RU2674117C1 - Stand liquid rocket engine with continuous spin detonation - Google Patents

Abstract

FIELD: test technology.

SUBSTANCE: invention relates to the field of testing, in particular, bench tests of the modes of operation of LRE operating in continuous detonation mode on a fuel mixture consisting of gaseous oxygen and kerosene. Invention is a bench LRE with an annular detonation combustion chamber, a mixing head, an initiator, a jet nozzle and measuring equipment. Distinctive features of the declared LRE is that the mixing head is made in the form of an annular gap in the firing base for the supply of oxidant, on both sides of which the fuel supply nozzles are located at an acute angle. Another difference from the known solutions is that the motor housing and the chamber are made of two layers, the inner layer is made of a strong alloy, and the outer one is made of a highly heat-conducting alloy.

EFFECT: invention provides an increase in the maximum working pressure.

9 cl, 2 dwg

Description

Technical field

The invention relates to bench rocket engines operating in continuous detonation mode on a fuel mixture consisting of gaseous oxygen and kerosene.

State of the art

To date, the main scheme for organizing detonation combustion is known: in detonation waves continuously circulating in the tangential direction across the annular combustion chamber (spin detonation). However, there are still no experimental data confirming the effectiveness of this method. Direct comparison of the measured traction characteristics of jet engines with pulse detonation and continuous combustion was not performed due to the fact that the tests lasted no more than one second.

Patent research on rocket engines with spin detonation combustion revealed three foreign inventions and one Russian technical solution that are relevant to the subject.

So, for example, in the invention of US No. 3240010, 1966, a detonation combustion chamber is formed between an annular mixing head and a plug inserted into the engine housing. The annular combustion chamber contains a mixing head in which two pairs of annular jet nozzles are made. The engine also contains a knock initiator, through the damper feeds the fuel mixture into the annular combustion chamber.

In the invention US No. 3336754, 1967, the engine casing is made in the form of an annular or ellipsoidal shape, which is closed by a disk on one side and closed by an annular shell, in which an annular combustion chamber is formed, formed by two annular inserts in which jet nozzles are made oxidizing agent and fuel. The exit of combustion products from that annular chamber creates engine thrust. A continuous detonation wave is generated in the annular chamber by introducing combustion products from the detonation initiator.

Known bench rocket engine with spin detonation mode of combustion (US patent No. 8544280, 01.10.2013, IPC F02K 5/02 - 7/02), which includes an annular combustion chamber in which a mixing head is connected on one side and the mixing head is connected on the other hand jet nozzle. An annular combustion chamber is formed by two coaxial cylinders with the formation of an annular gap between them. The mixing head consists of an annular channel through which fuel is supplied from the inlet side of the engine, and an element ensuring the twisting of the gaseous oxidizer flow - an impeller, a fan, or a blade device. A ring is installed between the annular combustion chamber and the mixing head to narrow the gap between the cylinders in such a way as to prevent the detonation wave from slipping from the annular combustion chamber into the mixing chamber when the engine is running. The jet nozzle is formed by a conical centering body attached to the other end of the outer cylinder. The annular combustion chamber has channels through which the pressure and temperature of the fuel mixture inside the combustion chamber are measured, and a channel for introducing an electrode for igniting the mixture.

Also known is the Russian bench-top rocket engine (Reports of the Academy of Sciences, 2014, volume 459, No. 6, pp. 711-716, “Experimental evidence of the energy efficiency of Zeldovich’s thermodynamic cycle”, auth. Frolov S.M. et al.), Including an annular combustion chamber to which a mixing head is attached on one side and a jet nozzle on the other. An annular combustion chamber is formed by two coaxial cylinders with the formation of an annular gap between them. The mixing head consists of a thin disk with a pointed edge attached to the end face of the inner cylinder of the combustion chamber, so that between the edge and the outer wall of the combustion chamber there is an annular gap of 1 mm wide, and 72 radial small holes in the outer wall of the combustion chamber located in one transverse section at an axial distance of 0.5 mm downstream. Oxygen enters the combustion chamber in the axial direction through the annular gap of the mixing head, and hydrogen through the indicated radial holes. The jet nozzle is formed by a conical central body with an apex angle of 50 ° attached to the other end of the inner cylinder. Near the output section of the outer cylinder with a gap is an electrode that provides ignition of the fuel mixture. Due to high thermal loads, the housing of the combustion chamber is water-cooled and made of copper. Prototype.

However, the known technical solution does not provide the required life of the combustion chamber at a pressure of more than 2 kgf / cm ² and the duration of the fire test for more than 2 seconds.

Disclosure of invention

The objective of the invention is to create a rocket engine operating in continuous spin detonation mode at sufficiently high pressures in the combustion chamber (from 16 kgf / cm ² or more).

This problem is solved due to the fact that in a bench rocket engine with continuous spin detonation, which includes an annular combustion chamber, to which a mixing head is attached, and a jet nozzle is connected on the other hand, the annular combustion chamber is formed by two coaxial cylinders with the formation of an annular gap between them

- the mixing head is installed along the axis of the engine and is made of an annular fire bottom, in which an annular slit nozzle for supplying an oxidizer is made in the middle, on both sides of which there are radial jet nozzles for supplying fuel, the axes of which are directed at an acute angle to the slot nozzle, and the exit is the mixing head is connected to an annular detonation chamber;

- the outer casing of the annular chamber consists of an external power wall made of a high-strength alloy and an inner fin wall made of a high-heat-conducting alloy interconnected by soldering;

- in the housing of the annular chamber there are three openings hermetically passing through both its walls, one for supplying the combustible mixture from the initiator of detonation combustion into the annular chamber of detonation combustion, the other two for recording pressure in the annular chamber;

- the inner motor casing consists of an outer smooth wall made of a highly heat-conducting alloy, an inner ribbed wall - of a durable heat-conducting alloy, interconnected by soldering.

Other differences are that:

- that the initiator of detonation combustion is made in the form of a chamber having a fitting for supplying an oxidizer and fuel and an outlet channel for supplying combustion products to the annular chamber, as well as a spark plug;

- the value of the acute angles along which the axis of the slender nozzles are inclined lie within 40 ° -50 °;

- the outer power shell of the outer casing is made of VNS-16 alloy, and the inner fire wall is made of copper or BrX08 copper alloy;

- the outer shell of the inner case is made of copper or BrX08 copper alloy, and the inner shell of this case is made of alloy 273;

- the body of the initiator of detonation combustion is made of steel EP-202;

- the oxidizing agent is air;

- the oxidizing agent is gaseous oxygen;

- fuel is liquid kerosene.

List of drawings

In FIG. 1 shows a longitudinal section of the proposed engine; in FIG. 2 shows a fragment of the cross section of the mixing head.

Description of the invention

The engine includes (Fig. 1) a mixing head 1, an outer casing 2, an inner casing 3, a knock initiator 4, an oxidizer supply line 5, a fuel supply line 6, a coolant supply pipe to the outer case 7, a coolant drain pipe 8, the coolant supply line to the inner case 9, the coolant drain line from the inner case 10 and the mount 11.

The chamber (Fig. 1) consists of a combustion chamber 12 and a nozzle 13.

The combustion chamber is an annular channel formed by the outer and inner bodies 2.

The nozzle is a profiled contour formed by the outer and inner bodies.

The mixing head 1 (Fig. 2) consists of a firing bottom 14, in which an annular channel 15 and a plurality of holes 16 are made on both sides of the annular channel of the slotted nozzle directed at an acute angle of 40 ... 50 ° towards the annular channel, and the housing 17 made from high-strength material.

The outer casing 2 consists of an outer shell 18 made of a high-strength alloy, for example, VNS-16, and an inner fin wall 19 made of a high-heat-conducting alloy, for example, copper or BrX08 copper alloy, interconnected by soldering. The housing has three holes passing through both walls, 20 for supplying the combustible mixture from the initiator to the combustion chamber and 21 for two pressure sensors recording the process and pressure values in the combustion chamber 12.

The inner casing 3 consists of a smooth shell 23 made of a highly heat-conducting alloy, for example, of copper or BrX08 copper alloy, and a finned shell 22 made of a durable heat-conducting alloy, for example, alloy 273, interconnected by soldering.

The initiator of detonation combustion 4 consists of a combustion chamber 24, two nozzles for supplying fuel 25, two nozzles for supplying oxidizer 26, a channel for supplying combustion products 27 to the combustion chamber of the demonstration sample and the spark plug 28. The body of the combustion chamber of initiator 29 is made of EP-202 steel uncooled; near the end of the candle 28, two holes 30 for the injection of fuel and two holes for the injection of the oxidizer are made perpendicular to the axis of the chamber.

The lines for supplying fuel components, for supplying and discharging coolant, for example, water, are made in such a way that the connection with bench lines is made detachable, while the supply and discharge of coolant for the inner case are made in the form of two coaxially arranged pipes.

The mount 11 is a disk in which there are six holes used for mounting to a bench frame.

The design of the cooling paths of the combustion chamber in combination with the use of highly heat-conducting and high-strength alloys makes it possible to ensure the operability of the combustion chamber at higher values of the energy characteristics of the engine compared to the known ones. The presented mixture formation scheme allows one to shorten the mixing period of the components, which contributes to the emergence of stable combustion with detonation waves.

Engine operation

First, fluid is supplied to the cooling ducts of the outer 2 and inner 3 casings.

To cool the outer casing, water through the fittings 7 and the collector 34 enters the cooling path and, passing it, through the collector 35 and the fittings 8 is discharged into the bench containers.

To cool the inner case, water through four nozzles 9, path 36 and openings 37 enters the cooling path, and passing it through paths 38, 39 and four nozzles 10 is discharged into the bench containers.

Gaseous oxygen (air) with ambient temperature from the bench line enters through four nozzles 5 into the manifold 32, from which through the annular gap 15 (see Fig. 2), enters the annular combustion chamber 12; simultaneously, oxygen through two nozzles 26 enters the combustion chamber 24 of the initiator.

Kerosene through two nozzles 6 enters the manifold 33 and then through holes 16 (see Fig. 2) 0.35 mm in diameter is injected into the annular combustion chamber 12, where it is mixed with the incoming oxygen; at the same time kerosene through two nozzles 25 enters the combustion chamber of the initiator.

To ignite a mixture of oxygen with kerosene in the initiator, a candle 28 is used.

Oxygen is injected into the combustion chamber of the initiator 24 through 2 holes, kerosene is injected through 2 holes perpendicular to the axis of the initiator chamber, where the incoming components are mixed.

A special electric candle is used to ignite the mixture in the initiator chamber 24.

The combustion products from the initiator through the hole 20 enter the annular combustion chamber 12 and ignite the mixture of oxygen and kerosene located there and, accordingly, initiate a spin detonation wave. After the occurrence of the detonation wave, the flow of kerosene through the initiator is turned off, only oxygen is supplied to the annular combustion chamber 12 through the initiator.

The implementation of the annular combustion chamber from two coaxial sufficiently strong cooled buildings allows you to increase the pressure of the combustion products in the chamber to 16 kgf / cm ² and above and increase the duration of the fire test up to 30 seconds or more.

The implementation of the mixing head in the form of an annular firing base with an annular slit nozzle for supplying an oxidizer in it, on both sides of which radial jet nozzles for supplying fuel are made, makes it possible to obtain the required mixture of components in the immediate vicinity of the firing base, which ensures smooth engine starting.

Industrial application

The proposed engine design allows the development of the combustion process with detonation waves in a wide range of engine operation parameters, followed by the use of mining results to create industrial designs.

Claims (9)

1. A bench-top liquid rocket engine with continuous spin detonation, including an annular combustion chamber, to which a mixing head is attached, and a jet nozzle on the other hand, an annular combustion chamber is formed by two coaxial cylinders with the formation of an annular gap between them, characterized in that the mixing head is installed along the axis of the engine and is made of an annular fire bottom, in which an annular slit nozzle for supplying an oxidizer is made in the middle, on both sides of which the radial jet nozzles of the fuel supply are made, the axes of which are directed at an acute angle to the slot nozzle, and the outlet of the mixing head is connected to the annular detonation chamber, while the outer housing of the annular chamber consists of an external power shell made of high-strength alloy and an internal finned shell made of a highly heat-conducting alloy, interconnected by soldering, while in the case of the annular chamber there are three holes tightly passing through both of its shells, one for the supply of the combustible mixture from the initiator of detonation combustion into the annular chamber of detonation combustion, the other two are for recording pressure in the annular chamber, while the inner engine casing consists of an outer smooth shell made of a highly heat-conducting alloy, an inner finned shell of a durable heat-conducting alloy connected between by soldering. 2. The engine according to claim 1, characterized in that the initiator of detonation combustion is made in the form of a chamber having fittings for supplying an oxidizer and fuel and an outlet channel for supplying combustion products to the annular chamber, as well as an spark plug. 3. The engine according to claim 1, characterized in that the value of the acute angles along which the axis of the jet nozzles are inclined lie within 40 ° -50 °. 4. The engine according to claim 1, characterized in that the outer power shell of the outer casing is made of VNS-16 alloy, and the inner fire wall is made of copper or BrX08 copper alloy. 5. The engine according to claim 1, characterized in that the outer shell of the inner casing is made of copper or BrX08 copper alloy, and the inner shell of this casing is made of alloy 273. 6. The engine according to claim 1, characterized in that the detonation combustion initiator housing is made of EP-202 steel. 7. The engine under item 1, characterized in that the oxidizing agent is air. 8. The engine according to claim 1, characterized in that the oxidizing agent is gaseous oxygen. 9. The engine under item 1, characterized in that the fuel is a liquid kerosene.

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