RU168554U1 - High-speed combined helicopter (rotorcraft) - Google Patents

Abstract

The utility model relates to the field of aircraft construction, namely to rotary-wing aircraft. The technical objective of the claimed utility model is to increase the speed of the rotorcraft. The technical problem is achieved by the fact that the high-speed combined helicopter (rotorcraft) having a combined carrier system consisting of a coaxial rotor and a glider with horizontal and vertical plumage with controllable surfaces, a power plant consisting of a transmission (gears and shafts) and an engine, retractable in flight landing gear, sleep They are equipped with a wing located behind the axis of the shaft of the coaxial rotor equipped with controlled flaps, elevons and deflectable consoles and at least one engine, made combined and providing both the creation of propulsive jet thrust through the tail nozzle in all operational flight modes, and the drive with the possibility of changing the rotational speed of the coaxial rotor, while the horizontal controlled tail is located in front of the axis of the shaft of the coaxial rotor, and the vertical tail getting on the wing.

Description

The utility model relates to the field of aircraft construction, namely to rotary-wing aircraft.

The technical solution of the Ka-35D high-speed rotorcraft of the Kamov firm (Russia) is known (see Yu.E. Savinsky, Kamov. Creative biography of the designer of helicopters, POLYGON PRES Moscow 2003 p. 162), (and the high-speed coaxial helicopter S-97 Raider, created by ABC concept by Sikorsky (USA)).

The Ka-35D rotorcraft is a combined helicopter (rotorcraft) having combined carrier and propulsion systems. The combined carrier system consists of a wing and rotor screws transversely located at its ends. The combined propulsion system includes gas turbine engines that drive rotors, and turbojet engines mounted on the wing to create propulsive force.

The combined carrier and propulsion systems provide the rotorcraft with the possibility of vertical take-off and landing, hovering and the ability to switch to airplane flight modes at high speeds. The main part of the lifting force in airplane modes is created by the wing, and propulsion (propulsive) forces are created by jet engines.

Using the wing to unload the rotors with increasing rotor speed allows you to increase the speed of horizontal flight up to 550 km / h, increase aerodynamic quality and reduce the load in the carrier system.

On the Ka-35D rotorcraft, take-off, gas-turbine engines are used to take off the main rotors for take-off, landing and transition modes (from vertical to horizontal and vice versa), which are switched off in horizontal flight. In this case, in horizontal flight, the rotors begin to work in autorotation mode (self-rotation from the incoming flow), creating additional resistance. To improve the flight characteristics of the rotorcraft at high flight speeds, a decrease in the rotor speed of the rotors was applied.

The disadvantage of the technical solution adopted on the Ka-35D rotorcraft is the use of separate power plants (lift and propulsion), and the propeller autorotation mode in airplane flight modes, which limits the possibility of increasing the flight speed over 500 ... 550 km / h.

On the Ka-35D rotorcraft, with increasing flight speed, significant unloading of the propellers is required to ensure the operation of the propellers and increase the aerodynamic quality of the propeller-wing system. With increasing flight speed, the lifting force of the propellers should decrease. At the same time, with increasing flight speed, to ensure autorotation, it is necessary, at a given rotational speed of the screws, to increase their angle of attack, traction coefficient and, accordingly, the lift force of the screws. As a result, at flight speeds of more than 550 km / h, significant contradictions arise between the requirements for the values of the lift coefficient, which are necessary to ensure the autorotation mode, and the values necessary to ensure the stall characteristics and the operability and stability of the flywheel of the rotor blades. These contradictions prevent a further increase in flight speed when using autorotation mode on the rotors.

The Sikorsky high-speed coaxial helicopter is known (see Vertiflite November / December 2014, pp. 12-13; Popular Mechanics, December 2014, pp. 96-103), created according to the ABC concept. The helicopter provides for the use of so-called “rigid” coaxial rotors, which, according to the company, ensure the full use of the advancing blades in a symmetrical coaxial pattern, the ability to move the stall boundary on the retreating blades, reduce the flywheel movement of the blades and increase the bearing capacity and aerodynamic quality of the rotor. In this concept, a reduction in rotor speed is also contemplated. This concept ensures the achievement of a maximum flight speed of up to 450 km / h.

The S-97 high-speed coaxial helicopter has: a streamlined fuselage on which two three-bladed rigid rotors are located coaxially (on the same axis) to create lift; cockpit for two pilots located in the bow of the fuselage; tail unit, consisting of a horizontal stabilizer with deviated (controlled) surfaces, two vertical keels (washers) at its ends with rudders and a ventral vertical keel fairing; three-post flight retractable landing gear with two front main and one tail support; six-bladed pushing propeller of an adjustable pitch located in the rear of the fuselage and serving to create horizontal (propulsive) force. The power plant of the helicopter consists of gearboxes, shafts and one gas turbine engine, from which all the propellers are driven - both bearing and pushing propeller. The rotor bushings and the upper rotor shaft are covered with fairings.

The disadvantage of the technical solution proposed by Sikorsky is that, with increasing flight speed, bending moments acting in the plane of the rotor wave increase significantly, which requires significant weight expenditures when creating rotor blades, bushings and shaft to provide the necessary strength. In addition, in this technical solution, with an increase in vertical overload, the load increases significantly. The growth of loads with increasing flight speed and with increasing overload limits the possibilities of using this model for high flight speeds and when maneuvering with large overloads.

The translational speed of flight is entirely created by a six-blade pushing propeller of variable pitch.

The technical task of the proposed utility model is to enable a significant increase in the flight speed of a vertically take-off aircraft with at least one rotor to flight speeds significantly higher than that of the prototype (450 km / h), and to provide the possibility of significantly improving its maneuverability by such flight speeds.

The technical problem is solved due to the fact that a high-speed combined helicopter (rotorcraft) having a combined load-bearing system consisting of a coaxial rotor and a glider with horizontal and vertical tail with controllable surfaces, a power plant, consisting of a transmission (gears and shafts) and an engine, retractable in flight, the chassis is equipped with a wing that provides almost complete unloading of the rotor, regardless of how the blades are attached to the hub (“rigid” or hinged), and located behind the axis in a coaxial rotor equipped with controlled flaps, elevons and deflectable consoles and at least one engine, made combined and providing propulsive jet thrust through the tail nozzle in all operational flight modes, as well as a drive and the ability to control the speed of the coaxial rotor, while the horizontal plumage is located in front of the axis of the shaft of the coaxial rotor, and the vertical plumage is mounted on the wing.

Applying the new principle, which we called the “zero thrust concept (ZT - Zero Thrust)”, instead of creating a helicopter with a “rigid” coaxial rotor without a wing (S-97), it is proposed to create a coaxial rotorcraft (helicopter with a wing and a propulsive propulsion), which provides the opportunity almost complete unloading of the propellers by reducing thrust and revolutions and, accordingly, substantially reducing the effect of propellers on the aircraft’s energy. At the same time, the wing provides the necessary lifting force during flight with practically zero propeller thrust in all operational flight modes. The amount of power supplied to the screw must be sufficient to ensure stable rotation of the screws and speed control. In this case, the loads in the structural elements of the screws are significantly reduced. The flywheel movement is reduced, which additionally opens up the possibility of achieving subsonic flight speeds.

According to the ZT concept, reducing the speed of the propeller and its thrust to the minimum allowable values leads to a qualitative change in the characteristics of the aircraft. The flight data is determined solely by the aerodynamic characteristics of the airframe, and the rotorcraft essentially turns into an airplane.

The inventive utility model is illustrated by drawings, where:

FIG. 1 - General view of the rotorcraft;

FIG. 2 - Three projections of a rotorcraft.

The proposed utility model of a high-speed combined helicopter (rotorcraft) contains: a streamlined fuselage 1, in the bow of which there is a nose fairing 2, a crew cabin 3 with controls (cyclic step lever, common pitch lever, track control pedals); casing compartment 4; front horizontal controlled plumage (PGO) 5; located in front of the axis of the shaft of the coaxial rotor 7; located in the middle part of the fuselage fairing (boar) 6 of the coaxial rotor 7, including blades 8, bushings 9, fairings of the bushings 10, the control system of the screws 11 and the fairing 12 of the shaft of the upper rotor; a nacelle 13 with a combined power unit configured to reconfigure the rotational speed of the coaxial rotor 7, comprising at least one combined motor 14, providing both the coaxial rotor drive through the main gearbox and the creation of propulsive jet thrust through the tail nozzle 15; a wing 16 located behind the axis of the shaft of the coaxial rotor 7 and equipped with controlled flaps 17, elevons 22 and deflectable consoles 21; vertical tail 18 with rudders 19 mounted on the wing; retractable landing gear 20.

The proposed utility model of a high-speed combined helicopter (rotorcraft) works as follows.

The take-off of a high-speed combined helicopter (rotorcraft) is carried out by helicopter - vertically, using a coaxial rotor 7. To ensure vertical take-off, the combined engine 14 supplies the necessary power to the coaxial rotor 7 of the rotorcraft through the main gearbox. Moreover, the thrust of the combined engine 14 is minimal. Previously, the combined engine 14 is configured to provide take-off speeds of the coaxial rotor.

After a vertical take-off and, if necessary, fixing the hovering mode, either the necessary evolutions are carried out at low flight speeds (in accordance with the mission), or the transition to high flight speeds. To do this, by deviating 3 controls in the cockpit, the jet thrust of the combined engine 14 increases (using the provided excess power) and as the acceleration accelerates, when the required power decreases, the power supply to the coaxial rotor 7 automatically decreases while maintaining a constant speed . Acceleration is carried out with a positive pitch angle of a high-speed combined helicopter (rotorcraft), as a result of which, with increasing flight speed, the lifting force of the wing 16 increases. During the acceleration, the controlled flaps 17 and the deflectable wing consoles 21 are set to the flight position. Chassis 20 retracts.

With increasing flight speed, at speeds of more than 250 ... 300 km / h, a smooth reconfiguration of the rotational speed of the coaxial rotor 7 is carried out in the direction of decreasing its speed. Acceleration can be carried out both with climb and horizontally. As you accelerate with increasing lift of the wing 16, the lift of the coaxial rotor 7 decreases. When reaching flight speeds of 400 km / h and above, the rotational speed of the coaxial rotor 7 is set, which ensures optimal flight characteristics. At speeds of more than 400 km / h, the coaxial rotor 7 is unloaded to the minimum permissible value, while the creation of the necessary revolutions of the coaxial rotor 7 is ensured by automatically reconfiguring the speed of the output shaft of the combined engine depending on flight conditions, flight mass, speed, barometric altitude outdoor temperature.

In this flight mode on a high-speed combined helicopter (rotorcraft), a new principle is used, which we called the “Zero Thrust Concept (ZT - Zero Thrust)”, the essence of which is to ensure that the main rotor 7 is almost completely unloaded, regardless of the mounting method (“hard” or hinged) blades 8 to the sleeve 9. Coaxial rotors in this case have almost zero traction, low speed and resistance. The power loss on the drive of the rotor 7 is determined mainly by the loss to overcome the profile resistance, which with a decrease in speed and thrust of the rotor 7 is reduced. In this case, the rotors 7 have a small flywheel movement and loads, and have a small effect on the overall energy of the flight.

Further, the flight takes place in airplane mode, where the main lifting force is provided by the wing 16 with deflectable consoles 21.

The creation of the necessary vertical overload and maneuvering is carried out by increasing the lifting force of the wing 16 (by taking the cyclic pitch lever in the cockpit 3 “towards you”). In this case, to prevent the growth of the rotational speed of the coaxial rotor 7 and its thrust in excess of the permissible value, the automatic control system, or the pilot by means of the controls in the cockpit 3, additionally deflect down the controlled flaps 17.

The automatic control system with an increase in overload also provides an additional reduction in the total pitch of the coaxial rotors to prevent the growth of the thrust coefficient of the screws 7, with an acceptable change in speed. In this case, a predetermined overload is obtained with a moderate increase in the pitch angle (attack) and the rotational speed of the coaxial rotor 7. In order to maintain the flight speed when the controlled flaps 17 are deflected, the reaction thrust of the combined engine 14 can additionally increase.

Longitudinal control of a high-speed combined helicopter is carried out by changing the cyclic pitch of the coaxial rotors, the corresponding deviation of the front horizontal tail unit (PGO) 5, and the deviation of the elevons 22 on the deflectable wing consoles 21.

Transverse control of a high-speed coaxial combined helicopter is carried out by changing the cyclic pitch of the coaxial rotors and deflecting the elevons 22 on the deflectable wing consoles 21.

The control of a high-speed combined helicopter in the course is carried out by changing the differential total pitch of the coaxial rotors and deflecting the rudders 19 on the vertical tail 18 by means of the directional pedals in the cockpit 3. The gear ratio between changing the differential total pitch of the coaxial rotors and rudders is variable. At the same time, at speeds of more than 320 km / h, the change in the differential total pitch of the coaxial rotors is completely disabled.

After completing the task, the high-speed combined helicopter (rotorcraft) is braked to flight speeds of 250 ... 300 km / h with the output of the rotational speed of the coaxial rotor 7 at the take-off speed. Further braking is performed until it hangs with a decrease in the reactive thrust of the combined engine 14 and with a corresponding increase in the power supply to the coaxial rotor. The flaps 17 and the deflectable wing consoles 22 deviate downward by 90 degrees. Landing is carried out by helicopter - vertically on the released chassis 20.

The set of distinctive features of the proposed utility model provides a solution to the technical problem:

- the use of the concept of zero thrust (ZT) introduced by us on a high-speed combined helicopter (rotorcraft) by sharing the rotor, wing, PGO and combined engine. At the same time, in flight modes with speeds of more than 400 km / h, the wing provides both almost complete unloading of the rotors and a significant decrease in the amplitude of the flywheel movement of the blades when flying at a low speed, which reduces the resistance of the rotors, the load in the structural elements and virtually eliminates the influence of the rotors on the energy of the rotorcraft, its controllability and balancing, as well as the possibility of maneuvering with large overloads, while maintaining low thrust of the rotors by increasing the lifting force of the wing beyond through the use of mechanization.

- the use of front horizontal controlled plumage (PGO) to balance the high-speed combined helicopter (rotorcraft) with positive lift. PGO increases the aerodynamic quality of the airframe (in classic, adopted on modern helicopters aerodynamic layouts, the plumage, as a rule, has a negative lift);

- the use of the wing to provide the necessary bearing capacity, which, in combination with the use of PGO, provides high aerodynamic quality;

- the use of a high degree of wing mechanization with flaps and elevons, providing improved controllability and the possibility of a significant increase in vertical overload when flaps are deflected to increase the wing lift so that the rotor lifting coefficient and its rotational speed practically do not increase with a general increase in the angle of attack rotorcraft;

- the selection of the rotor speed is carried out in such a way as to ensure the maximum allowable Mach number in the end sections of the advancing blades, permissible loads in the structural elements and optimal power consumption.

Thus, the proposed technical solution for a high-speed combined helicopter (rotorcraft) eliminates the gap in the class of promising high-speed means of vertical take-off and landing, significantly expands the possibilities for increasing the helicopter's flight speed, and significantly improves its flight technical and maneuverability, which will contribute to its competitiveness.

The inventive combined helicopter can be manufactured in mass production using existing materials and technologies in the industry.

Claims (1)

High-speed combined helicopter - rotorcraft having a combined load-bearing system, consisting of a coaxial rotor and a glider with horizontal and vertical tail with controllable surfaces, a power plant, consisting of a transmission (gears and shafts) and an engine, retractable in flight landing gear, characterized in that equipped with a wing located behind the axis of the shaft of the coaxial rotor, equipped with controlled flaps, elevons and deflectable consoles and at least one engine made combined m and providing both the creation of propulsive jet thrust by means of a tail nozzle in all operational flight modes, and a drive with the ability to change the rotational speed of the coaxial rotor, while the horizontal controlled tail is located in front of the axis of the coaxial rotor shaft, and the vertical tail is mounted on the wing.

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