RU2428581C1 - Testing method and device of solid-propellant rocket engine - Google Patents

Abstract

FIELD: engines and pumps. ^ SUBSTANCE: testing method of solid-propellant rocket engine involves installation of self-contained engine on the base so that it is borne against rigid wall, starting, measurement of operating parameters and determination of operability of engine housing. After engine starting the partial or full shutoff of critical section of its nozzle is performed, which leads to destruction of engine housing. During measurements there recorded are pressure values of fuel combustion products in engine chamber prior to full or partial shutoff of critical section of nozzle and values of the pressure at which the housing was destructed; and as per the above values the safety factor of engine housing is determined. Testing device of rocket engine includes the base, rigid wall and blind telescopic shaft. The latter is installed onto the base coaxially to rocket engine with possibility of extension of movement of movable part of the shaft into rocket engine nozzle. On front end of movable part of shaft there fixed is plug; propellant charge is arranged in its cavity on the side of closed end, and pyrocartridge is installed on closed end. ^ EFFECT: inventions allow improving accuracy of determination of safety factor of rocket engine. ^ 2 cl, 1 dwg

Description

The invention relates to tests and testing equipment. The primary field of application is testing solid propellant rocket engines.

Solid fuel rocket engines in the process of creation and mass production are subjected to various tests, the purpose of which is to confirm their operability in the conditions of use.

A known method and device for hydraulic testing of a rocket engine of solid fuel (see the book by V.I. Feodosiev and G. B. Sinyarev “Introduction to rocket technology”, Oborongiz, 1960, p. 487), during which an unloaded engine (i.e. without fuel) with a plug instead of a nozzle, they are loaded with internal fluid pressure. During hydrotesting, the pressure is gradually increased to a level that exceeds the maximum operating pressure by a predetermined amount, which is maintained for a certain time. After that, the pressure is vented and the engine is faulted.

The disadvantage of the method and device for hydraulic testing of a solid fuel rocket engine for strength is the mismatch between the loading rate of the tested engine block being realized during their implementation and the actual rate of its loading, as well as the lack of heating of the engine block that occurs during rocket fuel combustion and reduces its mechanical characteristics.

Closest to the proposed technical solution are selected as a prototype method and device for fire bench tests (AIS) of solid propellant rocket engines (see ibid.). In such tests, an equipped engine (i.e., with fuel) is mounted on a bench containing a rigid wall base. At the same time, its frontal part is abutted against a rigid wall through a force sensor (traction sensor). The engine is started from a ground source of electric current. In the process of its operation, the pressure of the combustion products of the fuel in its chamber, the draft and other parameters are measured.

According to the results of the OSI, the compliance of the measured intra-ballistic characteristics, primarily the pressure in the chamber and the thrust, with the requirements of the documentation, as well as the operability of the engine housing under mechanical and thermal effects of fuel combustion products on it, is checked.

The disadvantage of the method and device for firing bench tests of a rocket engine of solid fuel is the inability to determine the safety margin of the engine housing from their results.

The technical problem to be solved is the creation of a method and device for testing a rocket engine of solid fuel in conditions as close as possible to the conditions of its application.

The expected technical result when applying the inventive method and device for testing is to determine the real safety factor of the body of a rocket engine of solid fuel, which subsequently improves the reliability of the engine.

The technical result is achieved by testing a rocket engine of solid fuel according to the claimed method, which includes installing an equipped engine on a base with the emphasis of its frontal part on a rigid wall, starting, measuring engine operation parameters and determining with their use the operability of the engine housing during mechanical and thermal effects of combustion products fuel. In contrast to the prototype, at a given point in time after starting the engine, including immediately before the end of the combustion of solid fuel, the critical section of its nozzle is partially or completely blocked, which leads to an increase in pressure in the chamber and destruction of the casing, while the pressure values of the products of combustion of fuel are fixed in the engine chamber before full or partial overlapping of the critical section of the nozzle and the pressure at which the destruction of the housing occurred. These values determine the safety factor of the solid rocket engine housing.

The technical result is achieved by implementing the inventive method on the inventive device for testing a rocket engine of solid fuel, containing a base and a rigid wall to abut the frontal part of the engine. In contrast to the prototype, the device is additionally equipped with a blind telescopic barrel mounted on the base coaxially to the rocket engine with the possibility of extending its movable part into the engine nozzle, and at the front end of the movable part of the barrel a profiled plug is installed to block the nozzle, a powder charge is placed in its cavity, and on the closed end of the fixed part of the barrel is equipped with a squib.

Equipping the testing device with a blind telescopic barrel mounted on the base coaxial to the rocket engine with the possibility of extending its movable part with a plug into the nozzle of the rocket engine allows you to completely or partially overlap the critical section of the nozzle of the rocket engine. Full or partial overlapping of the critical cross section of the nozzle of the rocket engine after it starts allows you to increase the pressure in the engine chamber at a predetermined point in time, including immediately before the end of fuel combustion, to a value at which its body in the weakest point is destroyed. The values of the pressure at which the destruction occurred and the pressure recorded at the time point preceding the nozzle shut-off determine the value of the safety factor of the engine housing, based on which the health of the housing is judged by the mechanical and thermal effects of fuel combustion products.

The invention is illustrated by a figure, which schematically shows a device for testing a rocket engine.

A device for testing a rocket engine of solid fuel 1 contains a rigid wall 2, a rail base 3 for installation on it using sliding supports (shoes) 4 of the rocket engine. A deaf telescopic barrel 5 is mounted on a rail base 3 using a fixed support 6 coaxial to a solid fuel rocket engine 1 with the possibility of sliding its movable part 7 into the nozzle 8. At the front end of the movable part 7 of the barrel 5, a profiled plug 9 is fixed to block the nozzle in its cavity a powder charge 10 is placed, and on the closed end of the fixed part of the barrel 5 a squib 11 is mounted.

The inventive method of testing a rocket engine of solid fuel is carried out when the device is operated as follows.

The solid fuel solid fuel rocket engine 1 is mounted on a rail base 3 with the frontal part resting on the rigid wall 2. The telescopic barrel 5 is mounted on the base 3 coaxially with the rocket engine 1 with the possibility of sliding the movable part 7 into the nozzle 8. The rocket engine 1. is launched. time supply voltage to the igniter 11, thereby igniting the powder charge 10, the combustion products of which fill the cavity of the telescopic barrel 5 and push its moving part 7 towards the nozzle 8, overcoming the impact the pressure of the gas jet of the working engine 1. The plug 9 fixed on the front end of the movable part 7 of the barrel 5, sliding into the nozzle 8, partially or completely blocks its critical section, as a result of which the pressure in the engine 1 increases until the engine casing is destroyed in the weakest place. During the operation of the engine 1, the pressure values of the products of fuel combustion in its chamber are measured at the time moment preceding the overlap (partial or full) of the critical section of the nozzle, including immediately before the end of the combustion of the fuel, and the pressure at which the engine casing was destroyed. The safety factor of the engine casing is determined from these values, based on which the working capacity of the solid rocket engine casing is judged by the mechanical and thermal effects of fuel combustion products.

Thus, the inventive method and device for testing a solid propellant rocket engine allows you to determine the actual safety factor of the engine housing in conditions as close as possible to the conditions of its use.

Claims (2)

1. A method of testing a rocket engine of solid fuel, including installing an equipped engine on a base with the emphasis of its frontal part on a rigid wall, starting, measuring operation parameters and determining, with their use, the operability of the engine housing during mechanical and thermal effects of fuel combustion products, characterized in that at a given point in time after starting the engine, a partial or complete overlap of the critical section of its nozzle is produced, leading to the destruction of the engine casing, while essays measurements recorded values of pressure of the combustion products in the chamber before the complete or partial overlap of the nozzle throat and the pressure at which failure occurred housing which define the safety factor of the motor housing. 2. A device for testing a rocket engine containing a base, a rigid wall for abutting the frontal part of the engine, characterized in that it is additionally equipped with a blind telescopic barrel mounted on the base coaxially to the rocket engine with the possibility of sliding the movable part of the barrel into the nozzle of the rocket engine, and the front end of the movable part of the barrel is fixed with a plug for the nozzle, a powder charge is placed in its cavity from the closed end, and a squib is mounted on the closed end.