RU2757693C1 - Vertical take-off and landing aircraft with propellers on rotary wing flaps - Google Patents

Abstract

FIELD: aviation.SUBSTANCE: invention relates to the field of aviation, namely to design of vertical takeoff and landing aircraft. The vertical take-off and landing aircraft with propellers on rotary flaps contains the fuselage, wings, tail, power supply systems, navigation, flight control, electric propeller groups with controllers. The propeller groups are mounted on flaps that can rotate along the axis of wing trailing edge both vertically upwards during takeoff / landing or hovering, allowing propellers to rotate freely to create lift, and in a horizontal position during cruise flight.EFFECT: increase in flight qualities of the aircraft is ensured by reducing turbulence of air flows created by propeller-wing system.5 cl, 14 dwg

Description

Technology area

The invention relates to aeronautical engineering, specifically to combined aircraft with the properties of an aircraft and a helicopter, namely to multicopters having wings with segments (flaps) capable of turning relative to the trailing edge of the wing, on which pushing propellers (propellers) are installed, creating a lift when rotating horizontally in take-off / landing mode, and thrust when rotating in a vertical plane during cruise flight. A distinctive feature of the proposed multicopters is the location of the center of rotation of the propellers in the immediate vicinity of the trailing edge of the wing, outside the zone of the turbulent wake formed behind the wing.

The technical result of the invention is to improve the aerodynamic qualities of the aircraft propeller-wing system.

Prior art

The main advantages of multicopters are the possibility of vertical take-off / landing, hovering at a point and high maneuverability, the disadvantages are high power consumption with limited energy capacity of batteries and low speed during horizontal flight, which limits the duration and range of flight, respectively.

In order to eliminate the aforementioned disadvantages of multicopters, various versions of vertical take-off and landing hybrid aircraft (AC) are being actively developed, which have in their design both rotary propellers, which create a lift or thrust force depending on the position of the plane of rotation of the propellers, and wings that provide additional lift in cruise flight mode.

Below are analogs of the claimed aircraft design, reflecting the currently known concepts of hybrid multicopters designed for flights at higher speeds and over long distances.

1. Rotary propellers outside the wing plane.

In the patent US 10474167 declared the design of the aircraft vertical takeoff and landing with propellers in the rings, turning in front of the wing (Fig. 1).

The propellers in the rings are located so that when the propellers rotate in the horizontal plane during takeoff / landing or hovering, the air flows generated by them do not cross the wing surfaces. The disadvantage of the design is the inevitable creation of turbulence in the air flow in front of the wing during horizontal flight, which reduces the flight performance of the aircraft.

Also known is the design of the aircraft vertical take-off and landing US 10773802 with horizontally fixed wings and rotary propellers on the rods (Fig. 2). The booms are long enough to prevent the wing planes from blocking the air currents created by the propellers. The propellers in front of the wings create less turbulence during horizontal flight than the propellers in the rings in the previous design, however, the above disadvantage is not completely eliminated. In addition, the rotation of the propellers on the rods causes the impact on the fuselage of the moments of impulse and vibrations, which are the higher, the longer the rods.

2. Swivel arched wing with propellers in the arches.

The aforementioned drawback of designs in which the propellers in front of the wing and the propellers on the rods create airflow turbulence and vibration is absent in the so-called arched type wings shown in FIG. 3. In the patent US 2018/0086447 it is proposed to install propellers in the arches of the wings. The planes of rotation of the propellers do not rotate relative to the wing, and it is proposed to rotate the wings to switch from the vertical take-off / landing mode to the cruise flight mode.

The disadvantage of the design is a decrease in the lifting force of the wing due to a decrease in its flat part, as well as the complication of the aircraft design and increased energy costs for turning the wings.

3. Swivel propellers on the side edge of the wing.

As an example of the design of an aircraft with rotary propellers at the ends of the wing, patent US 10850833 (Fig. 4) can be cited. When the rotor rotates in horizontal planes, the air flows from the propellers are partially intersected by the wing planes. However, the diameters of the propellers are chosen large enough so that the area of their circle of rotation is greater than the area of intersection with the wing.

Known similar aircraft designs with rotary screws at the ends of the wings of Joby Aero (US 2020/0333805, US 2020/0317328), Bell Helicopter (US 10414483) and other companies.

A common disadvantage of such designs is a decrease in the lift of the propellers due to the wing partially blocking the air flow generated during takeoff / landing and hovering.

4. Swivel wing with propellers on the leading edge of the wing.

A ^ 3 Airbus has patented aircraft designs with rotatable wings, on the leading edges of which propellers are fixed (US 2019/0291862, US 2019/02918636, US 2020/0164976).

The basic design of such aircraft is shown in FIG. 5. The propellers in the rings are located on the wings in pairs and rotate in opposite directions for mutual compensation of moment of momentum and facilitating the rotation of the wing.

The disadvantage of the designs is that the propellers rotating in front of the wing create turbulence in the air flow, which leads to a decrease in the efficiency of both the propellers and the wing, additional energy losses, increased noise and vibration, and, in general, reduces the aerodynamic qualities of the aircraft.

US patent 10562620 proposes a vertical take-off and landing aircraft design with deflectable wings, on the leading edges of which are fixed propellers located in aerodynamic rings (Fig. 6). The rings increase the efficiency of the screws and protect them from accidental mechanical damage, but they also do not eliminate the above disadvantages.

The aircraft design with rotatable wings, on the leading edges of which propellers are fixed, was patented by Kitty Hawk (US 10336448). This design differs from the above designs of the A ^ 3 Airbus aircraft in that the propellers on the leading edge of the wing fold down during cruise flight. The screws remain open and pull only at the ends of the wing (Fig. 7).

The lift during takeoff / landing and hovering is created by all the pulling propellers, and the thrust in cruise flight is created only by the propellers located at the ends of the wings. The rest of the propellers located on the leading edge of the wing are folded in the cruise flight mode so as not to create turbulent flows in front of the wing.

This partially eliminates the above-mentioned disadvantages of an aircraft with propellers on the leading edge of the wing. The propellers folded in cruise do not create turbulence, vibration and noise, but they also do not create thrust. In addition, the disadvantages inherent in aircraft with rotary propellers on the side edge of the wing, noted in the previous section, remain.

5. Fixed wing with rotary propellers at the trailing edge of the wing.

An alternative solution is to locate the swivel screws behind the wing. Known patent US 6732972, which proposes to place the rotatable propellers behind the wing. At the same time, the wings of the aircraft are rigidly attached to the fuselage, and vertical take-off / landing or cruise flight is carried out by turning the propellers to rotate in a horizontal or vertical plane, during take-off / landing and during cruise flight, respectively. A general view of such an aircraft is shown in Fig. 8a.

A distinctive feature of the proposed design is that for each rotary propeller, the center of rotation is located in the plane of the wing, and segments are cut out in the wing to ensure free rotation of the propeller in the horizontal plane, as shown in Fig. 8b, p. According to US Pat. No. 6,732,972, the cut segment should not be larger, but preferably less than half of the circle swept by the propeller. At the same time, the centers of rotation of the propellers are offset from the edge of the wing so that during horizontal rotation the propeller does not intersect with the wing.

A positive effect is that in the proposed design, the wing does not interfere with the propeller during takeoff / landing and hovering. At the same time, segments cut from the wing reduce the surface area that creates lift. In addition, the patent does not analyze the effect of notches on the formation of vortices and turbulence of the air flow behind the wing edge during cruise flight. This patent is a close analogue of the claimed invention.

Also known is the design of the aircraft company Kiity Hawk (US 10144503, US 10981648) with wings fixedly attached to the fuselage, and rotary propellers fixed either on the side edges of the wing (front wing in Fig. 9) or on the trailing edge of the wing (main wing in Fig. 9). At the same time, the propellers are attached to the trailing edge of the wing through pylons of such length that during takeoff / landing the wing plane is not crossed by the propellers rotated to rotate in the horizontal plane.

When the rotatable propellers are located behind the wing, the disadvantages inherent in aircraft with propellers on the leading edge are eliminated, namely, the creation of turbulence by the propellers in front of the wing in cruise flight. However, the propellers located behind the wing themselves find themselves in a zone of turbulence, the so-called wake region, which occurs as a result of the breakdown of the air flow around the wing from the wing edge.

Patent U10981648 can be considered as a prototype of the claimed invention.

The aim of the invention is to find a constructive solution in which the mutual negative influence of the propeller and the wing is minimized in the "propeller-wing" system, and the system itself achieves extremely high aerodynamic parameters.

Brief Description of Drawings

FIG. 1. Multicopter with propellers turning in front of the fixed wing in aerodynamic rings. The position of the propellers: a) during cruise flight, b) during takeoff / landing and hovering. (Prior Art, US 10474267, 12.11.2019).

FIG. 2. Multicopter with rotatable propellers on brackets in front and behind the fixed wing. (Prior Art, US 773802, 15.09.2020).

FIG. 3. A multicopter with arched wings and air propellers built into the arched openings. (Prior Art, US 2018/0086447, 05/29/2018).

FIG. 4. A multicopter with fixed wings and pivoting propellers at the ends of the wings. The position of the propellers: a) during cruise flight, b) during takeoff / landing. (Prior Art, US 10850833, 12.08.2014).

FIG. 5. Multicopter with rotatable wings and propellers rigidly fixed on the leading edge. The aircraft is shown in cruise mode. (Prior Art, US 2020/0164976, 28.05.2020).

FIG. 6. Multicopter with rotating wings and propellers rigidly fixed on the leading edge in aerodynamic rings. The aircraft is shown in cruise mode. (Prior Art, US 10562620, 02/18/2020).

FIG. 7. Multicopter with rotatable wings and propellers rigidly fixed on the leading edge, folding in cruise flight. The aircraft is shown in modes: a) takeoff / landing, b) cruise flight. (Prior Art, US 10336448, 06/07/2019).

FIG. 8. Aircraft vertical takeoff / landing with fixed wings, in which segments are cut out for rotating propellers installed behind the wing. (Prior Art, US6732972, 11.05.2004).

Fig. 9. A vertical take-off / landing aircraft with fixed wings and pivoting propellers mounted on pylons at the rear of the wing. (Prior Art, US 10981648, 04/20/2021 - prototype).

FIG. 10. The relative position of the wing, flap and propeller during takeoff in the projections: a) from above, b) from the side, c) from behind. The relative position of the wing, flap and propeller during cruise flight in the projections: d) from above, e) from the side, f) from behind.

FIG. 11. The relative position of the wing, flap and a pair of oppositely rotating propellers: in the projections: a) during takeoff (top view), b) in cruise flight (top view).

FIG. 12. Multicopter design with rotary flaps and propellers mounted on the trailing edge of the wings. Isometric view: a) in take-off / landing and hover modes, b) in cruise flight mode.

FIG. 13. Design of a multicopter with rotary wing parts, on which propellers are installed in aerodynamic rings. Isometric view: a) in take-off / landing and hover modes, b) in cruise flight mode.

FIG. 14. Multicopter design with rotary flaps and propellers mounted on the trailing edge of the wings at a height of half the propeller radius above the flap. View in take-off / landing and hover modes: a) isometric projection, b) side view. Cruise view: c) isometric view, d) side view.

Disclosure of the essence of the invention

The technical objective of the invention is to create a new design of a hybrid aircraft - a multicopter with improved flight characteristics relative to known analogues and prototype.

The solution to the technical problem consists in creating a multicopter with wings rigidly attached to the fuselage with flaps (segments) rotated along the axis of the trailing edge of the wing, on which pushing propellers are located.

The technical result of the invention consists in increasing the flight characteristics of the aircraft by reducing the turbulence of air flows in the area of the "propeller-wing" system and minimizing the mutual negative influence of the wings and propellers.

On the one hand, various versions of hybrid aircraft with vertical takeoff and landing are known, in which propellers or wings with propellers mounted on them turn, and the propellers are installed on the leading edges or at the ends of the wings. Examples of such aircraft are the above analogs.

On the other hand, various aircraft with rear-mounted pusher propellers are known, from the XP-56 military fighter to the modern ultra-efficient Celera-500 experimental aircraft.

It is known, chosen as a prototype, Kitty Hawk vertical takeoff and landing aircraft, with fixed wings and rotary propellers mounted on pylons on the rear side of the wing at a distance that prevents the wing from blocking the air flow from propeller rotation during takeoff / landing and hovering, that is at a distance not less than the radius of the propeller.

However, we are not aware of hybrid vertical take-off and landing aircraft with wing segments - flaps rotated along the axis of the trailing edge of the wing, on which push propellers are installed.

In the claimed invention, it is proposed to eliminate the air gap between the trailing edge of the wing and the propeller by placing the propeller as close to the wing as possible. Modern electric motors are several centimeters thick and make it possible to install propeller-driven groups on the trailing edge of the wing without the need to change the wing profile.

FIG. 10 schematically shows the projection of a fragment of a wing (1) with a semicircular flap (2), on which a propeller group with a propeller (3) rotating in a plane normal to the flap is rigidly mounted. The flap in the initial position is lowered to a horizontal position and forms a single aerodynamic body with the wing.

When the aircraft takes off, the flap (2) rises to a vertical position and opens a cutout in the wing, which allows the propeller (3) to rotate horizontally to create lift.

The relative position of the wing, flap and propeller during takeoff is shown in FIG. 10 a, b, and c, in top, side and back projections, respectively.

During cruise flight of an aircraft, the flap (3) is lowered to its original position, restoring the integrity of the wing as an aerodynamic body, and the propeller rotates in a vertical plane, creating thrust. In this case, the propeller is pushing. The relative position of the wing, flap and propeller during cruise flight is shown in FIG. 10 d, e, and f, in top, side and back projections, respectively.

The above option is not the only one possible. FIG. 11 shows a fragment of a wing (1) with a flap (2), on which there are two propeller-driven groups with propellers (3) rotating in opposite directions. Opposite rotation of the two propellers compensates for the moment of momentum, which makes it easier to turn the flap and reduces the mechanical effect of the propeller groups on it.

The relative positions of the wing, flap and propellers are shown in FIG. 11 in projections from above a and b during takeoff and cruise flight, respectively.

The rotatable flap may have the shape shown in FIG. 11 or other suitable shape, including the entire rear of the wing, of a width sufficient to rotate the propeller during take-off centered on the trailing edge.

FIG. 12-Fig. 14 shows projections of an aircraft with rotary flaps, on which propellers are installed, making up with the wing a single propeller-wing system proposed above.

The aircraft has two wings - the lower front main wing, consisting of the right and left floor of the wings, and the rear upper solid wing. In the proposed aircraft design, the wings are rigidly fixed relative to the body, and the flaps can be rotated from a vertical position during takeoff to a horizontal position when switching to a cruise flight.

The front wing is located behind the aircraft cockpit, which provides free access to the cockpit door and ease of boarding / exiting the aircraft, increases passenger safety due to the remote location of rotating propellers, and also reduces cabin noise during cruise flights. The location of the wings and propellers does not limit the view from the cockpit and does not interfere with the installation of observation and other equipment in the front of the aircraft.

The height of the lower wing of the aircraft standing on the take-off site is sufficient for the safety of the propeller blades when turning the wing. The risks of destruction of the pusher propeller in contact with the surface of the runway inherent in aircraft requiring takeoff roll are significantly reduced for aircraft with vertical takeoff and landing.

Adjacent propellers rotate in opposite directions to compensate for moment of momentum and reduce forces for turning the wing on which they are mounted. The profiles of the blades of adjacent propellers differ in such a way that they provide the same direction of air flows when rotating in opposite directions. The propellers are pushing and create lift during takeoff / landing and thrust during cruise flight.

The propellers are rotated by electric motors, which make up propeller groups with them. Electricity for powering the VMG motors is provided by storage batteries, hybrid electric generators with internal combustion engines, electrochemical generators based on hydrogen fuel cells, separately or in any combination.

The aircraft flight is carried out according to the program performed by the flight controller. Aircraft maneuvering is provided by control of the propeller rotation speeds in accordance with the commands given by the flight controller to the controller of each VMG.

FIG. 12 shows an aircraft with swivel flaps on the front main wing for each single propeller. Isometric projections of the aircraft are presented: (a) in take-off mode and (b) in cruise flight mode.

FIG. 13 shows an aircraft with rotary flaps on the front main wing for pairs of propellers rotating in opposite directions. The aircraft is presented in isometric projections: (a) in take-off mode and (b) in cruise flight mode. It is clear that propellers can be used without aerodynamic rings.

A distinctive feature of the propeller-wing system shown in FIG. 13 is that the propellers are enclosed in rings that protect the propellers and increase the aerodynamic properties of the propeller-wing system. The rings are rigidly fixed to the flaps and form a single structure with them.

The advantages of using aerodynamic rings are: 1) in protecting the propellers on the lower wing from destruction in case of accidental contact with the ground or hit by stones during takeoff / landing, 2) in increasing lift and thrust with a correctly calculated profile of the ring.

FIG. 14 shows an aircraft with the position of the centers of rotation of the propellers half a radius above the wing. When the center is above the wing, the propeller provides an increased speed of the air flow over the wing, prevents the boundary layer from separating from the wing and the formation of a return flow and vortices over the upper surface of the wing.

Claims (5)

1. A vertical take-off and landing aircraft with propellers on rotary flaps, containing a fuselage, wings, empennage, power supply systems, navigation, flight control, electric propeller-driven groups with controllers, characterized in that the propeller-driven groups are mounted on flaps that can rotate along the axis of the trailing edge of the wing both vertically upward during takeoff / landing or hovering, allowing the propellers to rotate unhindered to create lift, and into a horizontal position during cruise flight. 2. A vertical take-off and landing aircraft with propellers on rotary wing flaps according to claim 1, characterized in that the center of rotation of the propeller is in the plane of the wing in the zone prior to the formation of a turbulence zone in the wake behind the wing. 3. A vertical take-off and landing aircraft with propellers on rotary wing flaps according to claim 1, characterized in that two propellers with opposite directions of rotation are installed on the flap. 4. A vertical take-off and landing aircraft with propellers on rotary wing flaps according to claim 1, characterized in that the propellers are installed so that the center of rotation is above the plane of the wing at a distance of no more than the radius of the propeller. 5. A vertical take-off and landing aircraft with propellers on rotary wing flaps according to claim 1, characterized in that the propellers are mounted on the flaps in the aerodynamic rings.

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