RU2133369C1 - Solid-propellant rocket engine - Google Patents

Abstract

FIELD: rocketry. SUBSTANCE: engine includes powder charge whose channel is widened on side of front neck; start ands ignition device located in it at spaced relation has front head and cylindrical-spherical casing inside which support, igniter and perforated progressive-burning grain are located; support is made in form of cruciform bush with gas ducts changing into central critical orifice. head and casing of start and ignition device are provided with heat shields; electric igniter located in head opposite igniter is connected with start and ignition device by means of gas duct. Smooth heating accompanied by complete ignition of entire powder charge by jet of gas escaping from start and ignition device enhances operational reliability of rocket engine, both at positive and negative temperatures. EFFECT: enhanced efficiency of rocket engine. 2 dwg

Description

 The present invention relates to rocket science and takes into account the increasing requirements to improve the perfection of the design of rocket engines and the reliability of their work.

 There is a rocket engine of solid fuel [1], containing a combustion chamber with a nozzle socket and a support made of composite material, a fixed charge of solid fuel with an axial channel placed in it, an igniter mounted on the front bottom fixed in a metal frame, characterized in that it is equipped a spring-loaded piston supported by a charge of solid fuel with a central bore, and in the igniter housing a blind axial channel is made in which the piston is located, while the nozzle nozzle is provided with metal an elastic funnel with a spring tail on the side of the combustion chamber, and between the funnel and the nozzle funnel there is an elastic gasket, the connection of the front bottom and the metal frame is made in the form of helical ring winding laid between the teeth with glass fiber, and the teeth are made in a pyramidal shape, the sides of the bases of which are angled to the corner of the winding glass. However, this engine design in relation to engines with a powder charge firmly fixed to the engine case is unreliable due to imperfections in the ignition device, namely, a thin-walled igniter case can be destroyed until the entire pyrotechnic composition is completely ignited, then part of the composition will be ejected from the case, which will lead to an increase in time delays in the ignition of the powder charge and the instability of the engine reaching the calculated mode, or to its attenuation - especially at minus temperature, because the charge does not have enough time to warm up, which is unacceptable. An increase in the igniter sample will lead to an increase in pressure inside the engine, which will lead to breakage (cracking) of the channel of the powder charge firmly bonded to the engine body, which is unacceptable.

 There is a solid-propellant rocket engine [2] Space Shuttle with a powder charge firmly bonded to the engine body and a trigger device, consisting of a body with external and internal thermal insulation with a central nozzle and liner, a large powder charge of the trigger device, ignition of which is carried out from a small trigger device installed in the engine cover. This design of a rocket engine with such a firing device has a high degree of reliability of ignition of the main powder charge of the engine, which takes place in three stages and is therefore used in large-sized ballistic missile engines, where the engine start time is short compared to the flight time of a ballistic missile and is unacceptable for anti-aircraft missiles , where the flight time is short up to 3 - 3.5 seconds, and the time to ignite the powder charge of the engine is tenths of a second. Therefore, the objective of the proposed invention is to eliminate the above disadvantages, namely the use of a starting device in rocket engines of anti-aircraft missiles, which provides a high degree of reliability of the engine at both positive and negative temperatures, due to uniform heating and tracking of the complete ignition of the powder charge by a stream of exhaust gas from the ignition device.

 This goal is achieved by the fact that in a solid propellant rocket engine the powder charge from the front neck has a channel broadening in which there is a gap ignition device consisting of a front bottom and a cylinder-spherical case attached to it, inside which there is a support, an igniter and a channel a powder checker accompanying combustion, while the support is made in the form of a cross-shaped sleeve with gas ducts passing into the central critical hole, and the bottom and core the start of the starting device is made with heat shields, and in the bottom opposite the igniter there is an electric igniter connected to the internal cavity of the starting device with a gas channel.

 The essence of the invention lies in the fact that the ignition device, without collapsing, allows for a rather long time to form a stream of hot powder gas emanating from the critical hole, thereby providing heating of the powder charge of the engine until it is completely ignited, at a relatively low pressure in the ignition device, due to the installation of a channel gun powder accompanying combustion.

 In FIG. 1, 2, 3 shows the proposed design of a rocket engine of solid fuel, where 1 is the engine housing of a composite engine with a nozzle; 2 - powder charge firmly bonded to the housing; 3 - a front mouth; 4 - firing device (Fig. 2); 5 - broadening of the channel of the powder charge; 6 - front bottom; 7 - cylinder-spherical body; 8 - cruciform support (Fig. 3); 9 - igniter; 10 - channel powder bomb accompanying combustion; 11 - gas channels of the support; 12 - a central critical hole; 13 - heat shield of the front bottom; 14 - heat shield of the housing; 15 - electric igniter; 16 - gas channel; 17 - the internal cavity of the firing device.

 The assembly and operation of the rocket engine of solid fuel is carried out as follows: first they assemble (equip) a start-ignition device 4, into the cylinder-spherical body 7 of which, with a heat shield 14 and a cross-shaped support 8, an igniter 9 is installed in a special seat of the support, then a channel powder checker is put on the support combustion 10, while the igniter 9 is located inside the channel of the powder checkers 10. The front bottom 6 is screwed onto the cylindrical spherical body 7 by thread, while The protective screen 13 of the bottom is located in the inner cavity 17 of the trigger device 4.

 The assembled ignition device 4 is installed in the front neck 3 of the engine casing 1, in broadening of the channel 5 of the powder charge 2, which is firmly bonded to the casing. After checking the engine for leaks, an electric igniter 15 is installed outside the gas front channel 17. The engine is mounted on a test bench. After applying voltage to the contacts of the electric igniter 15, its initiating composition ignites, the igniter 9 ignites from the generated flame through the gas duct 16, and the channel powder gun 10 of accompanying combustion ignites from the igniter gases. The powder gases from the checker, creating a calculated pressure inside the ignition device, rush through the gas ducts of the support 11, forming a jet stream through the central critical hole 12 into the engine, thereby warming up the powder charge of the engine and accompanying it to ignition until completely ignited, after which the engine goes to set operation mode.

 The powder charge from the front throat of the engine has a channel broadening in diameter, the channel broadening is obtained from the filling needle when pouring the mixed powder charge of solid fuel and serves to install a trigger device in it.

The cylindrical body of the ignition device is made of steel with an external heat shield, which allows it to withstand the thermal and power loads that occur in the engine until the end of the work without breaking. Inside the case does not have thermal protection due to the relatively short operating time of the powder checker accompanying combustion, in relation to the main charge. The aluminum front bottom of the ignition device inside the housing is made with a heat shield that protects it from burnout, because aluminum is more susceptible to temperature effects than a steel case, in addition, the front bottom of the ignition device is also the front bottom of the rocket engine, which burnout is unacceptable. In order to improve the launch of the ignition device, the igniter is installed inside the channel of the powder block, which has a calculated combustion surface. A powder checker accompanies (supports) the combustion of the main powder charge until the engine reaches full rated operation. The critical hole of the support is designed in such a way that it provides gas flow (jet formation) at a minimum design pressure inside the ROM. The use of a firing device of this design when starting a cold engine (up to -50 ^o C) eliminates its attenuation in relation to the analogue.

Sources of information
1. Patent of Russia N 2053401, publ. BI N 3 (part 2) from 01/27/96, MKI F 02 K 9/04.

 2. Textbook for universities "Design and design of solid propellant rocket engines", I. Kh. Fakhrutdinov, A.V. Kotelnikov. M .: Engineering, 1987, p. 12-16, Fig. 1.7, 1.8, p. 213, fig. 9.9.

Claims (1)

 A solid propellant rocket engine, comprising a composite housing with a nozzle and a front neck, a channel combustion powder charge and a firing device firmly bonded to the housing, characterized in that the powder charge on the front neck side has a channel broadening in which a firing device is placed with a gap , consisting of a front bottom and a cylinder-spherical body attached to it on a thread, inside of which there is a support, an igniter and a channel powder canister and accompanying combustion, the support is formed as a cruciform bushing gazovodnymi channels passing into the central critical orifice and the bottom and body puskozazhigatelnogo device configured to heat shields, and a bottom opposite the igniter disposed electric igniter connected to an internal cavity puskozazhigatelnogo device gazovodnym channel.

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