RU180474U1 - Vertical takeoff and landing airplane - Google Patents

Abstract

The layout of a vertical take-off and landing airplane is presented, combining the advantages of a quadrocopter at the stages of vertical take-off and landing with the advantages of a normal-mode airplane in horizontal cruise flight. The basis is a high-wing aircraft with a large elongation wing, a V-tail and a propelling marching propeller. Vertical take-off and landing are provided by four hoisting electric motors with propellers located at the ends of two longitudinal beams fixed under the wing to the left and right of the plane of symmetry of the aircraft. Distinctive features of the proposed layout are straight non-sweeping trailing edges of the wing and tail, the perpendicularity of the axes of rotation of the ailerons, flaps and rudders of the longitudinal axis of the aircraft, the position of the propeller engine in the engine nacelle above the tail of the fuselage, the inverted V-tail and the four-leg wheeled chassis, easily modified ski and float options.

Description

The utility model relates to aviation, namely to vertical take-off and landing aircraft (VTOL).

The main area of application of the proposed VTOL aircraft is the organization of air traffic without reference to the existing airfield network and without the need to build new runways.

Currently, many unmanned VTOL aircraft are known, in the layout of which a normal-mode aircraft is supplemented by a multicopter support system [Eger S.M., Mishin V.F., Liseytsev N.K. et al. Aircraft Designing - M., Mechanical Engineering, 1983, 616 pp., Erokhin E., Kolomiets A. Multicopter: a new look. [Electronic resource]. URL: http://www.uav.ru/articles/multicopters.pdf (accessed July 5, 2016)], and of the whole variety of multicopter circuits, the four-screw variant is most often used, therefore called a quadrocopter.

For example, the VTOL Wingcopter with a wing of complex shape in plan and an inverted V-tail is known [[Electronic resource]. URL: http://www.wingcopter.com (accessed July 5, 2016)].

A feature of this apparatus is the installation of four propellers rotated by individual electric motors (ED) at the ends of the rotary beams mounted on the left and right wing consoles at its front and rear edges. To perform vertical take-off or landing (GDP), the beams are installed in a horizontal position, so that two screws are behind the trailing edge of the wing, and the other two screws are in front of the front. In this case, the rotation axes of all the screws become vertical, therefore the thrust P created by them is directed upward, compensates for the weight of the apparatus G, allowing it to perform vertical take-off or landing using quadrocopter technology (see Fig. 1).

To go into horizontal flight by plane, the beams of the rear screws are turned up and down using special mechanisms, and the beams of the front screws are turned up and down, occupying a vertical position, as shown in FIG. 2. In this case, the axes of all the screws rotate in the horizontal direction, so that a forward thrust R occurs during their rotation. As a result, the VTOL aircraft can perform a horizontal flight like an ordinary plane, in which four engines with propellers, overcoming the drag force X, provide translational movement, the wing creates a lifting force Y that compensates for the weight of the apparatus G, and control is carried out using aerodynamic rudders located at the trailing edges of the wing and plumage.

The use in this VTOL aircraft wing of complex shape in terms of allows for compact dimensions of the apparatus and, at the same time, solve the following problems:

- minimize energy loss for longitudinal balancing when performing vertical take-off and landing;

- to ensure a sufficient supply of longitudinal static stability in horizontal flight.

передних и задних винтов должны быть одинаковыми и такими по величине, чтобы диски винтов не перекрывали контур крыла на плановой проекции. Это необходимо для снижения потерь от обдувки крыла.Obviously, in order to solve the first problem, it is necessary to place the center of mass (CM) of the apparatus exactly in the middle between the front and rear propellers brought into position for vertical take-off and landing, as shown in FIG. 1. In other words, the longitudinal shoulders

the front and rear screws should be the same and such in size so that the screw disks do not overlap the wing contour in the plan view. This is necessary to reduce losses from blowing the wing.

The solution of the second problem requires the location of the CM in front of the aerodynamic focus of the apparatus along the angle of attack F at some distance, as shown in FIG. 2 [Kolesnikov G.A., Markov V.K., Mikhaylyuk A.A. et al. Aerodynamics of aircraft: Textbook for universities in the specialty "Aircraft manufacturing". Ed. Kolesnikova G.A. - M., Engineering, 1993, 544 p., Ill.]. It is known that the focus on the angle of attack of an isolated wing is approximately one quarter, i.e. 25% of the toe of the medium aerodynamic chord (MAR). The presence of horizontal plumage (GO) shifts the focus back in proportion to the static moment of GO, but, as a rule, no further than the middle of the MAR, i.e. no more than 50%. Accordingly, to ensure the necessary margin of longitudinal static stability, the CM should usually be located no further than 30 ... 40% of the toe of the MAR. Therefore, if, for example, a rectangular wing were used in this VTOL, then to minimize balancing losses during vertical take-off and landing, it would be necessary to lengthen the propeller beams, and to ensure stability in horizontal flight, increase the efficiency of the tail unit by increasing its shoulder and / or area, as illustrated by the sketch in FIG. 3. Here, for comparison, a part of the planned projection of the VTOL with a wing similar to the Wingcopter wing is shown to the left of the longitudinal axis, and a part of the planned projection of a hypothetical VTOL with a rectangular wing of the same area is shown on the right. As you can see, the wing with swept consoles, like the Wingcopter wing, provides a more compact layout of the device, since it allows the use of shorter beams.

The disadvantages of this VTOL can include the following layout features:

- the absence of a wheeled chassis makes it impossible to perform the usual take-off and landing on an airplane with take-off and mileage in those cases when there are all the necessary conditions for this;

- constant blowing of beams with jets from propellers reduces the efficiency of the latter, which increases energy consumption at all stages of the flight and, ultimately, affects the flight performance (LTH);

- the use of the same propellers as carriers at the stages of vertical take-off and landing, and as mid-flight in horizontal flight, makes it difficult to achieve high efficiency, which also increases energy consumption and worsens the performance characteristics;

- the presence of beam rotation mechanisms increases the weight of the VTOL aircraft, complicates the design, production technology, reduces the reliability and safety of flights;

- the complex shape of the wing in terms of swept consoles is not optimal for low subsonic flight speeds and complicates the production technology.

Quantum TRON unmanned VTOL aircraft by Quantum Systems [[Electronic resource]] is also known. URL: https.V / www.quantum-systems.com / products / quantum-tron / (accessed 05.05.2017)].

In the layout of this VTOL aircraft, a semi-elliptical wing of large elongation is used in plan with a straight trailing edge. Two longitudinal beams are installed on the wing, at the front and rear ends of which four electric motors (ED) are mounted that rotate the propellers. Using special servo drives, the EDs with screws can be rotated, so that the axis of the screws can occupy a vertical or horizontal position. With the vertical position of the propeller axes, vertical take-off and landing using quadrocopter technology is provided (see Fig. 4). Turning the axles of the front screws to the horizontal position provides traction for flying in an airplane, while the rear screws stop after turning and their blades fold, reducing drag force (see Fig. 5).

The adopted technical solutions have eliminated some of the shortcomings of the previous layout. In particular, the semi-elliptical wing shape in plan and large elongation are optimal for low subsonic speeds, since they provide high aerodynamic quality in horizontal flight. In addition, it facilitates the simultaneous fulfillment of the conditions for the optimal position of the CM for longitudinal balancing at the stages of GDP and ensuring the necessary margin of longitudinal static stability in horizontal flight. An additional advantage is the rotation of the screws compared with the rotation of the beams, since the losses from blowing in horizontal flight are much less.

The disadvantages of this VTOL can include the following layout features:

- the lack of a normal wheeled chassis makes it impossible to perform the usual take-off and landing on an airplane with take-off and mileage in cases where there are all the necessary conditions for this;

- blowing of beams by jets from propellers at the stages of vertical take-off and landing is preserved, which reduces their efficiency, increases energy consumption and worsens the performance characteristics;

- the use of the same propellers as carriers at the stages of vertical take-off and landing, and as mid-flight in horizontal flight, makes it difficult to achieve high efficiency, which also increases energy consumption and worsens the performance characteristics;

- the presence of rotation mechanisms of the screws increases the weight of the VTOL aircraft, complicates the design, worsens production and operational manufacturability, reduces the reliability and safety of flights;

- longitudinal beams protruding above the upper surface of the wing increase the loss of lift, reduce the aerodynamic quality in horizontal flight and worsen the performance characteristics;

- the semi-elliptical wing shape in terms of complicates the production technology.

Also known is the Airbus VTOL project, which eliminated some of the shortcomings of the above configurations [patent US 2016/0236774 A1, publ. 08/18/2016]. In particular, for horizontal flight in an airplane, a separate power plant with a marching propeller mounted in a nacelle mounted on a vertical tail is used. To perform vertical takeoff and landing, quadrocopter technology is used, implemented by four lifting two-bladed propellers with individual engines located in two longitudinal beams mounted on a low wing. After moving to a horizontal flight by plane, the lifting screws stop and are forcibly fixed in the “blades along the stream” position, which allows them to be isolated inside the beams from the incoming flow using special wings. The use of separate power plants for the stages of vertical take-off and landing and for horizontal flight allows to achieve high efficiency of both lifting and cruising propellers.

The location of the marching power plant in the engine nacelle outside the fuselage simplifies the cooling of the engine, increases the convenience of its maintenance and facilitates subsequent upgrades.

A feature of this VTOL project is the use of a trapezoidal wing with a straight non-arrow-shaped trailing edge, on which ailerons with a rotation axis perpendicular to the longitudinal axis of the aircraft are located. The adopted wing shape in terms of not only facilitates the simultaneous fulfillment of the conditions for optimal CM position for the stages of GDP and horizontal flight, but is also simpler and more technologically advanced in production compared to, for example, an elliptical or trapezoidal wing with an arrow-shaped trailing edge.

The presence of a wheeled chassis allows this VTOL aircraft to perform normal take-off and landing on an airplane with take-off and mileage, respectively, or shortened when there are all the necessary conditions for this. This increases the flexibility of using the VTOL aircraft, making it possible to reduce energy consumption during takeoff and landing operations, increasing the range and duration of the flight, as well as the weight of the payload.

The disadvantages of this VTOL can include the following layout features:

- high design complexity due to the presence of special devices for isolating the lifting screws from the incoming air flow in horizontal flight;

- the installation of longitudinal beams with lifting screws on the upper surface of the low wing increases the loss of lift and reduces aerodynamic quality in horizontal flight;

- the use of longitudinal beams of great length increases the area of the surface being washed and the friction resistance in horizontal flight;

- the adopted method of placing the lifting screws inside the longitudinal beams reduces the efficiency and increases the energy loss at the stages of vertical take-off and landing;

- the large weight of the vertical tail, due to the need to provide strength for the perception of loads from a highly marching propulsion system and a T-shaped horizontal tail;

- the presence of the front horizontal plumage complicates the design and increases drag in horizontal flight;

- the lack of wing mechanization increases the minimum speed of horizontal flight in an airplane, and this increases the energy consumption at the stages of acceleration in the air after vertical take-off and braking before vertical landing;

- the use of a T-shaped horizontal tail with an arrow-shaped trailing edge and rudder rotation axes that are not perpendicular to the longitudinal axis of the VTOL, reduces control efficiency, complicates the design, and degrades production and operational manufacturability.

Closest to the claimed technical solution is the unmanned VTOL AV-2 Pelican company Drone TechUAV Corporation [[Electronic resource]. URL: http://www.dronetechuav.com/ (accessed 05.05.2017)]. A feature of this VTOL adopted as a prototype is the use of two marching power plants - one located in the nose of the fuselage is equipped with a pulling propeller, and the second is in the rear of the fuselage and rotates the pushing screw. There is a four-wheeled chassis, allowing you to perform normal take-off and landing in an airplane with take-off and mileage, respectively.

The vertical take-off and landing is provided by eight ED with lifting two-bladed propellers mounted in pairs and coaxially at the ends of two longitudinal beams mounted under the center section of a high wing. After moving to horizontal flight by plane, the lifting propellers stop and are forcibly fixed in the “blades along the stream” position, reducing drag.

The adopted technical solutions have eliminated some of the shortcomings of the above configurations. In particular, the use of separate power plants for vertical take-off and landing and for horizontal flight facilitates the achievement of high efficiency of both lifting and mid-flight propellers. The location of the longitudinal beams under the center wing does not violate the geometry of the upper surface of the wing, which reduces the loss of lift and aerodynamic quality in horizontal flight.

The disadvantages of this VTOL are the following layout features:

- the presence of a marching power plant in the nose of the fuselage makes it difficult to place a payload here;

- the placement of the marching power plant inside the rear of the fuselage makes it difficult to maintain, complicates the layout of the tail, requires special structural measures to organize engine cooling by supplying air from the external air intakes through curved channels inside the fuselage, which impairs production technology;

- the shape of the wing in plan, consisting of a rectangular center wing and trapezoidal consoles of small narrowing, having a trailing edge with a reverse sweep, makes it difficult to simultaneously fulfill the conditions for optimal position of the CM for the stages of GDP and horizontal flight;

- due to the non-optimal wing shape in plan, the front lifting screws are installed with a large extension forward relative to the front edge of the wing, which increases the length, weight and resistance of the longitudinal beams;

- the coaxial arrangement of the lifting screws reduces the overall efficiency of the lifting power plant and increases the energy consumption at the stages of vertical take-off and landing;

- the location of four of the eight lifting screws above the longitudinal beams increases the energy loss from blowing the beams at the stages of vertical take-off and landing, as well as the loss of lift in horizontal flight, since the aerodynamic trail from these screws violates the normal flow around the upper surface of the wing;

- a pushing screw located in the rear of the fuselage is not protected from touching the surface of the runway during take-off and take-off run, which reduces flight safety;

- landing gear have a large height, therefore, make a significant contribution to drag;

- the lack of wing mechanization increases the minimum speed of horizontal flight in an airplane, and this increases the energy consumption at the stages of acceleration in the air after vertical take-off and braking before vertical landing.

When creating a utility model, the task was to develop a simple and reliable aircraft for vertical take-off and landing, which would combine the advantages of a quadrocopter at the stages of vertical take-off and landing with the advantages of a normal-mode aircraft in horizontal cruise flight.

The solution to this problem is achieved by the fact that the wing cantilevers and the tail of the VTOL have straight non-swept trailing edges, the tail is made according to the inverted V, the axis of rotation of the ailerons, flaps and rudders located on the trailing edges of the wing and tail, are perpendicular to the longitudinal axis of the aircraft, the propulsion engine the propeller is mounted in the engine nacelle above the rear of the fuselage.

The front and rear landing gear are connected by skis.

The front and rear landing gear are connected by floats.

In FIG. 6 shows three projections and a general view of a VTOL aircraft.

The aircraft consists of a fuselage 1 with a high wing 2 large elongation. The wing has no transverse V and twist, consists of a rectangular center section 3 and trapezoidal consoles 4 with a narrowing η≈2.

Due to the narrowing and straight non-sweeping trailing edge, there is a slight sweep along the leading edge. For roll control, the outer parts of the trailing edge of the consoles are equipped with ailerons 5. The rest of the trailing edge of the consoles is mechanized in the form of flaps 6. Similar flaps 7 are located along the trailing edge of the center section. Both ailerons and flaps have rotation axes perpendicular to the longitudinal axis of the VTOL aircraft.

Ensuring GDP regimes is entrusted to a lifting power plant, consisting of two longitudinal beams 8, suspended under the ends of the center section 3, and four ED 9 mounted on them with two-bladed lifting propellers 10 located only under the beams. On a planned projection, the disks of the front and rear lifting screws form the same gaps with the front and rear edges of the wing, respectively. After moving to a horizontal flight by plane, the lifting propellers stop and are forcibly fixed in the “blades along the stream” position.

The thrust in a horizontal flight in an airplane is ensured by a marching propulsion system consisting of an engine 11 rotating a pushing propeller 12. The engine is mounted in a nacelle 13 located directly above the rear of the fuselage.

The tail unit consists of two trapezoidal consoles 14 located in the form of an inverted "V". The trailing edges are straight, non-arrow-shaped are occupied by the steering surfaces 15 with rotation axes perpendicular to the longitudinal axis of the VTOL.

VTOL is equipped with a four-wheeled chassis 16, which provides takeoff and mileage during takeoff and landing in an airplane.

The technical effect of the proposed utility model is achieved by the fact that:

1. Two longitudinal beams with a lifting power unit, suspended under the ends of the center section, leave the upper surface of the wing undistorted, which reduces the loss of lifting force in horizontal flight.

2. The location of the propellers only under the beams reduces the losses from the airflow of the beams at the stages of vertical take-off and landing, and also reduces the loss of lift in horizontal flight, since the perturbed aerodynamic trail from the propellers passes under the wing without disturbing the flow around the upper surface.

3. The wing shape in plan, consisting of a rectangular center wing and trapezoidal consoles, provides a better approximation to the ellipse compared to a simple trapezoid and, at the same time, simplifies the production technology compared to an ellipsoidal wing. Also, the simplification of production is facilitated by the absence of twist and a transverse V wing.

4. The rectangular shape of the center section is the best to provide maximum torsional rigidity, which is necessary to absorb the loads from the longitudinal beams of the lifting power plant.

5. The adopted form in terms of consoles, in the form of trapezoids with an arrow-shaped front and straight non-arrow-shaped trailing edges, in combination with a large elongation of the wing, facilitates the simultaneous fulfillment of the conditions for optimal position of the CM for the stages of GDP and horizontal flight. This allows you to reduce the forward extension of the front lifting screws, to reduce the length of the longitudinal beams of the lifting power plant, to reduce their weight and resistance in horizontal flight.

6. Direct non-arrow-shaped trailing edges of the wing and tail provide maximum efficiency of mechanization and steering surfaces.

7. The perpendicularity of the axis of rotation of the mechanization and the steering surfaces of the longitudinal axis of the VTOL simplifies the design, improves production and operational manufacturability.

8. The location of the tail consoles in the form of an inverted “V” protects the thrust propeller of the propulsion system from touching the runway during take-off take-off and landing with mileage.

9. The location of the engine marching power plant in the nacelle above the rear of the fuselage:

- simplifies engine cooling;

- facilitates maintenance and modernization of the power plant;

- allows to reduce the height of the landing gear and / or increase the diameter of the pushing screw;

- frees up space inside the fuselage for the layout of the tail and servo steering surfaces;

10. The presence of a wheeled chassis allows, in addition to GDP regimes, to perform both conventional take-off and landing on an airplane, with take-off and mileage, respectively, and shortened when there are necessary conditions for this. This broadens the range of possible applications of VTOL and increases its transport efficiency by reducing take-off energy costs and / or increasing payload weight. In addition, the ability to land on an airplane improves flight safety in the event that vertical landing is not possible.

11. The use of a four-support chassis with two nose supports instead of the traditional three-support with one nose support provides

- improving the stability and controllability characteristics when moving on the ground due to the doubled area of the supporting surface;

- reduction of aerodynamic drag in the case of fixed gear due to the reduction of the frontal projection area;

- ease of cleaning in the lateral tides of the fuselage in the case of retractable landing gear;

- increased margin of safety in case of rough landing;

- ease of upgrading to ski or float options;

- the ability to unify the design of the front and main supports, which reduces the cost of development, improves the manufacturability of production, reduces operating costs.

Claims (3)

1. Aircraft of vertical take-off and landing, consisting of a fuselage, a high wing, including a rectangular center section plan in plan and trapezoidal consoles, two longitudinal beams fixed under the center section to the left and right of the plane of symmetry of the aircraft, mounted on the front and rear ends of the beams of lifting propellers with vertical axes of rotation equipped with individual engines, tail V-tail, pushing marching screw located behind the tail and rotated the engine, and the four-wheeled landing gear, characterized in that the wing consoles and the tail have straight non-swept trailing edges, the tail is made according to the inverted V scheme, the axis of rotation of the ailerons, flaps and rudders located on the trailing edges of the wing and tail are perpendicular to the longitudinal the axis of the aircraft, the engine of the propulsion propeller is mounted in the engine nacelle above the rear of the fuselage. 2. Aircraft vertical take-off and landing according to claim 1, characterized in that the front and rear landing gear are connected by skis. 3. The aircraft vertical take-off and landing according to claim 1, characterized in that the front and rear landing gear are connected by floats.

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