RU2720746C1 - Rotorcraft - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to the field of aviation, particularly to the rotorcrafts designs. Rotorcraft comprises fuselage including rotary tail beam, front and rear wings secured on fuselage, engine groups each including motor and propeller arranged in tricopter configuration. Two air screws are fixed on ends of front wing, one air screw is fixed on tail boom. Front and rear wings are made in tandem pattern, wherein value of wing carry-over is equal to -90 % to -400 % of average aerodynamic chord. Angle of installation of front and rear wings is from 2° to 10°. Fore wing extension is not less than 3, rear wing extension is not less than 4. Angle of front motors front engine rotor motors clearance is 10 to 45 degrees.

EFFECT: higher lift of aircraft.

7 cl, 4 dwg, 1 tbl

Description

The technical solution relates to the field of aviation, in particular, to the design of rotorcraft.

The prior art such hybrid solutions are known, for example, quadplein, which is an airplane on which four vertical propellers are installed, providing only vertical flight. The main disadvantage of the quadplen diagram is the instability in lateral and rear winds at low speeds due to the high windage of the wings and the weak rotor-motor group of vertical flight, which lacks the power to fend off changes in the air environment.

Known unmanned rotorcraft containing two front wing consoles, each of which includes a movable and fixed parts and two rear wing consoles. Two screws are installed on the moving parts of the front wing, the axes of which are directed horizontally, and one screw with a vertically directed axis is installed in the rear part. The main body of the device contains a control unit, a communication unit, a sensor system, a GPS receiver. US patent for the invention No. 9709993, IPC B64C39 / 02; G05D1 / 00; G05D1 / 10, published July 18, 2017.

The disadvantages of this technical solution are the lack of a tail boom rotation function (such a device does not have sufficient maneuverability) and the wing design, in which the device does not have sufficiently high aerodynamic qualities.

In addition, for the vertical take-off of the device, so that all the screws accept the vertical axis, it is necessary to rotate the movable parts of the wings by 90 ⁰ . The design at the same time loses part of its lifting force.

A technical solution is known, selected as the closest analogue, which is an aircraft of vertical take-off and landing, including a fuselage with a tail boom, screws connected to the engines, forming a tricopter pattern. This unit also includes front and rear wings, with the rear wing mounted below the front. An automatic screw control unit is provided in the apparatus for ensuring maneuverability, and a system for ensuring a safe landing. Patent Application FR No. 2830839, IPC: B64C29 / 00, published April 18, 2003.

Distinctive features of the proposed solution are the tandem arrangement of the front and rear wings, with a negative value of the extension of the wing.

 In the known technical solution, the rear wing, in size and structurally, differs significantly from the front and due to its design does not participate in the creation of lifting force. In addition, it is below the level of the front wing. This design of the wings does not provide a sufficiently high aerodynamic performance.

The technical result of the claimed technical solution is manifested in improving the aerodynamic properties of the device due to the tandem wing scheme, in which, due to the placement of the front wing below the rear level, the mutual influence of the wings on each other is reduced, which ensures an increase in the lifting force of the device.

The technical result is achieved by the fact that in a rotary-wing aircraft containing a fuselage, including a tail boom, rotatable, front and rear wings mounted on the fuselage, rotor-motor groups, each of which includes a motor and propeller mounted in a tricopter configuration, while two propellers are fixed at the ends of the front wing, one propeller is mounted on the tail boom, the front and rear wings are made in tandem pattern, while the value of the wing offset is negative. The extension of the wing can be equal to from -90% to -400% of the average aerodynamic chord. The angle of installation of the front and rear wings can be from 2 ⁰ to 10 ⁰ . The elongation of the front wing can be at least 3, the lengthening of the rear wing can be at least 4. The angle of mowing of the engines of the propeller group of the front wing can be from 10 ⁰ to 45 ⁰ . The propeller can be mounted on the tail boom above or below it.

In order to describe the claimed technical solution, the following definitions are used.

Propeller group - a propeller mounted on the axis of rotation of the motor and driven by rotation of the axis of the motor.

Tandem wing pattern - a pattern in which two wings, designed to create lift, are located one after the other and spaced apart along the height of the fuselage.

Tricopter configuration - the configuration of an aircraft that performs flight and maneuvering in the air using three rotors, each of which is driven by a separate motor (engine).

Main rotor - a propeller with a vertical axis of rotation, or with a axis of rotation close to the vertical (with a deviation of an angle not exceeding 45 ⁰ ), providing lift to the rotorcraft, allowing controlled horizontal and vertical flight and vertical take-off and landing .

Wing removal - placing one wing in front of another. The wing extension is considered positive when the upper wing is in front, and negative when the lower wing projects forward. The wing extension is measured as a percentage of the MAR (average aerodynamic chord) protruding forward of the wing.

The average aerodynamic chord of the wing (SAX) is the chord of a rectangular wing that has the same area as the wing, the total aerodynamic force and the position of the center of pressure (CP) at equal angles of attack.

The central wing chord is the wing chord in the base plane of the aircraft.

The base plane of the apparatus is the plane of the basic coordinate system of the aircraft, with respect to which most elements of the aircraft are located symmetrically to the left and right.

The angle of the wing - the angle between the central chord of the wing and the base axis of the aircraft.

Wing lengthening is the ratio of the wing span to its average aerodynamic chord.

Mowing angle of the motor - the angle of the longitudinal inclination of the axis of the motor (coincides with the axis of the propeller), relative to the vertical.

Rotary-wing aircraft, being hybrids of copters and aircraft, combine the advantages of both. They have the ability to hover over the object, maneuverable in flight, while having a greater range, compared with copters.

The front and rear wings, arranged in a tandem pattern, contribute to the achievement of optimal aerodynamic parameters, allow to obtain a large bearing surface area. The advantage of tandem wings compared to non-tandem wings (a conventional biplane) is the reduced mutual influence of the wings on each other (reduction of the negative redistribution of air flow pressure and the influence of the satellite flow from the front wing to the rear wing, which reduces the lifting force of the rear wings). As a result, the lifting force acting on the device is significantly higher, and the aerodynamic drag is significantly lower compared to the biplane.

Thanks to the rotatable tail boom, the device can perform turns and maneuver in flight along an arc with a small radius distance due to a change in the thrust vector of the tail propeller.

With a negative wing extension, that is, when the front wing is located below the rear level, the mutual influence of the wings on each other is reduced, minimizing the interference of the flow incident on the rear wing and the satellite flow of the front wing. It was experimentally established that the optimal and permissible values of this indicator are in the range from -90% to -400%. In the design model with a wing offset below the -90% limit, interference arose that led to a deterioration in the aerodynamic performance of the device, while a wing extension above the -400% limit unreasonably exceeded the fuselage length in front of the wing span, and as a result, the weight of the device and to the deterioration of its aerodynamic characteristics. With a wing extension of -115%, the aircraft showed stable flight flight tests.

The angle of installation of the front and rear wings, equal from 2 ⁰ to 10 ⁰ , ensures maximum aerodynamic quality of the front and rear wings, respectively, at speeds close to cruising. It was experimentally established that the angle of installation of any of the wings is less than 2 ⁰ will lead to a lack of lift of the apparatus, while an increase in this angle to more than 10 ⁰ will cause a large drag of the aircraft and a stall from the wing.

The elongation value of the front wing is at least 3, and the rear wing is at least 4, helps to reduce inductive resistance, and also provides the optimal size of the end chords of the front wing, for installing engine brackets. Important in the design of the apparatus is the mowing angle of the front wing motors. Finding its indicator in the range from 10 ⁰ to 45 ⁰ allows you to achieve optimal aerodynamic characteristics of the device. It was experimentally established that the angle of installation of the propeller less than 10 ⁰ leads to insufficient horizontal thrust of the apparatus, and more than 45 ⁰ leads to a deterioration in the efficiency of the propeller, associated with an increase in the influence of the incoming flow.

The tricycle propeller scheme in combination with the tandem arrangement of the wings with the engine mowing in the claimed range allows vertical take-off and landing of the device, hovering in place, as well as horizontal flight on the wings, creating a horizontal projection of the thrust vector by cutting the propeller axis forward, which does not require the presence of additional horizontal pushing or pulling propellers, as well as the mechanical rotation of screws, wings or nacelles, does not require a swashplate.

Installing a propeller on the tail boom above it gives greater propeller safety during take-off and landing due to the fact that the risk of propeller contact with surrounding objects is reduced. The installation of a propeller on the tail boom below it gives a large lifting force, due to the lack of screening of the flow of the propeller thrown by the propeller itself.

The claimed technical solution is further explained with the help of figures, which conventionally presents one of the possible options for the performance of a rotorcraft.

In FIG. 1 shows a top view of a rotorcraft.

In FIG. 2 shows a side view of a rotorcraft.

In FIG. 3 is a plan view of the front wing of a rotorcraft.

In FIG. 4 is a plan view of a rear wing of a rotorcraft.

In FIG. Figures 1-4 show a rotary-wing aircraft (1) containing a fuselage (2), a tail boom (3), a front wing (4) and a rear wing (5), mounted on the fuselage (2), two propellers (6) of the propeller groups front wing (4), one propeller (7) of the propeller group of the tail boom (3).

The figures show the characteristics of a rotorcraft (1):

- wing extension - T;

- the angle of installation of the front wing (4) - α.p .;

- the angle of installation of the rear wing (5) - αz.k .;

- front wing span (4) - Lp.k .;

- middle chord of the front wing (4) - β.p .;

- the span of the rear wing (5) - Lz.k .;

- middle chord of the hind wing (5) - βz.k .;

- mowing angle of the front engine (6) - αd;

- mowing angle of the rear motor (7) - αz.d.

Next, with reference to the figures, the design of a rotorcraft (1) is described.

The rotorcraft (1) contains the fuselage (2), the tail boom (3), the front (4) and rear (5) wings, mounted on the fuselage (2). At the ends of the front wing (4), propellers (6) are installed. A rotary propeller (7) is mounted on the pivoting tail boom (3). In this case, the propellers (6) and (7) are installed in a tricopter configuration.

 The wings (4) and (5) of the apparatus (1) are made in a tandem pattern, while the front wing (4) is located below the rear wing (5), that is, the wing extension is negative and is from -90% to -400%. Preferred is a design with a wing offset of -109%.

Angle installation of the front wing (4) of the claimed apparatus (1) is from 2 to 10 ⁰ . The angle αz.k. has the same range. installation of the rear wing (5). In a preferred embodiment, the angle αp to the installation of the front wing (4) is 4.8 ⁰ , the angle αz.k. setting the rear wing (5) is 4 ⁰ .

The extension of the front wing (4), that is, the span ratio L. of the front wing (4) to the middle chord β.p. front wing (4) not less than 3. Elongation of the rear wing (5), respectively, not less than 4.

Angles αd, αw the longitudinal slopes of the axes of the propellers (6), (7) relative to the vertical are from 10 ⁰ to 45 ⁰ . The optimal design of the apparatus with angles αd, αz.d. longitudinal slopes of the axes of the propellers (6), (7) relative to the vertical, equal to 15 ⁰ .

A rotorcraft (1) may also include a landing gear and means for securing a payload, such as a camera, thermal imager, etc.

All the claimed parameters and characteristics of the apparatus (1) were established by experimental and theoretical methods. The permissible limits are selected based on the conditions for achieving the best aerodynamic characteristics while maintaining the general design features (tricopter configuration of propellers (6), (7) in conjunction with the tandem wing pattern (4) and (5)). The established necessary data are listed in Table 1.

Table 1

Parameter / Characteristic Lower limit Optimal value Upper limit Note wing extension -90% ...
with values of removal from -50% to -90%, energy consumption decreases slightly. With values from -90%, energy consumption becomes significantly less. -115%
minimum value of energy consumption. ... -400%
at values from -115% to -400%, power consumption increases. With values over -400%, energy consumption is growing even more significantly. As part of the research, flights were carried out with devices with a drift value of from -50% to -500% with energy consumption measured while flying at a constant speed, with the same speed for all experiments. The wing extension from 0% to -50% has not been investigated, since the propellers located on the front wing are close to the rear wing or partially overlap the surface of the rear wing, interfering with the normal flow around the wing and the operation of the propellers themselves. α.p. 2 ° ...
at values of from 0 ° to 2.0 °, energy consumption is reduced slightly. At values from 2.0 °, power consumption becomes significantly less. 4.8 °
minimum value of energy consumption. ... 10 °
power consumption is increasing. At values from 10.0 °, energy consumption increases even more significantly, there are vibrations associated with turbulence and a partial stall of the flow from the wing. Within the framework of the research, flights of vehicles with a value of α.p. from 0 ° up to 12 ° with the measurement of energy consumption when flying at a constant speed, with the same speed for all experiments. αz.k. 2 ° ...
at values of a.s. from 0 ° to 2 °, energy consumption is reduced slightly. At values from 2 °, power consumption becomes significantly less. 4 °
minimum value of energy consumption. ... 10 °
at values from 4 ° to 10 °, energy consumption increases. At values from 10 °, energy consumption increases even more significantly, vibrations associated with turbulence and partial stall of the flow from the wing appear. Within the framework of the research, flights of vehicles with a value of a.s. from 0 ° up to 12 ° with the measurement of energy consumption when flying at a constant speed, with the same speed for all experiments. Lp./
β.p. 3
when lengthening less than 3, energy consumption is increased due to the large drag of the wing.
Excessive shading of the airflow from the front propellers also occurs. - - With an elongation of more than 3, the shading of the air flow from the front propellers is minimal, and the size of the end chord is optimal for the design of the engine bracket. L.s./
βz.k. 4
when lengthening less than 4, energy consumption is increased due to the high drag of the wing and unjustified weighting of the wing structure. - - With an elongation of more than 4, the inductive resistance is significantly lower. αd 10 ° ...
at a value of less than 10 °, energy consumption does not change and approximately equals the energy consumption when hanging. With an angle of 10 ° or more, power consumption is significantly reduced. 15 °
minimum value of energy consumption. ... 45 °
at values from 15 ° to 45 °, energy consumption increases, but at the same time remains significantly lower than the energy consumption when hanging. With an angle of more than 45 °, energy consumption increases even more significantly. As part of the research, flights were carried out with devices with a mowing angle αd from 5 ° to 60 ° with the measurement of energy consumption when flying at a steady speed. a.s.d. 10 ° ...

at a value of less than 10 °, energy consumption does not change and approximately equals the energy consumption when hanging. With an angle of 10 ° ^{or more,} power consumption is significantly reduced. 15 °
minimum value of energy consumption. ... 45 °
at values from 15 ° to 45 °, energy consumption increases, but at the same time remains significantly lower than the energy consumption when hanging. When the value of the angle 45 ^{of the} power consumption increases even more significantly. Within the framework of the research, flights were carried out with the mowing angle α s.d. from 5 ° to 60 ° with the measurement of energy consumption when flying at a steady speed.

One of the preferred uses of the claimed rotorcraft (1) is shown below by example.

The apparatus (1) can be used in industry for aerial and video shooting, thermal imaging from the air as an unmanned aerial vehicle. With it, you can monitor territories and work processes, diagnose the state of infrastructure and industry: buildings and structures, pipelines, power lines, roads, equipment, etc.

Due to the vertical take-off and landing, the apparatus (1) does not require a special platform or device for take-off, a 2-square-meter area is sufficient. m. The ability to hover over a point helps to consider the object in more detail. Maneuverability allows you to fly in a confined space and not spend charge on extra distances in turns. The flight range of the device allows you to fly over large areas and extended objects.

In horizontal flight, the apparatus (1) leans forward so that the angle between the plane of rotation of the propellers (6), (7) and the velocity vector becomes larger. So the propellers (6), (7) create a horizontal projection of the thrust and the apparatus (1) flies horizontally.

In this case, the resistance of incident flows to the rear wing (5) is minimized due to its location above the level of the front wing (4).

By rotating the tail boom (3), the apparatus (1) performs turns and maneuvers in flight. By increasing or decreasing the speed of rotation of the screws (6) and (7) relative to each other, the apparatus (1) changes the pitch angle.

The presented figures, the description of the design and use of the rotorcraft do not exhaust the possible options for performance and do not limit in any way the scope of the claimed technical solution. Other options for execution and use in the scope of the claimed formula are possible. Depending on the purpose, the rotorcraft (1) can be made in different sizes, colors and configurations.

The rotorcraft has the parameters of minimum noise, minimum electromagnetic interference, the relative simplicity of the arrangement of high-frequency elements due to the rear wing, which does not have power current-carrying elements. It also simplifies optimization for various schemes of operation of aerodynamic planes and increases the availability of variations of structural and power schemes of units. The inventive tricopter aerodynamic design of a rotorcraft with fixed tandem wings is the most optimal for use in the design of a hybrid aircraft in transition and hybrid modes.

Claims (7)

1. A rotorcraft containing a fuselage, including a tail boom, rotatable, front and rear wings mounted on the fuselage, propeller groups, each of which includes a motor and propeller mounted in a tricopter configuration, while two propellers are fixed at the ends front wing, one propeller is mounted on the tail boom, characterized in that the front and rear wings are made in tandem pattern, while the value of the wing offset is negative. 2. A rotary-wing aircraft according to claim 1, characterized in that the wing extension is from -90% to -400% of the average aerodynamic chord. 3. The rotorcraft according to claim 1, characterized in that the angle of installation of the front and rear wings is from 2 ° to 10 °. 4. The rotorcraft according to claim 1, characterized in that the elongation of the front wing is at least 3, the elongation of the rear wing is at least 4. 5. The rotorcraft according to claim 1, characterized in that the mowing angle of the engines of the propeller groups of the front wing is from 10 ° to 45 °. 6. The rotorcraft according to claim 1, characterized in that the tail rotor propeller is mounted on top. 7. The rotorcraft according to claim 1, characterized in that the tail rotor propeller is installed from below.

Images