RU2823402C1 - Combined pulsating detonation output device of turbojet bypass gas turbine engine with fuel supply to external circuit - Google Patents

Abstract

FIELD: engine building.

SUBSTANCE: invention can be used for engines with a second circuit without a mixing chamber used in power plants of subsonic aircraft. Technical problem solved by the claimed invention consists in improvement of efficiency. Said problem is solved in bypass turbojet combined pulsating detonation output device with separate external and internal circuits, containing in the internal circuit a converging sound nozzle, and in the outer circuit in the area of the outlet section with a gap between the outer and inner walls of the outer circuit there is a two-dimensional gas-dynamic resonator made in the form of an annular element with a resonator cavity, which traction wall is made in the form of a torus dissected in the cross section, at the same time annular projections are formed on the outer and inner walls of the outer contour, forming an annular gap with the corresponding outer and inner edges of the resonator cavity of the two-dimensional gas-dynamic resonator, besides, it comprises fuel manifold with nozzles to feed additional fuel into flow ahead of its inlet via annular nozzle into two-dimensional gas-dynamic resonator.

EFFECT: higher thrust.

1 cl, 4 dwg

Description

The invention relates to the field of engine building and can be used for engines with a secondary circuit without a mixing chamber used as part of power plants of subsonic aircraft.

From the prior art it is known, developed by the authors of the claimed invention, a combined pulsating output device of a turbojet bypass engine with separate external and internal circuits, containing a tapering sound nozzle in the internal circuit, and in the external circuit in the area of the output section with a gap between the outer and inner walls of the external circuit - a two-dimensional gas-dynamic resonator made in the form of a ring element with a resonator cavity, the traction wall of which is made in the form of a torus dissected in cross section, while on the outer and inner walls of the outer contour annular protrusions are formed, forming an annular gap with the corresponding outer and inner edges of the resonator cavity of the two-dimensional gas-dynamic resonator (RU 2780910 C1, publication date 10/04/2022).

This technical solution increases the thrust and economic characteristics of a turbojet bypass gas turbine engine by 10-15%.

The technical problem solved by the claimed invention is to increase efficiency.

The technical result is to increase the amount of thrust.

The specified technical result is achieved in a combined pulsating detonation output device of a turbojet bypass engine with separate external and internal circuits, containing a tapering sound nozzle in the internal circuit, and a two-dimensional gas-dynamic resonator in the external circuit in the area of the output section with a gap between the outer and inner walls of the outer circuit, made in the form of a ring element with a resonator cavity, the traction wall of which is made in the form of a torus dissected in cross section, while on the outer and inner walls of the outer contour annular protrusions are formed, forming an annular gap with the corresponding outer and inner edges of the resonator cavity of a two-dimensional gas-dynamic resonator, additionally contains a fuel manifold with nozzles installed in the external circuit to supply additional fuel to the flow before it enters through the annular nozzle into a two-dimensional gas-dynamic resonator.

The claimed invention is illustrated in graphic materials, where

Fig. 1 - shows a diagram of a combined pulsating detonation output device with a fuel manifold (1) in the external circuit (4) of the engine (KPDVUf) without mixing flows, where: 1 - fuel manifold; 2- flame stabilizers; 3- spark plug for igniting the air-fuel mixture; 4-external contour; 5-ring two-dimensional gas-dynamic resonator; 6- tapering sound nozzle.

Fig. 2-output device KPDVUf without flow mixing with an external annular nozzle and an annular two-dimensional gas-dynamic resonator (GDR) (5), a sonic convergent nozzle (6) and a fuel manifold in the external circuit (1) (rear view).

Fig. 3- diagram of the installation of a two-dimensional gas-dynamic resonator in an external circuit without mixing flows, where 7 are rings.

Fig. 4 - shock wave reflected from the walls of the resonator at the focus of a flat resonator, where f is the line of foci.

The combined pulsating detonation output device of a turbojet bypass gas turbine engine with fuel supplied to the external circuit (KPDVUf) is an output device of a turbojet bypass gas turbine engine without a mixing chamber with a fuel manifold in the external circuit. The internal circuit uses a traditional tapered sonic nozzle (6). A two-dimensional gas-dynamic resonator (5) is installed in the outer contour of the engine, between its inner and outer walls. The gas-dynamic resonator has the shape of a trench, which is a torus dissected in cross section, installed so that the end of the trench is located at the cut of the outer body of the output device (Figure 1). At the exit from the gas-dynamic resonators, rings are installed (position 7, figure 3), attached to the outer and inner housings of the outer circuit. By changing the distance between the rings and the ends of the resonator, the area of the annular nozzle is adjusted, which determines the flow of the working fluid through the external circuit.

A fuel manifold with injectors (1) is installed in the external circuit. Behind the fuel manifold there are flame stabilizers (2) and a spark plug for igniting the air-fuel mixture (3).

An example of the invention:

The air, pre-compressed in the low-pressure compressor, enters the external circuit of the engine (channel A). In this case, fuel is additionally supplied to the external circuit from the fuel manifold. Thus, the fuel, mixing with air in the area of the flame stabilizers, forms a fuel-air mixture, which is ignited by the spark plug of the air-fuel mixture (3). Combustion in the external circuit (4) takes place at a low combustion efficiency coefficient (not higher than 0.6). The remaining fuel decomposes under the influence of high temperature and forms a gas mixture, which, through the upper slot I and the lower slot II of the annular nozzle, formed by the annular walls and end walls of the two-dimensional gas-dynamic resonator (Fig. 3), enters the two-dimensional gas-dynamic resonator.

The area of the annular nozzle is the sum of the areas of slits I and II, and is critical, thereby ensuring a supercritical drop. At the exit from the annular nozzle, the flow turns perpendicular to the engine axis and accelerates to supersonic speed. Flows from the upper I and lower II slits, having a supersonic speed, collapse inside the cavity of a two-dimensional ring gas-dynamic resonator. When they collide, a shock wave (SW) is formed, propagating in all directions. Part of the wave reflected from the walls of the gas-dynamic resonator forms a reflected shock wave (RSW), which forms a focus line (f) (Fig. 4). On this line, the pressure and temperature rise to values sufficient for self-ignition of the prepared gas mixture and a detonation wave is formed, in which the remaining fuel is burned, thereby increasing the energy intensity of the gas jet. When passing through the cross-section of the annular nozzle, the OCW blocks the critical section. At the same time, interrupting the supply of the air-fuel mixture from the external circuit to the two-dimensional gas-dynamic resonator is a gas-dynamic valve. A shock wave with high pressure is followed by a rarefaction wave (BP) with low pressure, which opens the critical section. A new portion of the gas mixture enters the cavity of the resonator and the process is repeated, thereby organizing a pulsating flow with detonation combustion. Considering that a gas-dynamic valve is used as a shut-off device, i.e. There is no limitation on the frequency of pressure pulsations, which is inherent in mechanical valves; the pulsation frequency can be more than 20 kHz.

Flow pulsations due to additional compression in the hydrocarbon and combustion of residual fuel in a detonation cycle, which is close in efficiency to the Humphrey cycle (v=const) and gives an increase in thrust up to 25-35%. The SW is followed by BP and the thrust decreases somewhat, so for a pulsating flow the value of the averaged thrust is important. Thus, taking into account the high frequency of pulsations, the average increase in thrust is about 25%.

Claims (1)

Combined pulsating detonation output device of a turbojet engine with separate external and internal circuits, containing a tapering sound nozzle in the internal circuit, and in the external circuit in the area of the output section with a gap between the outer and inner walls of the outer circuit - a two-dimensional gas-dynamic resonator made in the form of a ring element with a resonator cavity, the traction wall of which is made in the form of a torus dissected in cross section, while on the outer and inner walls of the outer contour annular protrusions are formed, forming an annular gap with the corresponding outer and inner edges of the resonator cavity of a two-dimensional gas-dynamic resonator, characterized in that it additionally contains , installed in the external circuit, a fuel manifold with nozzles for supplying additional fuel to the flow before it enters through the annular nozzle in a two-dimensional gas-dynamic resonator.

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