RU2622141C1 - Solid fuel rocket engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: solid fuel rocket engine contains two casing halves, front and rear, equipped with front and rear end-burning half-charges, the open face ends of which face each other, and a nozzle cluster and ignitor which are gas-connected with the casing halves. The nozzle cluster is made as a single central nozzle gas-connected to the face ends of the half-charges via a flow pipe running through the rear half-charge. The rear half-charge is separated from the flow pipe which runs inside an armoured channel in the rear half-charge. The central nozzle is installed on a mounting flange which is on the rear casing half.

EFFECT: invention allows decreasing the engine transverse dimensions, increasing the total burn, avoiding thermal effect on the rear casing half, simplifying the structure of the engine and improving its design for manufacturability.

7 cl, 1 dwg

Description

The invention relates to rocket technology and can be used to create a rocket engine of solid fuel with a long operating time.

It is known that to increase the operating time of a rocket engine of solid fuel, by increasing the thickness of the burning arch, end-combustion charges are used [Erokhin B.T. Theory of internal chamber processes and design of solid propellant rocket engines: a textbook for higher technical educational institutions. M .: mechanical engineering. 1991 .-- 560 pp., Ill., Page 15, fig. 1.7]. When the end-combustion charge burns out during engine operation, the center of mass of the engine in question (and the rocket) is substantially shifted along the longitudinal axis, which in some cases is unacceptable.

The closest in technical essence and the achieved positive effect to the proposed invention is an engine with two end charges, in which “to eliminate the displacement of the center of mass of the rocket during engine operation, the end charge is replaced by two end-charge semi-charges burning towards each other” [D. Abugov ., Bobylev V.M. Theory and calculation of solid propellant rocket engines. Textbook for engineering universities. - M.: Mechanical Engineering, 1987. - 272 p.: Ill., Page 86, Fig. 5.7]. A solid fuel rocket engine contains two (front and rear) half-shells equipped with front and rear half-charges of face combustion, the open ends of which are facing each other. The nozzle block and the igniter are gas-connected to the half-bodies. In this case, the nozzle block is formed by several (at least two) side nozzles evenly spaced around the circumference of the half-housing, mounted on the cylindrical surface of the half-housing at an angle to the longitudinal axis of the engine. The considered circuit has several disadvantages:

- side nozzles increase both the transverse dimensions of the engine and the aerodynamic drag of the rocket;

- the total thrust impulse and engine thrust from the side nozzles are less than from the central nozzle, because the indicated values are determined by the projection of the thrust from the lateral nozzles installed at a certain angle onto the longitudinal axis of the engine (determined by the cosine of the angle of installation of the lateral nozzles, and the cosine of this angle is less than unity);

- increased thermal effect on the rear half-housing from the jet of combustion products from the side nozzles. With an increase in the angle of inclination of the side nozzles, the thermal effect decreases, but the total thrust momentum and thrust also decrease;

- increased eccentricity of the thrust from the side nozzles (which is many times greater than from the central nozzle);

- increased mass of the engine structure containing non-axisymmetric (i.e., rather heavy) mating nodes of the side nozzles with the cylindrical body. Note that even in the absence of these nodes, the mass of the construction of two nozzles is almost two times more than one (with the same total critical cross-sectional areas);

- when attaching the front half-charge in the half-shell, compensating elements are required that reduce the stress-strain state of the half-charge to an acceptable level. The design of the compensating elements of the end monolithic charge is quite complex and capricious in mining;

- a design containing non-axisymmetric interface nodes of the side nozzles with a cylindrical body is complex, non-technological.

The technical task of the present invention is to reduce the transverse dimensions of the engine and decrease the aerodynamic drag of the rocket, increase the total thrust impulse, eliminate thermal effects on the rear half-hull, reduce the eccentricity of thrust, reduce weight, simplify the design and simplify the attachment of the semi-charge, improve the manufacturability of the structure.

The essence of the invention lies in the fact that in a rocket engine of solid fuel containing two (front and rear) half-shells, equipped with front and rear half-charges of end combustion, the open ends of which are facing each other, the nozzle block and the ignitor, gas-connected with the half-shells, the nozzle block is made in the form of one central nozzle, gas-connected with the open ends of the half-charges by a flow tube passed through the rear half-charge, while the central nozzle is mounted on a mounting flange made on the back m half-hull. A flow tube may be passed through the front half charge, and the front half shell with the front half charge and the rear half shell with the rear half charge can be interchangeable. The igniter can be placed inside the flow pipe on the cover mounted on the mounting flange. The flow tube can be attached to the half-shell through a process connector. The rear half charge can be separated from the flow tube, which passes inside the channel made in the rear half charge, and the surface of the channel is covered with an armor. A gap can be made between the back half charge and the feed pipe, and a release layer is placed in the gap between the reservation and the feed pipe. The length of the flow tube may be less than the length of the channel of the rear half charge. The thickness of the flow tube or armor can be made variable, increasing to the mounting flange.

The technical result is achieved due to the fact that the flow tube passed through the rear half-charge provides gas connection of the intracameral volume between the open ends of the half-charges with the nozzle mounted on the mounting flange made on the rear half-shell. This makes it possible to make the nozzle block in the form of one central nozzle. And this, in turn, leads to the solution of these technical problems of the invention. One central nozzle provides a reduction in the transverse dimensions of the engine, a decrease in the aerodynamic drag of the rocket and the exclusion of thermal effects on the rear half-shell. The total thrust momentum and engine thrust are determined by the projection of the thrust from the nozzles onto the longitudinal axis of the engine. Due to the fact that the central nozzle is directed along the axis of the engine, the total thrust momentum and engine thrust are maximized (the cosine of the zero angle is equal to unity). The eccentricity of the thrust from the axisymmetric nozzle (gas path) is significantly less than from the side nozzle, the gas path of which is formed by several sections, mating with each other at an angle. The mass of the axisymmetric design of the engine is less than the mass of the non-axisymmetric (i.e., rather heavy) junctions of the side nozzles and the cylindrical body. The additional mass of the supply pipe is compensated by the fact that the mass of the construction of two nozzles is almost two times greater than one nozzle (with the same total critical cross-sectional areas). Mounting the igniter on the cover mounted on the mounting flange, and placing it inside the flow tube provides a small mass of attachment points of the ignitor, small dimensions, simplicity of design. Simplification of the design, improvement of its manufacturability is achieved as follows. Firstly, the nodes and parts have an axisymmetric shape, which already leads to a simplification of the design. Secondly, the front and rear half-shells, equipped with front and rear half-charges, are made interchangeable. The interchangeability of half-charges and half-shells reduces the range of technological equipment and the amount of necessary development. Thirdly, the feed pipe is attached to the half-shell by means of a technological connector, which enables the manufacture of half charges separately from the feed pipe. Simplification of the fastening of the semi-charge is achieved as follows. Both the plug-in and the strongly bonded end-combustion charge must be reserved on a cylindrical surface. With a long working time, the thickness of the armor is required sufficiently large, which affects the engine parameters. When gluing a reservation with a case, the reservation turns into a heat-protective coating of the case. At the same time, the thickness of the specified heat-protective coating of the housing can be made variable by halving its weight. However, with the indicated bonding of the reservation with the housing, during operation of the product at various temperatures, the stress-strain state in the charge bonded to the housing is unacceptable by the criterion of charge strength. An unloading charge (half-charge) element (unfastening) is required, which is known for a monolithic end charge, but rather complicated. The simplest charge-releasing element is a longitudinal through channel in the charge. Thus, the channel not only ensures the placement of the flow tube, but also serves as a half-charge release element that reduces the level of the stress-strain state in the half charge during operation to an acceptable value. Those. the channel simplifies the fastening of the semi-charge in the half-shell. In order for the channel to fulfill its function as an element detaching a half charge, the half charge must be separated from the feed pipe, and a gap is required between the reservation and the feed pipe. A release layer is placed in said gap to prevent sticking of the semi-charge portions on the flow tube. To prevent half-heating by the flow of combustion products in the flow tube, the thickness of the flow tube or armor is made variable, increasing towards the mounting flange. To reduce the mass, the length of the flow tube is less than the length of the reserved channel of the rear half charge, because for some time (until it warms up) the reservation serves as a supply pipe.

This technical solution is unknown from the patent and technical literature.

The invention is illustrated by the figure, which shows a rocket engine of solid fuel in the context.

The solid fuel rocket engine contains two half-hulls: the front half-hull 1 and the rear half-hull 2. Half-hulls 1 and 2 are respectively equipped with front (3) and rear (4) end-combustion half-charges, the open ends 5 of which are facing each other (into the intracameral volume 6). A flow pipe 7 is passed through the rear half charge 4. A mounting flange is made on the rear half-housing 2. The central nozzle 9 is mounted on a mounting flange 8 made on the rear half-housing 2. The flow pipe 7 connects the chamber 6 with the central nozzle 9. Through the front half-charge 3, By analogy with the rear half charge 4, the flow tube 7 is skipped. In this case, the front half shell 1 and the rear half shell 2, equipped with the front half charge 3 and the rear half charge 4, respectively, are made interchangeable. A mounting flange 8 is made on the front half housing 1 (as well as on the rear 2). The flow tube 7 is attached to the half housing (1, 2) by means of a process connector 10. A cover 11 is mounted on the mounting flange 8 of the front half housing 1. The igniter 12 is located inside the flow pipe 7 on the cover 11 mounted on the mounting flange 8. The flow pipe 7 passes inside the channel 13 of the rear half charge 4, thereby the rear half charge 4 is separated from the flow pipe 7. The surface of the channel 13 is covered with a reservation 14. Between the rear half charge 4 and the flow pipe 7 is made gap 15. In the gap 15 between the reservation 14 and the flow tube 7, a release layer 16 is placed (for example, a fluoroplastic film). Due to the interchangeability of the half-shells 1, 2 and half-charges 3, 4, the pairing of the flow tube 7 with the front half-charge 3 is similar to the above pairing with the rear half-charge 4. The length of the flow pipe 7 is less than the length of the reserved channel 13 of the rear half-charge 4. The thickness of the flow pipe 7 or reservation 14 is made variable increasing to the mounting flange 8.

The device operates as follows. During storage and operation of the engine when the volumetric average temperature of the semi-charge deviates from the equilibrium value, the stress-strain state of the semi-charges 3, 4 is intensified. Separate stresses arise at the charge-case interface and tangential stresses on the surface of channel 13. With a sufficient diameter of channel 13 (more than 0.15 of the outer diameter of the semi-charge 3, 4), these voltages do not exceed the permissible values. Channel 13 also unloads half-charges 3, 4 during engine operation during deformation of half-shells 1, 2 from intracameral pressure. Thus, the appearance of cracks in the semi-charges during their operation and operation is excluded. The rocket engine starts when the igniter 12 is triggered, the combustion products of which through the flow pipe 7 enter the intracameral volume 6. The open ends 5 of the front (3) and rear (4) half charges are ignited, and as the half charges 3, 4 burn out, they move, increasing the intracameral volume 6. The products of combustion of semi-charges 3, 4 from the intracameral volume 6 through the flow pipe 7 come to the central nozzle 9 and flow out of it, creating engine thrust directed along the axis of the central nozzle 9. In the course of the flow of products Rania flow pipe 7 by its heating occurs. Due to the fact that the thickness of the flow tube 7 or the armor 14 is made variable, increasing towards the mounting flange 8, heating of the lengthwise sections of the flow tube 7 to its entire thickness occurs later than the burning of the corresponding sections of the half charges 3, 4. There is no intense heating the supply pipe 7 and the reservation 14 from the side of the gap 15, forming a stagnant zone. The first portion of the hot combustion products that arrived at the start of the engine in the stagnant zone, gives part of the heat to the reservation 14 and the flow tube 7, lowering its temperature. This portion of the cooled combustion products prevents the further flow of new (i.e., hot) gas into the stagnant zone of the gap 15. Thus, the necessary thermal protection of the semi-charges 3, 4 is provided (both from the side of the flow part of the flow pipe 7 and from the side of the gap 15) .

Technical and economic efficiency of the invention, compared with the prototype, which is selected as an engine with two end charges [Abugov DI, Bobylev V.M. Theory and calculation of solid propellant rocket engines. Textbook for engineering universities. - M.: Mechanical Engineering, 1987. - 272 p.: Ill., Page 86, Fig. 5.7], consists in reducing the transverse dimensions of the engine, decreasing the aerodynamic drag of the rocket, increasing the total thrust impulse, eliminating the thermal effect on the rear half-hull, reducing the eccentricity of the thrust, reducing the weight, simplifying the design and simplifying the attachment of the semi-charge, and improving the technological design.

Claims (7)

1. A rocket engine of solid fuel containing two half-bodies - front and rear, equipped with front and rear half-shells of end combustion, the open ends of which are facing each other, a nozzle block and an ignitor, gas-connected with the half-shells, characterized in that the nozzle block is made in the form of one the central nozzle, gas-connected with the open ends of the half-charges by a flow pipe passed through the rear half-charge, and the rear half-charge is separated from the flow pipe, which passes inside the channel made in the rear luzaryad, and the surface of the channel is covered with a reservation, while the Central nozzle is mounted on a mounting flange made on the rear half-housing. 2. A solid fuel rocket engine according to claim 1, characterized in that a flow tube is passed through the front half charge and the front half housing with the front half charge and the rear half housing with the rear half charge are interchangeable. 3. The solid fuel rocket engine according to claim 1, characterized in that the igniter is located inside the flow pipe on the cover mounted on the mounting flange. 4. The solid fuel rocket engine according to claim 1, characterized in that the flow tube is attached to the half-shell through a process connector. 5. The solid fuel rocket engine according to claim 1, characterized in that a gap is made between the rear half charge and the flow tube, and a release layer is placed in the gap between the reservation and the flow tube. 6. The solid fuel rocket engine according to claim 1, characterized in that the length of the flow tube is less than the length of the rear hemisphere channel. 7. The solid fuel rocket engine according to claim 1, characterized in that the thickness of the flow tube or armor is made variable, increasing towards the mounting flange.

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