RU2749234C1 - Aircraft turbojet engine - Google Patents

Abstract

FIELD: aviation.SUBSTANCE: invention relates to aircraft turbojet engines. The proposed aircraft turbojet engine contains an air intake 1, in a cylindrical body 2 along the axis of which a shaft 3 is installed, which is connected in series with a multistage compressor 4 and a turbine 6, as well as a pressurization unit, a combustion chamber 5, a kinematic connection with a start drive 9 and an outlet device 7. The pressurization unit is made autonomous, installed in the air intake 1 along the axis of the housing 2 by means of three radial brackets 10 through the gap in front of the compressor 4 and is not connected to the shaft 3, the pressurization unit consists of single assembly: an electric motor 11, a gearbox and a two-blade propeller 12. The electric motor 11 is connected to the onboard electrical network through the body 16 of the autonomous manual step control, combined with the body 18 of the aircraft turbojet engine control. The space between the plane of rotation of the propeller 12, the wall of the cylindrical body 2 and the plane of the first stage of the compressor 4 is a receiver 14, and a pressure gauge 15 is connected to the inner space of the receiver 14.EFFECT: invention makes it possible to increase the compression ratio of the compressor and improve the characteristics of the turbojet engine.1 cl, 3 dwg

Description

The invention relates to aeronautical engineering, more specifically to an aircraft turbojet engine with an axial compressor.

Known aircraft turbojet engine, see for example, Encyclopedia of Aviation, ed. TSAGI TSAGI, 1994, article NK, pp. 379-380, containing an air intake in a cylindrical housing along the axis of which a shaft is installed, connected in series with a pressurization unit made by a multi-blade radial-axial fan, a multistage compressor and a turbine, as well as a combustion chamber, a kinematic communication with the starter drive and output device.

The principal theoretical disadvantages of an aircraft turbojet engine (traditional) are as follows.

a) PASSIVE air consumption through the cross-section of the air intake, i.e. the engine cannot receive a mass quantity of air greater than that which passes through the cross-section of the air intake. Hence, it becomes necessary to increase the external dimensions of the engine, the diameter of its air intake. This disadvantage can be overcome: either by increasing the cross-section of the engine - its diameter (the most important characteristic of the engine is the "fan diameter" and, accordingly, the engine diameter), or by increasing the compression of the passive air entering through the air intake by additional compressor stages (engine characteristic - the bypass ratio), increasing the axial the length and complexity of the engine, or the use of more complex engine design schemes: double-circuit, three-stage, with a fan reducer, etc., which significantly complicates it.

b) Another fundamental theoretical strategic disadvantage of an aircraft turbojet engine is one-component engine control. The fact is that two components are involved in the operation of a turbojet engine, namely: air and fuel. Engine control - the creation and change of thrust is carried out by only one component - fuel by changing the amount and time of its supply to the engine

The principle of operation, design, theoretical justification of the traditional aircraft turbojet engine EXCLUDE independent ACTIVE engine control by means of another component - air.

The principle of operation of a traditional turbojet engine is being revised, namely: the amount of thrust of the engine should be provided mainly not by a high fuel consumption, but by an excess consumption of free outboard air.

c) Starting a turbojet aircraft traditional engine (prototype) is carried out by scrolling the rotor shaft through a kinematic link driven by a starter-generator with excessive fuel supply, which can lead to a critical increase in the temperature of gases in the turbine, possibly damaging it and reducing the service life. This electromechanical method of starting the engine is a disadvantage of the traditional turbojet engine, because it becomes possible to apply a more efficient pneumatic starting method.

The purpose of the invention is the elimination of the listed disadvantages. Improving the fundamental quality characteristics of a turbojet engine.

This goal is achieved by the fact that the aircraft turbojet engine contains an air intake, in a cylindrical housing along the axis of which there is a shaft connected in series with a multistage compressor and a turbine, as well as a pressurization unit, combustion chambers, a kinematic connection with the launch drive and an output device. The pressurization unit is made autonomous, installed in the air intake along the axis of the housing by means of three radial brackets through the gap in front of the compressor and is not connected to the shaft, consists of a single assembly: an electric motor, a gearbox and a two-blade propeller. The electric motor is connected to the on-board electrical network through an autonomous manual step control, combined with an aircraft turbojet engine control. The space between the plane of rotation of the propeller, the wall of the cylindrical body and the plane of the first stage of the compressor is a receiver, and a pressure gauge is connected to the inner space of the receiver.

The novelty of the development lies in the fact that the operation of an aircraft turbojet engine (creating and changing thrust) differs significantly from the operation of a traditional aircraft turbojet engine (prototype) in that the engine is controlled by two components, namely: separate autonomous air and fuel supply. Moreover, the air supply is carried out in a much larger mass volume and it is possible to regulate the time and quantity of its supply. In the jet stream of the outlet apparatus of a turbojet engine, the larger part is occupied by the air supplied in excess by the propeller and compressed by the compressor, than the flow of the burning mixture of fuel with air, which achieves a lower fuel consumption.

In a traditional aviation turbojet engine, a fan is excluded, but an autonomous controlled pressurization unit - a propeller, is additionally introduced, the air thrust of which is an air flow used for forced air supply and, in a larger quantity, a turbojet engine compressor.

The design of an aircraft turbojet engine is shown:

fig. 1 diagram of an aircraft turbojet engine with an axial compressor with an autonomous pressurization unit in the air intake, section along the longitudinal vertical plane.

fig. 2 aircraft turbojet engine with an axial compressor with a pressurization unit in the air intake and attachment to the inner surface of the engine body, front view against the direction of flight.

fig. 3 combined stick to control the engine on an airplane throttle.

List of positions

1 air intake,

2 motor housing,

3 shaft,

4 compressor,

5 combustion chamber,

6 turbine,

7 output device,

8.kinematic connection,

9 start drive,

10 bracket,

11 electric motor,

12 propeller,

13 fairing,

14 receiver,

15 pressure gauge,

16 handle "pressurization",

17 cable to the actuator,

18 handle throttle,

19 spring.

Symbols applied.

NP - direction of flight,

CR - emergency mode (no more than 2 minutes),

APU - auxiliary power unit,

RUD - engine control handle,

RD - taxiway.

An aircraft turbojet engine (see Fig. 1) consists of an air intake 1, a cylindrical body 2, a shaft 3 with a compressor 4 installed in series on it and a turbine 6 behind the combustion chamber 5, an outlet 7, shaft 3 has a kinematic connection 8 with drive 9 start. In the vertical section of the air intake 1, a pressurization unit is installed on three radial brackets 10 (see Fig. 1 and Fig. 2), the brackets 10 are tear-shaped in cross-section, with a tip forward along the NP to reduce (eliminate) the build-up of ice during icing. The pressurization unit consists of a single assembly: an electric motor 11, a planetary gearbox and a two-blade propeller 12 with a radial clearance of 6-10 mm less than the inner diameter of the air intake 1, equipped with a fairing 13, which is not subject to icing, because the electric motor generates heat during continuous operation. A compound DC electric motor with an approximate power of about 50-70 kW was used. continuous action, its serial winding allows to provide the PD mode, and the shunt one in steady flight. For propeller 12, operating under specific conditions of a turbojet engine, an experimental selection of characteristics is required: its chord, angle of attack, longitudinal twist (pitch). The closed free space between the plane of rotation of the propeller 12, the wall of the cylindrical body 2 and the plane of the first stage of the compressor is the receiver 14. A pressure gauge 15 is connected to the interior of the receiver 14, installed in the aircraft cabin. The electric motor 11 of the pressurization unit is connected to the on-board electrical network through an autonomous manual step-by-step control lever 16 "pressurization" with a cable 17 to the actuator (see Fig. 3), Stick 16 "pressurization" is combined with the control unit 18 of the turbojet engine throttle on the aircraft so , which allows one hand to simultaneously control both the throttle and the "boost", i.e. supplying air and fuel to the engine. The handle 16 "pressurization" can be made with step adjustment (for example 3-4 fixed positions) or with smooth adjustment. The extreme position "up to the stop" is equipped with a counter spring 19 and corresponds to the PD position of the engine operation.

Work. In the closed annular space of the receiver 14, the pressurization unit by means of the “pressurization” handle 16 creates air pressure, which is controlled by the pilot. The air pressure corresponding to a significantly greater mass quantity of air than in the atmosphere surrounding the aircraft is directly perceived by the first stage of compressor 4, increasing the compressor compression ratio, thus improving all characteristics of the turbojet engine. The optimal operating mode of the pair: "propeller - compressor" is established when the pressure created in the receiver is constant and completely absorbed by the compressor, which is controlled by the constant reading of the pressure gauge 15 and the constant value of the electric current of the electric motor 11.

EFFECT: changes in the method of starting a turbojet engine on an aircraft. It is possible to abandon the mechanical unwinding of the shaft 3 by means of the kinematic connection 8 by the launch drive 9 from the APU, the on-board battery or a ground source of electrical energy. The engine is started by pneumatic spinning of shaft 3 through compressor 4 by a pressurization unit. Upon reaching certain revolutions of shaft 3, the pilot sets with the throttle handle the flow of fuel and ignition into the engine, controlling the engine output to the desired mode. In the modes "starting off", "starting from the ground on taxiways", "starting off from an ice crust or from a snowdrift", etc., if necessary, the pilot squeezes the handle 16 "pressurization" until the compression of the spring 19, the CR mode for a short time, in this case, the turbine will not experience critical temperatures, because more air will flow into the outlet 7.

What is especially important is that forced pressurization will ensure the efficiency of using a traditional aviation turbojet engine up to the stratosphere up to heights of 10.600 m and more up to 12.400 m, which practically does not limit the operation of long-haul aircraft in altitude.

The technical and economic effect of the invention is that it opens up the possibility of creating a new class of aircraft turbojet engines with many improved characteristics, which directly improve the quality characteristics of the aircraft.

Claims (1)

An aircraft turbojet engine containing an air intake, in a cylindrical housing along the axis of which there is a shaft connected in series with a multistage compressor and a turbine, as well as a pressurization unit, combustion chambers, a kinematic connection with a starting drive and an output device, characterized in that the pressurization unit is made autonomous, installed in the air intake along the axis of the housing by means of three radial brackets through the gap in front of the compressor and is not connected to the shaft, consists of a single assembly: an electric motor, a gearbox and a two-blade propeller, while the electric motor is connected to the on-board electrical network through an autonomous manual step control, combined with the body control of an aircraft turbojet engine, while the space between the plane of rotation of the propeller, the wall of the cylindrical body and the plane of the first stage of the compressor is a receiver, and a pressure gauge is connected to the inner space of the receiver.

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