RU2463216C1 - Method for protection of fire-fighting amphibian airplane power plant against foreign objects entering and vortices destruction at air intake of dual-flow turbojet engine (dftje) - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft, in particular, to methods of operation and protection of dual-flow turbojet engines of fire-fighting amphibian airplanes against foreign objects entering. Protection method consists in blowing out high-pressure streams in front of dual-flow turbojet engine air intake. Blowing out is performed by water taken from water tanks of fire-fighting amphibian airplane and creates dynamic water curtain aimed forward and down from lower air intake half-ring and in emergencies - additionally from engine spinner along periphery towards fan contour.

EFFECT: higher efficiency of amphibian airplane dual-flow turbojet engines protection.

3 dwg

Description

The invention relates to the field of aviation, and in particular to the operation of fire-fighting amphibious aircraft on which turbofan engines (turbofan engines) are installed.

The need to protect the power plant is caused by the fact that during take-off, in flight, during landing approach in the air intakes of the turbofan engine of fire-fighting amphibious aircraft, foreign objects, birds can get. Especially dangerous in recent years have been the cases of birds getting into the air intakes of turbofan engines of fire-fighting amphibian aircraft during operations to extinguish forest fires.

A device for protection containing a rotor is installed in the inlet channel between the air intake and the engine. The rotor rotates in the opposite direction of the main rotation of the engine. In this case, a backpressure is created in the input channel. As a result, particles entering the inlet channel are thrown upstream and enter the collector (1) through the openings.

The disadvantage of this device is a significant complication of the design of the engine, insufficient protection against the ingress of birds.

Also known are methods and devices that supply compressed air jets to the surface of the runway before entering the engine air intake (2), (3).

The disadvantages of these methods are significant loss of engine thrust during take-off due to additional air withdrawals from high-pressure engine compressors (HPC).

There is a method of destroying the vortices at the inlet of the turbojet air intake and a device for its implementation (4), which also provide for significant power takeoffs from the aircraft engine.

The closest in technical essence and adopted as a prototype is a method of protecting the engine air intake from foreign particles (5), in which a continuous conical stream of air is formed along the engine axis in the direction of the air intake.

The disadvantage of the prototype considered is the use of large air volumes from the HPC compressor to protect the engine from foreign objects and poor efficiency when large birds weigh up to 4.5 kg (this weight is regulated by modern certification standards).

The objective of the proposed method is to create effective protection during the operation of turbofan engines on amphibious aircraft, increase the life of the engine, increase the take-off thrust of the engine due to the complete exclusion of air intake from the high-pressure compressor.

The proposed method of protecting the air intake of a turbofan engine of a fire-fighting amphibious aircraft consists in blowing high-pressure water jets through the nozzles of a centrifugal type in front of the air inlet forward and downward, and in an emergency, when a bird enters the flock, additional blowing of water from the openings on the engine coke is activated through the nozzles centrifugal type, on the periphery towards the fan circuit of the turbofan engine.

The masses of air that are sucked into the engine’s air intake pick up foreign objects raised from the surface of the water or the ground during take-off of the fire amphibious aircraft, including birds flying by, and direct them into the gas-air path of the turbofan engine.

Particularly dangerous for an aircraft engine is the ingress of foreign objects into the internal circuit of the engine - a gas generator, where the blades of compressors, turbines, nozzles are destroyed, which leads to premature engine failure and costly repairs, and often leads to an airplane crash.

It is also necessary to note a frequently occurring dangerous phenomenon - air vortices at the inlet of the turbojet air intake, leading to dangerous stall phenomena - loss of stability of the aircraft engine in a given mode, which leads to the appearance of engine surging.

The proposed method is aimed at eliminating these shortcomings and allows you to completely eliminate the air intake from the aircraft engine in all flight modes.

Compared with the prototype and other identified technical solutions, the proposed method has novelty, inventive step and industrial applicability.

Figure 1 presents a diagram of the turbojet air intake and a device that implements protection against the ingress of foreign objects and air vortices.

Figure 2 presents a General view of the engine module propulsion turbofan engine fire amphibious aircraft (side view).

Figure 3 shows the take-off of a fire amphibious aircraft from a water surface and the operation of the system.

A device for implementing the proposed method comprises an air intake housing 1 with a manifold 2, on which centrifugal nozzles 3, a motor coke 4 with centrifugal nozzles 5, a piping system 6, a high pressure water pump 7 mounted on a turbofan drive box 8, water tanks 9 are installed, the control valve for supplying water 10 to the manifold 2 located in the nose of the air intake, the control valve for supplying water 11 to the manifold 12 located in the engine coke 4, radar 13 installed in the nose of the fire-fighting aircraft - mfibii, the operation control unit 14 of the device.

The essence of the method is as follows.

When a fire amphibious aircraft takes off from land or water, the control unit for the operation of the turbofan engine 14 located in the nose of the aircraft is turned on.

Water through the piping system from the main tank 9 of the amphibian fire-fighting aircraft through a high-pressure pump 7 mounted on the drive box 8, enters through the manifold 2 into centrifugal nozzles 3 located in the air intake half-ring and is thrown forward and down in the form of a continuous water curtain to the air intake of an aircraft engine.

After climbing the aircraft, the protection system is disabled. The second part of the device operates, as a rule, in standby mode. According to the signal from the radar 13 installed behind the fairing in the nose of the aircraft, when birds appear in front of the amphibian aircraft at a distance of up to 100 meters, the signal enters the control unit 14, an additional system of centrifugal nozzles 5 installed in the engine coke 4 is turned on.

The water curtain inside the air intake creates additional centrifugal force to all foreign objects that have fallen into the air intake, dropping them into the flowing part of the fan circuit area of the engine.

In the absence of a signal about the presence of foreign objects (birds), the control system 14 is automatically turned off, and water does not enter the engine coke 4, centrifugal nozzles 5. It is possible to manually control the pilot of this system using the toggle switch installed on the central console.

This method also allows you to successfully deal with air vortices arising at the entrance to the turbojet air intakes.

The use of water having a density of 1000 times more than air to protect against the ingress of foreign objects and birds into the air intakes of turbofan engines for fire amphibious aircraft is due to the fact that these aircraft have on board large water reserves stored in water tanks (tank capacity Be-200ES aircraft up to 12 tons of water).

Currently, the complex is working on preliminary layout of the device on a Be-200ES aircraft.

Information sources

1. A device for protecting the power plant of an aircraft from foreign objects. A.S. No. 865694, IPC B64D 33/02, F02C 7/04.

2. A method of protecting the air intake of turbojet engines of an aircraft powerplant against foreign objects V.M.Vul, No. 4924034/23.

3. A method that prevents vortex formation, and a device for jet engines of the aircraft. US patent 3599429, IPC B64C 7/04, B64D 33/02, NCI 60 / 39.09P, 244/53 V.

4. The method of destruction of the vortices at the entrance to the GTE air intake and a device for its implementation. Patent No. 2046066, IPC ⁶ B64D 33/02, B64C 25/00.

5. A method of protecting the gas intake of a gas turbine engine from the ingress of foreign particles. Patent No. 2156369, IPC ⁷ F02C 7/05.

Claims (1)

A method for protecting a power plant of a fire-fighting amphibious aircraft from foreign objects and destroying vortices at the inlet of the air intake of a dual-circuit turbojet engine, which consists in blowing high-pressure jets in front of the air intake, characterized in that blowing is carried out with water taken from the water tanks of the fire-fighting amphibian, creating dynamic water curtain in the direction from the lower half-ring of the air intake downward, and urgently - from the engine coke on the periphery to the side Onu fan circuit.

Images