RU2378524C1 - Engine of reactive weapon - Google Patents

Abstract

FIELD: arms.

SUBSTANCE: invention is related to the field of military equipment, namely to jet engines with low time of operation for weapons intended for firing from marine grenade launching systems. Engine of reactive weapon comprises combustion engine with tubular charge of solid propellant installed in it and rested upon diaphragm, which is equipped with holes, and nozzle. Centers of diaphragm holes are coordinated according to law of equilateral triangle, side of which makes at least 1.07 of hole diametre. Ratio of average diametre of powder tube to diametre of diaphragm hole is within the limits of 1.6-1.9.

EFFECT: invention makes it possible to provide for uniform strength of jet engine diaphragm, and also to reduce exhaust of unburnt remains of powder tubes with provision of ratios of areas of diaphragm cross section and critical section of nozzle of at least 1,3.

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Description

The invention relates to the field of military equipment, in particular to jet engines with a short operating time (not more than 0.02 s) for ammunition intended for firing from grenade launcher systems placed on any warships afloat.

Difficulties in the design and development of engines with a short operating time (not more than 0.02 s), equipped with quick-burning formulations of tubular powders, are exacerbated by insufficient study of the physical picture of intense heat-stressed processes occurring in these types of engines. Therefore, one of the important factors is the creation of an optimal equal-strength diaphragm, providing a ratio of the area of its openings to the area of the critical section of the nozzle of at least 1.3 and excluding the discharge of unburned remains of powder tubes beyond the nozzle exit.

A jet engine is known (French patent No. 1200002 - prototype), which shows various designs of diaphragms that provide centering of the tubular powder charge in the engine chamber and have enlarged openings for the entry of combustion products into the inlet of the nozzle.

The disadvantages of this design of a jet engine include:

- lack of diaphragm equal strength, which can lead to unpredictable local destruction of jumpers between holes;

- the lack of stability of the ballistic characteristics of the engine due to the possible release of unburned remains of the powder tubes over the nozzle exit.

The task of the invention is to improve the ballistic characteristics of the engine of a jet weapon.

The technical result consists in ensuring the uniformity of the diaphragm of the engine and reducing the emission of unburned residues of the powder tubes while ensuring the ratio of the passage area of the diaphragm and the critical nozzle section of at least 1.3.

The technical result is achieved in that the rocket-propelled munition engine contains a combustion chamber with a tubular charge of solid fuel placed therein, supported by a diaphragm equipped with holes, a nozzle, while the centers of the holes of the diaphragm are coordinated according to the law of an equilateral triangle, the side of which is at least 1.07 in diameter holes, and the ratio of the average diameter of the powder tube to the diameter of the hole of the diaphragm is in the range of 1.6-1.9.

Significant test statistics of engines equipped with a fast-burning multi-tube powder charge confirm that the pressure dispersion of powder gases in the engine chamber increases sharply with a decrease (less than 1.3) of the ratio of the passage orifice cross section and the nozzle critical section, and material softening in the diaphragm bridges and discharge of unburned remains of powder tubes.

The implementation of the diaphragm, in which the holes are coordinated according to the law of an equilateral triangle with the ratio of the side to the diameter of the hole at least 1.07, allows the diaphragm to be equally stable while maintaining the ratio of the area of the aperture of the diaphragm and the critical section of the nozzle at least 1.3, and therefore, to eliminate local fractures jumpers between the holes, the ejection of fragments of the diaphragm and unburned remains of the powder tubes, which ultimately significantly improves the ballistic characteristics of the motor body (the dispersion in pressure in the engine chamber and in the initial velocity of the ammunition is reduced).

It is known that tubular quick-burning powder charges are subject to erosive combustion (the burning rate of the powder tubes in the nozzle part of the chamber is higher than the burning speed of the powder tubes in the bottom of the chamber), which can lead to a break in the powder tube during combustion and removal of the pre-nozzle part from the chamber through the hole in the diaphragm powder tube, which significantly impairs the ballistic characteristics of the engine.

The use of a tubular quick-burning powder charge for equipping a jet munition engine with a ratio of the average diameter of the powder tube to the diameter of the diaphragm hole in the range of 1.6-1.9 allows to increase the fill factor and the completeness of combustion of the powder charge in the engine chamber.

When this ratio decreases, due to the difference in the burning speed of the powder tubes in the pre-nozzle and bottom parts of the combustion chamber, the emission of unburned remains of the powder tubes from the chamber increases (which sharply increases the pressure spread in the engine chamber).

With an increase in this ratio, the coefficient of use of the effective volume of the chamber deteriorates, and ultimately, the ballistic characteristics of the engine deteriorate significantly (the total impulse of engine thrust decreases).

Figure 1 shows a General view of the engine of a jet weapon.

Figure 2 shows on an enlarged scale a fragment of the diaphragm.

The engine of the rocket ammunition consists of a chamber 1, a tubular powder charge 2, a diaphragm 3, an igniter 4, a nozzle 5, on the surface of which a stabilizer 6 is mounted, an electric igniter 7.

The aperture openings are coordinated according to the law of an equilateral triangle 8.

The operation of the rocket ammunition engine is as follows.

When applying an electric pulse to the electric igniter 7, its igniter composition is activated, which ignites the ignitor 4. The flame beam from the igniter 4 is transmitted to the tube powder charge 2 and ignites it. When a certain gas pressure is reached in the engine chamber 1, the gaseous products of fuel decomposition flow out of the chamber through the holes in the diaphragm 3 and the critical section of the nozzle 5. Under the influence of the engine traction, the ammunition starts moving in the barrel channel of the grenade launcher system.

The implementation of the proposed technical solutions in the design of the rocket-propelled munition engine, confirmed by the results of land and sea tests, allows to improve the ballistic characteristics of the engine by ensuring the diaphragm is equally stable and the combustion of the powder charge in the engine chamber is complete.

Claims (1)

A jet munition engine containing a combustion chamber with a tubular charge of solid fuel placed in it, supported on a diaphragm equipped with holes, a nozzle characterized in that the centers of the holes of the diaphragm are coordinated according to the law of an equilateral triangle, the side of which is at least 1.07 of the diameter of the hole and the ratio of the average diameter of the powder tube to the diameter of the aperture is in the range of 1.6-1.9.

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