RU2701083C1 - Helicopter - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to aircraft engineering, particularly, to helicopters. Helicopter comprises fuselage with bottom and tail, two coaxial screws on concentrically arranged shafts connected via reduction gear with gas turbine engine, having air intake, compressor, combustion chamber, turbine and nozzle. Gas-turbine engine is made birotatory, containing birotatory compressor and birotatory turbine and installed vertically in helicopter center of mass inside streamlined axisymmetric casing with formation of external circuit with external air intake and external nozzle. On the fuselage bottom the safety platform is made, which has vertical holes for arrangement of the gas turbine engine nozzle. Inner cavity of safety platform is filled with damping material. Damping material can be a honeycomb structure or metal rubber.

EFFECT: safe landing at destruction of propeller.

10 cl, 12 dwg

Description

The invention relates to aviation, and more specifically to helicopters with gas turbine engines and is aimed at improving the safety of their flight.

A helicopter is a rotary-wing aircraft in which the lifting and driving forces are generated by one or more rotors. Such screws are parallel to the ground, and their blades are installed at a certain angle to the plane of rotation, and the installation angle can vary over a fairly wide range - from zero to 30 degrees. Setting the blades to zero degrees is called idle screw or feathering. In this case, the rotor does not generate lift.

During rotation, the blades capture air and discard it in the opposite direction to the movement of the screw. As a result, a zone of low pressure is created in front of the screw, and behind it a high pressure. In the case of a helicopter, a lift arises this way, which is very similar to the formation of lift by a fixed wing of an airplane. The larger the angle of the blades, the greater the lifting force creates a rotor.

The characteristics of the rotor are determined by two main parameters - diameter and pitch. The diameter of the propeller determines the helicopter's take-off and landing capabilities, as well as partly the magnitude of the lifting force. The pitch of the screw is the imaginary distance that the propeller travels in an incompressible medium at a certain angle of installation of the blades in one revolution. The last parameter affects the lifting force and rotor speed, which the pilots try to keep unchanged for most of the flight, changing only the angle of the blades.

A helicopter is a rotary-wing aircraft in which the lifting and driving forces are generated by one or more rotors. Such screws are parallel to the ground, and their blades are installed at a certain angle to the plane of rotation, and the installation angle can vary over a fairly wide range - from zero to 30 degrees. Setting the blades to zero degrees is called idle screw or feathering. In this case, the rotor does not generate lift.

During rotation, the blades capture air and discard it in the opposite direction to the movement of the screw. As a result, a zone of low pressure is created in front of the screw, and behind it a high pressure. In the case of a helicopter, a lift arises this way, which is very similar to the formation of lift by a fixed wing of an airplane. The larger the angle of the blades, the greater the lifting force creates a rotor.

The characteristics of the rotor are determined by two main parameters - diameter and pitch. The diameter of the propeller determines the helicopter's take-off and landing capabilities, as well as partly the magnitude of the lifting force. The pitch of the screw is the imaginary distance that the propeller travels in an incompressible medium at a certain angle of installation of the blades in one revolution. The last parameter affects the lifting force and rotor speed, which the pilots try to keep unchanged for most of the flight, changing only the angle of the blades.

When the helicopter is flying forward and the rotor is rotated clockwise, the incoming air flow has a stronger effect on the blades on the left side, which increases their efficiency. As a result, the left half of the circle of rotation of the screw creates a greater lifting force than the right, and there is a heeling moment. To compensate, the designers came up with a swashplate - this is a special system that reduces the angle of installation of the blades on the left and increases it on the right, thus leveling the lifting force on both sides of the screw.

In general, a helicopter has several advantages and several disadvantages over an aircraft. The advantages include the possibility of vertical take-off and landing on sites whose diameter is one and a half times greater than the diameter of the rotor. In this case, the helicopter can carry bulky loads on the external sling. Helicopters are also distinguished by better maneuverability, since they can hang vertically, fly sideways or backwards, and rotate in place.

The disadvantages include greater fuel consumption than aircraft, greater infrared visibility due to hot exhaust from the engine or engines, as well as increased noise. In addition, a helicopter as a whole is more difficult to control due to a number of features. For example, helicopter pilots are familiar with the phenomena of earth resonance, flutter, a vortex ring, and the effect of locking a rotor. These factors can cause the machine to crash or crash.

In helicopter technology of any circuit there is a mode of autorotation. It refers to emergency modes. This means that if, for example, the engine fails, the main rotor or screws are disconnected from the transmission by means of an overrunning clutch and begin to spin freely with an oncoming air stream, slowing down the machine’s fall from a height. In autorotation mode, a controlled emergency landing of the helicopter is possible, and a rotating rotor through the gearbox continues to spin the steering screw and generator.

Classic design

Of all the types of helicopter circuits today, the most common is the classic. With this arrangement, the machine has only one rotor, which can be driven by one, two, or even three engines. This type, for example, includes the shock drums AN-64E Guardian, AH-1Z Viper, Mi-28N, transport-combat Mi-24 and Mi-35, transport Mi-26, multi-purpose UH-60L Black Hawk and Mi-17, light Bell 407 and Robinson R22.

When the rotor rotates on helicopters of the classical scheme, a reactive moment arises, due to which the machine body begins to unwind in the direction of rotation of the rotor. To compensate for the moment using the steering device on the tail boom. As a rule, it is a tail rotor, but it can also be a fenestron (a screw in an annular cowl) or several air nozzles on the tail boom.

The second scheme of the helicopter

The second most common helicopter scheme is coaxial. There is no steering screw in it, but there are two main rotors - the upper and lower. They are located on one axis and rotate synchronously in opposite directions. Thanks to this solution, the screws compensate for the reactive moment, and the machine itself turns out to be somewhat more stable compared to the classical scheme. In addition, coaxial helicopters have virtually no cross-linking in control channels.

The most famous coaxial helicopter manufacturer is the Russian company Kamov. It produces Ka-27 multi-purpose ship helicopters, Ka-52 attack helicopters and Ka-226 transport helicopters. All of them have two screws located on the same axis one below the other. The machines of the coaxial scheme, in contrast to the helicopters of the classical scheme, are able, for example, to make a funnel, that is, to fly around a target in a circle, remaining at the same distance from it. In this case, the nose always remains deployed towards the target. Yaw control is carried out by braking one of the rotors.

In general, controlling coaxial helicopters is somewhat easier than conventional helicopters, especially in hover mode. But there are also their own characteristics. For example, when performing a loop in flight, overlapping of the lower and upper rotor blades may occur. In addition, in design and manufacturing, the coaxial design is more complex and expensive than the classic design. In particular, because of the gearbox that transfers the rotation of the motor shaft to the screws, as well as the swash plate, which simultaneously sets the angle of the blades on the screws.

Known safe helicopter according to the patent of the Russian Federation for the invention No. 2333135, IPC ВСС 27/04, publ. September 10, 2008

This helicopter contains a traction engine and a rotor with a vertical axis, on top of which there is an even number, but not less than four blades. The helicopter also contains a connecting device that plays the role of a transmission in the operating mode of the traction engine, and in the operating mode of the starting engines - the role of the overrunning clutch mechanism. Each second rotor blade has a calculated shortened dimension of overall length and includes in its device one or more elementary starting engines, for example, operating on solid fuel. The invention improves safety during emergency landing of a helicopter.

Disadvantage: low reliability.

Known helicopter according to the patent of the Russian Federation for the invention No. 2335432, IPC ВСС 27/04, publ. 10/10/2008

This helicopter includes a fuselage and coaxial screws, and the screws can be two or more and they can be of different diameters. At least one of the screws is controlled with a variable pitch, and the rest with a fixed pitch. In the second embodiment, the helicopter has a tail boom with an elastic pneumatic chamber at the end, and when the beam is raised, thrust reduction is blocked. In the third embodiment, the engine and gearbox are placed in a separate engine nacelle located above the fuselage on the pylons and / or elastic inserts.

Disadvantage: low reliability of the helicopter due to the fact that when one propeller breaks, the thrust of the other is not enough for it to land and, in addition, the occurrence of an imbalance disrupts the operation of the second propeller.

Known helicopter according to the patent of the Russian Federation No. 2 284284, IPC B64D 45/04, publ. 08/27/2006.

This helicopter has a safe landing system for a helicopter falling during an air accident. The safe landing system includes a parachute located in a hollow cylinder located in the cavity of the transmission shaft on which the rotor is mounted, as well as jet braking engines and inflatable devices located in the lower part of the helicopter fuselage. The specified hollow shaft is made in the form of a steel pipe and has gear wheels of the drive, made on it as one unit.

Disadvantages:

- the use of parachutes to rescue helicopters with a very large weight is unrealistic,

- the use of inflatable means is also unrealistic for large helicopters and in addition they are fire hazardous,

- the use of jet engines is promising, but the type of jet engine and the method of its use are not indicated.

- the use of solid rocket engines is unrealistic due to their fire and explosion hazard,

- the use of liquid rocket engines is problematic due to the need for constant transportation of the oxidizing agent.

The use of gas turbine engines is possible, but it is necessary to develop its design, installation location and method of application. This is not in US Pat. RF №2 284284. In addition, this patent assumes the combined use of parachutes and jet engines (several), which reduces the reliability of the helicopter.

Known helicopter according to the patent of the Russian Federation for the invention No. 2148537. IPC V64C 7/20, publ. 05/10/2002, the prototype.

This helicopter contains a housing, an air-jet engine for generating thrust for horizontal flight, rotors that are located inside the housing and serve as a compressor for an air-jet engine, an engine that is designed to rotate these rotors, and the cockpit. A protective net is provided under which the rotors are located. Sashes are located below the net and are designed for take-off and landing.

Disadvantage: poor flight safety due to this. that when the propeller is destroyed, landing a helicopter will almost always lead to disastrous consequences.

Objectives of the invention: improving the reliability and safety of flight, simplifying control and reducing the axial dimensions of the engine.

Effect: ensuring a safe landing when the screw is destroyed.

The solution of these problems was achieved in a helicopter containing a fuselage with a bottom and a tail, two coaxial screws on concentrically arranged shafts connected through a gearbox to a gas turbine engine having an air intake, compressor, combustion chamber, turbine and nozzle, in that the gas turbine engine is made biotic, containing a biotic compressor and a biotic turbine and is installed inside a streamlined axisymmetric casing with the formation of an external circuit with an external air intake and an external nozzle, while a gas turbine second motor is mounted vertically in the center of mass of the fuselage, the fuselage at the bottom of the formed security platform having a vertical hole to accommodate a nozzle of a gas turbine engine, a damping material is filled inside the cavity of the security framework.

An afterburner may be formed between the turbine and the nozzle of the gas turbine engine.

The gas turbine engine may be a power take-off shaft connected to auxiliary units.

As the damping material, a honeycomb structure may be used.

As a damping material, metal rubber may be used.

At the end of the tail, a propulsive propulsion device in the form of a pushing screw can be installed. The fuselage can be equipped with front wings on which marching engines are installed.

Marching engines can be made in the form of turboprop gas turbine engines.

Marching engines can be made in the form of turbojet gas turbine engines.

The invention is illustrated in the drawings (Fig. 1 ... 12). Where:

- in FIG. 1 shows a diagram of a helicopter,

- in FIG. 2 is a view A of FIG. one.

- in FIG. 3 shows the layout of the screw, gearbox and gas turbine engine,

- in FIG. 4 shows a gas turbine engine of a helicopter, the first option in operating position.

- in FIG. 5 shows a gas turbine engine, a helicopter, the second option in working position.

- in FIG. 6 shows the design of a gas turbine engine of a helicopter; the first option is rotated 90 °.

- in FIG. 7 shows the design of a gas turbine engine of a helicopter, the 2nd option is rotated 90 °.

- in FIG. 8 shows a diagram of the transfer of power from the turbine engine to the screws,

- in FIG. 9 shows a variant of a helicopter with a marching propulsion on the tail,

- in FIG. 10 shows a variant of a helicopter with a marching engine on the front wings.

- in FIG. 11 shows the security platform,

- in FIG. 12 shows a section B - B.

A safe helicopter (Fig. 1 and 2) contains the fuselage 1, coaxial screws: upper 2 and lower 3, coaxial shafts 4 and 5, connecting screws 2 and 3 through a reducer 6 with two power take-off shafts 7 and 8 from a gas turbine engine 9 installed vertically in the region of the center of mass of the helicopter (Fig. 1 and 2).

The gas turbine engine 9 has a power take-off shaft 10 for driving auxiliary units (Fig. 3).

A safety platform 12 is fixed on the bottom 11 of the fuselage 1, the cavity 13 of which is filled with a damping material 14. As a damping material 14, a honeycomb filler or metal rubber can be used. In the safety platform 12, a central hole 15 is made 15. Landing legs 16 are attached to the bottom 11.

The gas turbine engine 9 (GTE) contains (Fig. 3) an air intake 17, a compressor 18, a combustion chamber 19 with nozzles 20, a turbine 21, and a nozzle 22.

The gas turbine engine 9 according to the first embodiment (Fig. 3) has one main fuel system 23. The main fuel system 23 comprises a fuel pipe 24 in which a fuel pump 25 is connected to the drive 26.

The gas turbine engine 9 is made of birotational and contains two shafts: inner 27 and outer 28, connected through a coupling 29 to the power take-off shafts 7 and 8. The inner and outer shafts 27 and 28 rotate in opposite directions. This eliminates the reactive moment, turning the fuselage 1 in the opposite direction and simplify control of the helicopter.

In FIG. 5 shows a second embodiment of a gas turbine engine 9, which further comprises an afterburner 30 with an afterburner manifold 31 (with nozzles) inside and an afterburner fuel system 32.

The afterburner fuel system 32 comprises a fuel line 33 with an afterburner pump 34 installed therein, to which a drive 35 is connected. The fuel line 33 is connected to the afterburner manifold 31.

The gas turbine engine 9 is mounted vertically in the center of mass of the fuselage 1 of the helicopter (Fig. 1).

The safety platform 12, as mentioned earlier, has a central hole 15 made vertically on an axis passing through the center of mass of the helicopter and a gas turbine engine 9. The diameter of the central hole 15 D _{0 is} larger than the cut-off diameter of the outer nozzle 49 - D _c .

D ₀ ≥D _c .

In FIG. 6 shows in more detail the design of the gas turbine engine 9 of the helicopter, the first option is rotated 90 °.

The gas turbine engine 9, as mentioned earlier, comprises an internal shaft 27 mounted on the internal bearings 36, a compressor stator 37, two compressor rotors 38 and 39 configured to rotate in the opposite direction and without guide vanes between them, a turbine stator 40, and two rotors turbines 41 and 42, also made to rotate in opposite directions and without nozzle devices between them. An external gearbox 43 is connected to the external shaft 28, to which a power take-off shaft and a power take-off shaft 44 are connected for power take-off to auxiliary units, for example, an electric generator. The first rotor of the compressor 38 and the second rotor of the turbine 42 are connected by an internal shaft 27.

The second rotor of the compressor 39 and the first rotor of the turbine 41 are connected by an external shaft 28 mounted on the external bearings 45.

The use of a biotic scheme of a gas turbine engine 9 will reduce its axial dimension, weight and eliminate the reactive moment acting on the fuselage. In addition, the gyroscopic effects from two rotors rotating in the opposite direction are mutually compensated. This will greatly simplify the management of the helicopter.

In FIG. 7 shows the design of the gas turbine engine 9 of the helicopter, the 2nd option, with afterburner rotated 90 °.

In addition to the first embodiment, between the turbine 21 and the nozzle 22 there is an afterburner 29 with an afterburner 30 for fuel injection in afterburner modes.

The afterburner fuel system 32 comprises a fuel line 33 with an afterburner pump 34 installed therein, to which a drive 35 is connected. The fuel line 33 is connected to the afterburner manifold 31.

In FIG. 8 shows a diagram of the power transmission from the turbine engine 9 to the screws 2 and 3 through the gearbox 6. From the shafts 10 of the main turbine engine 8 to the shaft 5, a coupling 29 is installed between them.

A gas turbine engine 9 is installed inside a streamlined axisymmetric casing 46 with the formation of an external circuit 47 with an external air intake 48 and an external nozzle 49 (Figs. 1, 2, and 8).

In FIG. 9 shows a variant of a helicopter with a propulsion engine 50 on the tail 51.

Marching propulsion 50 can be made in the form of a pushing screw 52. The drive of the pushing screw 52 is carried out from the gearbox 6 through the shaft 53 and the clutch 54. The helicopter can have rear wings 55.

In FIG. 11 shows a variant of a helicopter with a mid-flight engine 56 on the front wings 55. The mid-flight engines 56 can be made in the form of a turboprop engine or in the form of a gas turbine engine.

In FIG. 12 shows a security platform 12, and FIG. 10 shows a section BB. A nozzle 22 is installed inside the outer nozzle 49.

HELICOPTER OPERATION IN NORMAL MODE, 1 option

First start the gas turbine engine 9 in the "small gas" mode (Fig. 1 and 3).

The drive 28 spins the fuel pump 27, the fuel (aviation kerosene) is supplied through the fuel pipe 26 to the nozzles 20 of the combustion chamber 19, The combustion products pass through the turbine 21. The power from the turbine 21 is transmitted to the compressor 18, which compresses the air coming through the air intake 17. Compressed air fed to the combustion chamber 19 to maintain the combustion process,

The jet thrust of the gas turbine engine 9 created by the nozzle 22 and the external nozzle 55 is transmitted to the fuselage 1, which, in combination with the thrust force of the screws 2 and 3, ensures takeoff, flight of the helicopter and its landing in normal mode.

Cold air flowing from the nozzle of the external 55, mixing with combustion products flowing from the nozzle 22 reduces the temperature of the jet stream and thereby increases the safety of take-off and landing.

After warming up the gas turbine engine, the main fuel system 23 is switched to “take-off mode”. The helicopter takes off vertically.

Joint traction of the screw 2 and the turbine engine 9, taking into account the external circuit 55 in the nominal mode, is 1.05 ... 1.1.

HELICOPTER OPERATION IN EMERGENCY MODE, the first option when breaking one screw

If one screw breaks down, for example, the top 3, disconnect the clutch 29 (Fig. 8) and increase the fuel supply in the main fuel system by 1.5-2 times. Jet thrust created jointly by the upper screw 3 and the nozzle 22 will be enough for a soft landing of the helicopter.

HELICOPTER OPERATION IN EMERGENCY MODE with the second version of the gas turbine engine

If two screws 2 and 3 break down in the embodiment with afterburner 30 (FIG. 4), the afterburner fuel system 31 is activated (FIG. 4). For this, the afterburner drive 34 is launched, which spins the fuel pump 33. Fuel (aviation kerosene) through fuel line 32 it is fed into the afterburner manifold 30 of the afterburner of the combustion chamber 29, where it is ignited by a pilot (not shown), increasing the reactive thrust generated by the nozzle 22. The combustion products through the nozzle 22 flow vertically downward.

The thrust created by the nozzle 22 increases by 2 ... 3 times compared to the afterburner mode, which compensates for the absence of screws 2 and 3 and provides an emergency landing of the helicopter at the cost of a very high fuel consumption.

The use of afterburner 30 in a gas turbine engine 9 allows you to design a gas turbine engine 9 of smaller dimensions and weight, which is very important, since it is extremely rare to use the maximum capabilities of a gas turbine engine 9.

HELICOPTER OPERATION WITH MARCH ENGINE AND MARCH ENGINES

For a variant, a helicopter with marching propulsion 46 on tail 47 (FIG. 11) launches marching propulsion 46 and the helicopter can mix at a sufficiently high speed. The mid-flight mover 46 can be made in the form of a propeller 48. The propeller 48 is driven from the gearbox 6 through the shaft 49 and the coupling 50. The helicopter can have rear wings 51.

For the version of the helicopter with mid-flight engine 52 on the front wings 53 (Fig. 12), mid-flight engines 52 are launched, which creates a horizontal thrust comparable to the thrust of modern high-speed aircraft. In this case, a speed of 700-800 km / h can be achieved, which is necessary for military aircraft.

Marching engines 52 can be made in the form of a turboprop engine or in the form of a gas turbine engine.

The application of the invention allowed:

- to ensure a safe landing when the destruction of one or two screws,

- save the life of the crew and passengers, reduce the axial dimension and weight of the gas turbine engine.

- simplify helicopter control.

- improve the technical characteristics of the helicopter: speed, maneuverability, the height of the helicopter, and other characteristics.

Claims (10)

1. A helicopter containing a fuselage with a bottom and a tail, two coaxial screws on concentrically arranged shafts connected through a gearbox to a gas turbine engine having an air intake, a compressor, a combustion chamber, a turbine and a nozzle, characterized in that the gas turbine engine is made of a rotational one containing a rotational compressor and a biotic turbine and is mounted in the center of mass of the fuselage. 2. The helicopter according to claim 1, characterized in that an afterburner is made between the turbine and the nozzle of the gas turbine engine. 3. The helicopter according to claim 1 or 2, characterized in that the gas turbine engine is connected to auxiliary units by a power take-off shaft. 4. The helicopter according to claim 1 or 2, characterized in that a safety platform is made on the bottom of the fuselage, having vertical openings for accommodating a gas turbine engine nozzle in emergency mode, the internal cavity of the safety platform is filled with damping material. 5. The helicopter according to claim 4, characterized in that the honeycomb structure is used as the damping material. 6. The helicopter according to claim 4, characterized in that metal rubber is used as the damping material. 7. The helicopter according to claim 1 or 2, characterized in that at the end of the tail there is a mid-flight engine in the form of a pushing screw. 8. The helicopter according to claim 1 or 2, characterized in that the fuselage is equipped with front wings on which the main engines are mounted. 9. The helicopter under item 8, characterized in that the mid-flight engines are made in the form of turboprop gas turbine engines. 10. The helicopter under item 8, characterized in that the mid-flight engines are made in the form of turbojet gas turbine engines.

Images