RU52940U1 - CAMERA OF THE PULSING DETONATION COMBUSTION ENGINE - Google Patents

Abstract

The camera of a pulsating detonation combustion engine refers to pulsating air-jet engines with resonant combustion chambers, as well as to devices for burning fuel. The objective of the utility model is to increase the reliability of the detonation chamber. The technical result of the proposed chamber of a pulsating detonation combustion engine is an additional supply of energy to the working mixture at the time of its compression and eliminating the contact of the working mixture and detonation products. The problem is achieved in that the chamber of the pulsating detonation combustion engine contains a supersonic nozzle located in the housing and a coaxial resonator located in it in the form of a tube facing one open ring in the direction of expiration of the working fluid. In this case, an initiator is installed in the bottom part of the resonator, and the supersonic nozzle is made in such a way that the cross section of its inlet part is placed in the plane of transition of the inner cylindrical surface of the resonator to the conical one. The installation of the initiator in the region of the bottom of the resonator causes an additional supply of energy to the working mixture at the moment of its compression and the generation of a powerful shock wave, and the placement of the resonator and the supersonic nozzle in a certain way excludes the possibility of contact between the working mixture and detonation products. All this leads to increased reliability of the camera pulsating detonation combustion engine. The traction force is created due to the interaction of the detonation wave with the bottom of the resonator (traction wall), as well as due to the reactive force formed by the supersonic gas stream flowing through the nozzle. The total thrust impulse of a pulsating detonation combustion engine is directly proportional to the pulsation frequency and the pressure value on the bottom of the resonator. By changing these parameters, it is possible to regulate the thrust vector module.

Description

The utility model relates to pulsating jet engines with resonant combustion chambers, as well as to devices for burning fuel.

Known gas-jet generators Hartmann, operating in a pulsating mode of flow of the working fluid and are currently used as powerful acoustic emitters. With the discovery of the effect of increasing the temperature at the bottom of the resonator in fractions of a second, they began to be used to ignite combustible fuel mixtures, and also when high-temperature heat sources were needed (Lyakhov V.N. Podlubny V.V. Titarenko V.V. Impact of shock waves and jets on structural elements. M. Mechanical Engineering, 1989, 392 pp.). One of the variants of the structural embodiment of this effect is a ramjet engine (application of Germany N 4139338, IPC F 02 To 1/04 and F 02 To 7 / 10.1982). It creates traction due to the pulsed (pulsating) mode of expiration of the working fluid resulting from the combustion of the fuel-air mixture. This mode of operation is implemented in a resonant tube, creating a vacuum due to oscillations of the column of the working fluid, and air is supplied through annular slots. Despite the fact that this device has much in common with the claimed, it cannot realize the detonation mode of combustion.

The closest in technical essence and the achieved technical effect to the proposed technical solution is the "Camera of a pulsating detonation combustion engine" (RF patent No. 2084675, IPC F 02 K 15 / 02,1998.). It consists of a cavity and a supersonic nozzle mounted in a single housing. The development of this detonation chamber is based on the principle of operation of the Hartmann generator.

In this case, the resonator is made in the form of a tube closed on one side, and a cavity is formed between the inner surface of the casing and the outer surface of the nozzle, which is a displacement chamber, the output part of which is a critical section with a further transition to a supersonic nozzle with an external expansion with a truncated central body.

However, this device has a significant drawback, which consists in the low reliability of the device. This is due to the existence of a contact area between the detonation products and the working mixture. In turn, this causes ignition of the working mixture, which excludes its detonation. In addition, if in the initial

Since the moment of detonation is not excited, then in the future it will not occur. To eliminate this drawback, it is necessary to increase the likelihood of its occurrence at the initial moment of operation of the camera.

The objective of the utility model is to increase the reliability of the detonation chamber.

The technical result of the proposed chamber of a pulsating detonation combustion engine is an additional supply of energy to the working mixture at the time of its compression and eliminating the contact of the working mixture and detonation products.

The problem is achieved in that the chamber of the pulsating detonation combustion engine contains a supersonic nozzle located in the housing and a coaxial resonator located in it in the form of a tube facing one open ring in the direction of expiration of the working fluid. In this case, an initiator is installed in the bottom part of the resonator, and the supersonic nozzle is made in such a way that the cross section of its inlet part is placed in the plane of transition of the inner cylindrical surface of the resonator to the conical one.

The drawing shows a block diagram of the steering gear of the aircraft,

where: 1 - resonator;

2 - supersonic nozzle;

3 - case;

4 - gasket;

5 - bolts;

6 - a window in the case.

The camera of a pulsating detonation combustion engine consists of a resonator 1 and a supersonic nozzle 2 installed in a single housing 3.

The resonator 1 is designed to create shock waves and the excitation of detonation combustion. It is made in the form of a tube of cylindrical (slightly conical) shape, closed at one end and facing the open end towards the nozzle.

The supersonic nozzle 2 is designed to accelerate the working mixture to speeds with M> 2 and direct it into the interior of the resonator 1, as well as to disperse the gases flowing from the cavity of the resonator. The supersonic nozzle 2 is designed in such a way that the cross section of its inlet is located in the plane of transition of the inner cylindrical surface of the resonator to the conical.

The resonator 1 and the supersonic nozzle 2 are mounted coaxially in the housing 3 and in such a way that a cavity is formed between the inner surface of the housing and the outer surface of the nozzle, which is the mixing chamber “a” designed to create a working

mixtures. The output of the mixing chamber “a” is an annular critical section. On the end and side surfaces of the housing 3 are evenly placed inlet channels for the oxidizing agent (gas) and fuel (gas or liquid). Moreover, the axis of symmetry of the channels intersect for better mixture formation. The output of the working mixture from the chamber "a" is through the critical section of the external expansion nozzle.

The engine chamber is tuned to a predetermined mode of operation by changing the critical section area. This is achieved by selecting the thickness of the gasket 4, installed between the flanges of the housing 3 and the supersonic nozzle 2, which are fastened together by bolts 5.

The camera is a pulsating detonation combustion engine as follows.

When the fuel components are fed into the mixing chamber "a", a mixing process takes place in it. The resulting working mixture, flowing out through the critical section, acquires supersonic speed. The camera always works in steady state. This is because the pressure in the cavity "a" is equal to the pressure of the environment due to communication with it by windows 6.

Accelerated to a speed M> 2, the working mixture enters the internal cavity "b" of resonator 1, in which the oscillatory process is excited with the formation of shock waves (Hartmann effect), which in turn generate detonation waves. When these waves collide with the closed end of the resonator, reflected shock waves form. In this case, a sharp increase in temperature and pressure occurs (Springer effect). The resonator parameters are calculated so that the working mixture located in the region of the bottom detonates. To increase the reliability of the camera at the time of the collision of the working mixture with the bottom of the resonator, initiator 7 is triggered, causing its reliable detonation due to additional energy supply and the generation of a powerful shock wave.

The resulting detonation wave, reflected from the bottom of the resonator 1, rushes to its exit, blocking the path of the incoming working mixture. The detonation wave, meeting with the supersonic flow of the working mixture, forms a "gas shutter", which blocks the path of the supersonic flow of the working mixture into the resonator 1. Subsequently, the detonation products expiring through the annular gap formed between the nozzle 2 and the resonators 1, expand, which leads to pressure reduction. When the pressure of the detonation products and the working mixture are equalized, a “gas lock” is opened at the nozzle exit and the detonation wave rushes out through the “g” cavity. Reliable camera operation is ensured by the separation of detonation products and the working mixture by the walls

supersonic nozzle 2. A new portion of the working mixture rushes into the resonator 1 and the process is repeated again.

The traction force is created due to the interaction of the detonation wave with the bottom of the resonator (traction wall), as well as due to the reactive force formed by the supersonic gas stream flowing through the nozzle. The total thrust impulse of a pulsating detonation combustion engine is directly proportional to the pulsation frequency and the pressure value on the bottom of the resonator. By changing these parameters, it is possible to regulate the thrust vector module.

Thus, the installation of the initiator in the region of the bottom of the resonator causes an additional supply of energy to the working mixture at the time of its compression and the generation of a powerful shock wave, and the placement of the resonator and the supersonic nozzle in a certain way excludes the possibility of contact between the working mixture and detonation products. All this leads to increased reliability of the camera pulsating detonation combustion engine.

Claims (1)

A chamber of a pulsating detonation combustion engine containing a supersonic nozzle located in the housing and coaxially located in the form of a tube facing one open ring towards the expiration of the working fluid, characterized in that an initiator is installed in the bottom of the resonator, and the supersonic nozzle is designed in such a way that the cross section of its inlet is located in the plane of transition of the inner cylindrical surface of the resonator to the conical.