RU2770975C2 - Apparatus for laser ignition of fuel components in a combustion chamber or gas generator of a liquid rocket engine - Google Patents

Abstract

FIELD: engine building.

SUBSTANCE: invention relates to the field of liquid rocket engines (LREs), namely to systems for ignition of non-flammable fuel components in combustion chambers or in a gas generator. The apparatus for laser ignition of fuel components in a combustion chamber or gas generator of a liquid rocket engine includes a laser emission focusing unit made in the form of a tube with a flange at one end and a focusing lens at the other end, wherein the apparatus comprises a cylindrical body with a through axial channel, wherein a flange is made on one side of the body and a cylindrical mixing chamber is attached on the other side of the body, wherein the tube of the focusing unit is inserted into the through axial channel of the cylindrical body and tightly connected thereto, additionally, channels for supplying oxidiser and fuel into the mixing chamber are made in the body, the cylindrical body together with the focusing unit are secured on the outer bottom of the mixing head by flanges, and the mixing chamber is secured on the firing bottom of the mixing head via pylons fixed on the cylindrical surface of the mixing chamber, and the laser beam is focused so that optical breakdown is executed in the inner cavity of the cylindrical mixing chamber filled with a mixture of fuel components. Oxidiser is supplied to the mixing chamber through tangential holes made on the outer surface of the body of the apparatus and through an annular channel, and fuel is supplied to the mixing chamber through radial holes made in a branch pipe attached to the outer surface of the body of the apparatus through an annular channel, tangential holes, and an annular additional channel.

EFFECT: invention increases the reliability of ignition of liquid non-flammable fuel components in a combustion chamber or gas generator of an LRE.

3 cl, 2 dwg

Description

The invention relates to the field of liquid propellant rocket engines (LRE) and can be used for repeated launch of combustion chambers or gas generators operating on liquid propellant components.

One of the main problems that arise in the development of combustion chambers and gas generators of LRE operating on liquid non-self-igniting fuel components is the creation of an ignition system that ensures their reliable start and has minimal dimensions and weight.

Prior Art

A known method of igniting fuel components in a liquid-propellant rocket engine and a laser ignition device for implementing this method, which consists in the fact that in the cavity of one of the nozzles of a multi-injector mixing head, by focusing one or more lenses of the laser beam, an optical breakdown is carried out with ignition of the mixture of fuel components in this cavity of the nozzle and subsequent ignition, total fuel consumption from the mixing head, combustion products from the nozzle (RF patent No. 2580232, IPC: F02K 9/95 - prototype).

The main disadvantage of this method of igniting fuel components is the need to install a focusing device in the cavity of the mixing head filled with an optically transparent fuel component.

Another disadvantage is the unreliable fastening of the tubular focusing unit to the outer bottom of the mixing head (cantilever type of fastening). Strong vibrations that occur during the operation of the LRE can lead to breakage of the body of the tubular focus assembly.

The objective of the invention is to eliminate these shortcomings and ensure reliable ignition of liquid non-self-igniting fuel components in the combustion chamber or gas generator of the rocket engine.

Disclosure of invention

The solution to this problem is achieved by the fact that the device for laser ignition of fuel components in the combustion chamber or gas generator of a liquid-propellant rocket engine includes a laser radiation focusing unit made in the form of a tube with a flange at one end and a focusing lens at the other end, and the device contains a cylindrical body with a through axial channel, while a flange is made on one side of the body, and a cylindrical mixing chamber is attached to the body on the other side, and the tube of the focusing unit is inserted into the through axial channel of the cylindrical body and is hermetically connected to it, in addition, oxidizer supply channels are made in the body and fuel into the mixing chamber, the cylindrical body, together with the focusing unit, is attached to the outer bottom of the mixing head with the help of flanges, and the mixing chamber is attached to the firing bottom of the mixing head through pylons fixed on the cylindrical surface of the mixing chamber, and the focusing laser The black beam is designed in such a way that the optical breakdown is carried out in the internal cavity of the cylindrical mixing chamber filled with a mixture of fuel components.

Other differences are:

- the oxidant is supplied to the mixing chamber through tangential holes made on the outer surface of the device body and through the annular channel;

- fuel is supplied to the mixing chamber through radial holes made in the branch pipe attached to the outer surface of the device housing through an annular channel, tangential holes and an additional annular channel.

The proposed design of the device for laser ignition of fuel components in the combustion chamber or LRE gas generator, due to its distinctive features, provides a solution to the set technical problem - ensuring reliable ignition of liquid non-self-igniting fuel components in the LRE combustion chamber or gas generator.

The essence of the invention is illustrated in the drawings, where in Fig. 1 shows a longitudinal section of the gas generator, FIG. 2 is a longitudinal section of the device.

The proposed device can be used as part of a LRE gas generator having the following design.

The gas generator consists of a mixing head 1 and a body 2.

The mixing head 1 of the gas generator consists of nozzles 3 evenly spaced along concentric circles, a firing bottom 4, a middle bottom 5 and an outer bottom 6.

The gas generator housing 2 consists of a spacer 7 cooled by an oxidizer, which forms the cavity of the chamber 8 and a spherical collector 9. On the axis of the mixing head 1 of the gas generator, a device for laser ignition of fuel components in the combustion chamber or gas generator of the LRE 10 is installed, containing a cylindrical housing 11 with a flange 12, and a through axial channel 13. At the end of the housing 11, a cylindrical mixing chamber 14 is installed. The device also contains a focusing unit for laser radiation 15, made in the form of a tube 16 with a flange 17, the tube of which is inserted into the through axial channel 13 of the housing 11. A laser is installed on the end surface of the flange 17 eighteen.

On the inner surface of the mixing chamber 14, tangential holes 19 are evenly located around the circumference, through which the oxidizer is supplied to the mixing chamber 14. In the outlet part of the mixing chamber, longitudinal grooves 20 are made, located between the pylons 21. At the same time, an annular channel is made between the housing 11 and the mixing chamber 22, going into the mixing chamber 14.

A branch pipe 23 is fixed on the outer surface of the housing 11, in which radial holes 24 are made, through which fuel is supplied to the mixing chamber 14. At the same time, the outlet from the holes 24 is connected to the annular channel 25, which is connected through the tangential holes 26 to the annular additional channel 27, which is connected to the mixing chamber 14.

The focusing unit of laser radiation 15 contains a focusing lens 28 fixed on the end of the tube 16. In this case, the focus 29 of the lens 28 is located in the volume of the mixing chamber.

In the proposed device, the housing 11, the focusing unit 15 through the flanges 12 and 17, are hermetically connected to the outer bottom 6 of the mixing head 1 of the chamber 8.

This makes it possible to exclude breakage of the focusing unit at high vibrations and to increase the reliability of the proposed device. In addition, the use of a tubular focusing assembly at the inlet to the mixing chamber makes it possible to protect the focusing lens from contact with the fuel components entering the mixing chamber.

Device operation

The fuel enters the cavity formed by the outer bottom 6 and the middle bottom 5 of the mixing head 1 and is distributed between the nozzles 3 and the device 10. The fuel enters the device 10 through the radial holes 24, the annular channel 25, the tangential holes 26 and then goes to the additional annular channel 27 , and from it the fuel enters the mixing chamber 14.

The oxidizer enters the collector 9 and is distributed between the housing 2 and the mixing head 1 of the gas generator.

From the cavity of the mixing head formed by the middle bottom 5 and the firing bottom 4, the oxidizer enters the nozzles 3 and the device 10. cavity of the mixing chamber 14.

In the cavity of the mixing chamber 14, the fuel components are mixed with each other. The laser beam emerging from the laser 18 and passing through the focusing unit 15 is focused by the lens 28, while the focus of the radiation is 29, while the focus of the laser radiation is in the volume of the mixing chamber. After that, the laser 18 is turned on, as a result of which an optical breakdown occurs in the mixing chamber with the appearance of an optical spark plasma that ignites the fuel mixture. The resulting high-temperature combustion products exit the mixing chamber and through the longitudinal grooves, together with oxygen, enter the combustion chamber 8 of the gas generator and ignite the fuel components in the combustion chamber.

Industrial Application

The proposed technical solution will find application in LREs operating on non-self-igniting fuel components, such as liquid oxygen with kerosene, and will ensure their reliable ignition in the LRE combustion chamber or gas generator.

Claims (3)

1. A device for laser ignition of fuel components in a combustion chamber or gas generator of a liquid-propellant rocket engine, including a laser radiation focusing unit made in the form of a tube with a flange at one end and a focusing lens at the other end, characterized in that the device contains a cylindrical body with a through an axial channel, while a flange is made on one side of the body, and a cylindrical mixing chamber is attached to the body on the other side, and the tube of the focusing unit is inserted into the through axial channel of the cylindrical body and is hermetically connected to it, in addition, channels for supplying an oxidizer and fuel into the mixing chamber, the cylindrical body, together with the focusing unit, is attached to the outer bottom of the mixing head with the help of flanges, and the mixing chamber is attached to the firing bottom of the mixing head through pylons fixed on the cylindrical surface of the mixing chamber, and the laser beam is focused as follows in such a way that the optical breakdown is carried out in the internal cavity of the cylindrical mixing chamber filled with a mixture of fuel components. 2. The device according to claim 1, characterized in that the oxidant is supplied to the mixing chamber through tangential holes made on the outer surface of the device body and through the annular channel. 3. The device according to claim 1, characterized in that the supply of fuel to the mixing chamber is carried out through radial holes made in the pipe attached to the outer surface of the device body through an annular channel, tangential holes and an annular additional channel.

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