. The on-board navigation and flight complex allows this aircraft to fly according to the program, as well as manually control the autopilot both from the ground and from the side of this aircraft.

Partially eliminating the negative qualities of the considered analogues, such an aircraft has its drawbacks, namely:

- in comparison with a winged aircraft at the same speed and flight weight, the engine power should be twice as large;

- emergency landing in autorotation mode, unlike a helicopter, is impossible;

- a large number of VMG reduces the reliability of the aircraft.

The objective of the invention is to remedy these disadvantages and create an aircraft short take-off and landing with gas-dynamic control, which has high efficiency and reliability.

This goal is achieved due to the fact that in an aircraft of short take-off and landing, with propulsion systems located inside the wing of an aerodynamic section with an upper convex surface in the channels connecting the air intakes of a constant area, which are inlet devices, and slotted nozzles located on the upper surface of the wing between inlet devices and the trailing edge of the profile; moreover, the inlet devices of constant area can be located in an arbitrary region of the upper convex surface of the aerodynamic profile between the front edge of the profile and its upper point, to create control forces and moments of the propulsion system, are placed in two groups located transverse to the flight direction, with a uniform disposition relative to the longitudinal axis aircraft in each group and the ability to independently vary the thrust. The distance of the propulsion systems from the longitudinal axis of the aircraft is different in different groups. As propulsion systems can be used turbojet engines, impellers with high-speed electric motors or impellers driven by a piston engine. The thickness of the wing in its scope can be variable.

The combination of the mentioned features solves the problem of short take-off and landing, allows us to simplify the design of the aircraft, increase its efficiency and reliability, and increase the efficiency of control of the aircraft.

The invention is illustrated by drawings (Fig. 1), which shows a longitudinal section of the aircraft along the channels of propulsion systems (DU) (III-III) and (Fig. 2), which shows a top view of the aircraft, as well as the formation of control forces and moments (FIGS. 3, 4, and 5). The drawings show a variant with four propulsion systems in the form of impellers with high-speed electric motors installed in two groups.

The aircraft according to claim 1, comprises a wing of aerodynamic section 1 with an upper convex surface 2, inside of which there are channels 3, connecting inlet devices of constant area 4, located on the upper surface of the aerodynamic profile, with slotted nozzles 5, and an impeller is placed inside each channel 3 propulsion system with a high-speed electric motor 6. Propulsion systems are placed in two groups (II and II-II) located transversely to the flight direction of the aircraft.

The aircraft operates as follows. Air from the environment enters, due to forced convection, through inlet devices 4 through channels 3 to impeller propulsion systems with high-speed electric motors 6, it is accelerated by impellers to a speed of 60-80 m / s and expires through slotted nozzles 5 to the upper convex surface 2 of wing 1, adhering to it under the influence of the Coanda effect. The jet flowing from the wing creates the effect of increasing circulation around the profile due to the involvement of the surrounding air in the movement. The vertical component of the traction force Y exceeds the horizontal component P. The simultaneous action of the vertical and horizontal components of the traction force leads to a short take-off of the vehicle. After the aircraft reaches the required height, the impeller speed decreases synchronously until the lift and the weight of the aircraft are balanced, after which it moves from the take-off stage to the horizontal flight stage.

If the revolutions of the impellers of the front group (II) exceed the revolutions of the impellers of the rear group (II-II), and, accordingly, with a larger value of the velocity of air flow through the slotted nozzles, the pressure on the upper surface of the wing drops, and the lifting force of the wing in the region where the impellers of the front group increases (“Aerodynamics and flight dynamics of maneuverable aircraft”, under the editorship of Prof. N.M. Lysenko, Moscow, Military Publishing House, 1984, p. 50).

The longitudinal and transverse distribution of these pressure regions relative to the center of mass thus determine the possibility of direct control of the lifting force, as well as the moments of yaw and roll. Depending on the aerodynamic characteristics of the wing, the configuration of the aircraft and the kinematic characteristics of its movement, which are determined during the design of a specific aircraft, it is possible to provide a control moment along the pitch channel.

Control moments along the roll and yaw channels are created simultaneously by changing the speed of the impellers, independently of each other. This makes it possible to obtain a horizontal component of the thrust force of varying magnitude along the wing span, which simultaneously leads to the appearance of a control moment along the yaw channel, and a different magnitude of lifting force along the wing span, which provides control moment along the roll channel.

The diagrams (Figs. 3, 4, and 5) show changes in the control forces and moments for an aircraft with a variable thickness over a wing span. Impellers of the front group are located at a greater distance from the longitudinal axis of the aircraft than impellers of the rear group. The variable thickness of the wing in its span makes it more convenient to place propulsion systems in the wing.

превышает подъемную силу крыла в области размещения задней группы импеллеров Y_з. На схеме (фиг. 4) показано пропорциональное изменение оборотов импеллеров передней и задней групп, приводящее к уменьшению подъемной силы крыла

и увеличению подъемной силы Y_з. Точка приложения подъемной силы Y и величина соответствующего момента зависит, прежде всего, от формы аэродинамического профиля крыла и скорости истечения через щелевые сопла. При увеличении скорости истечения точка приложения Y перемещается ближе к срезу щелевого сопла (Г.М. Цейтлин, М.И. Сольц, Е.В. Гладких «Аэродинамика и динамика полета реактивного самолета», Москва, Военное издательство МО СССР, 1964, с. 117).In the diagram (Fig. 3), in the case of an increase in the speed of the front group of impellers, and, consequently, a decrease in pressure on the upper surface of the wing, the lifting force in this zone of the wing

exceeds the wing lift in the area of the rear group of impellers Y _s . The diagram (Fig. 4) shows a proportional change in the revolutions of the impellers of the front and rear groups, leading to a decrease in the lifting force of the wing

and increase the lifting force Y _s . The point of application of the lifting force Y and the magnitude of the corresponding moment depends, first of all, on the shape of the aerodynamic profile of the wing and the velocity of outflow through slotted nozzles. With an increase in the outflow velocity, the application point Y moves closer to the slit nozzle exit (G.M. Zeitlin, M.I. Solts, E.V. Gladkikh, “Aerodynamics and dynamics of a jet airplane flight,” Moscow, Military Publishing House of the USSR Ministry of Defense, 1964, p. . 117).

и уменьшению подъемной силы

на левой плоскости, что изменяет продольные составляющие сил

(справа) и

(слева) и, аналогично тому, как это происходит на летательных аппаратах, имеющих совмещенные рули направления и высоты в составе V-образного оперения (самолеты Beechcraft Bonanza, Fouga СМ. 170 Magister, Lockheed F-117 Nighthawk), одновременно образует управляющие моменты по каналу рыскания - М_z и каналу крена М_х. в результате летательный аппарат совершает левый вираж. При выравнивании оборотов левого и правого импеллеров величина подъемной силы крыла на правой

и левой

плоскостях будут одинаковыми, продольные составляющие сил

и

также становятся одинаковыми и летательный аппарат будет совершать прямолинейный полет.The diagram (Fig. 5) shows an increase in the speed of the right (in the direction of flight) impeller of the front row and a decrease in the speed of the left impeller of the same row. This leads to an increase in the lift of the wing on the right plane.

and reduced lift

on the left plane, which changes the longitudinal components of the forces

(right) and

(left) and, similarly to how this happens on aircraft with combined rudders and altitude as part of the V-tail (Beechcraft Bonanza, Fouga CM. 170 Magister, Lockheed F-117 Nighthawk aircraft), simultaneously generates control moments for yaw channel - M _z and roll channel M _x . as a result, the aircraft makes a left turn. When aligning the revolutions of the left and right impellers, the value of the wing lift on the right

and left

planes will be the same, the longitudinal components of the forces

and

also become the same and the aircraft will perform a straight flight.

A uniform decrease in the speed of all impellers with a decrease in the lift of the apparatus less than the weight of the aircraft translates it into an inclined path of decline.

An aircraft made according to an airplane scheme without rotors has a lower power of the propulsion system at the same take-off mass and flight speed, or a higher flight speed. The absence of steering surfaces and rotary VMG simplifies the design of the aircraft and its reliability. When engine systems fail, the aircraft can plan and land. The interaction of the upper convex surface of the wing with cold jets of air flowing out through slotted nozzles (if impellers are used as propulsion systems) allows them to be made of light materials, which will favorably affect the economy of the aircraft.

Claims (4)

1. Aircraft with a short take-off and landing with gas-dynamic control with a longitudinal arrangement of propulsion systems located inside the wing of the aerodynamic section with an upper convex surface in the channels connecting the air intakes of a constant area, which are inlet devices, and slotted nozzles placed on the upper surface of the wing between the inlet devices and trailing edge of the profile; moreover, the constant-area inlet devices can be placed in an arbitrary region of the upper convex surface of the aerodynamic profile between the front edge of the profile and its upper point, characterized in that the propulsion systems are placed in two groups located transverse to the flight direction, with a uniform disposition relative to the longitudinal axis of the aircraft in the composition of each group and the ability to independently change the traction force. 2. Aircraft of short take-off and landing with gas-dynamic control according to claim 1, characterized in that the distance of the propulsion systems from the longitudinal axis of the aircraft is different in different groups. 3. Aircraft short take-off and landing with gas-dynamic control according to paragraphs. 1, 2, characterized in that as propulsion systems can be used turbojet engines, impellers with high-speed electric motors or impellers driven by a piston engine. 4. Aircraft short take-off and landing with gas-dynamic control according to paragraphs. 1, 2, 3, characterized in that the thickness of the wing in its span can be variable.

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