RU2705369C1 - Direct-expansion gas-dynamic device - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: invention relates to muzzle devices. Said gas-dynamic device is arranged coaxially with barrel and covers holes in barrel muzzle. It comprises body with side openings and baffle faces, body attachment device on barrel, vertical lengthwise walls and ribs. Gas flow is arranged so that it advances projectile and is directed to baffle faces without intermediate dispersion.

EFFECT: reduction of gas pressure at the device outlet, exclusion of negative effect of gases on the shell, increase of the device pulling force.

1 cl, 15 dwg

Description

The invention relates to the field of small arms and cannon armament and can be used to reduce the recoil force of powder gases during firing, and to reduce their negative impact on combat crew during the aftereffect.

Increasing the power of small arms and cannons leads to a significant increase in recoil force. One of the tools to reduce it are the barrel-type gas-dynamic devices. In this case, the main negative consequence of the use of such devices is the overpressure of the shock wave that they form, which can exceed the values established by medical standards.

There are designs of barreled gas-dynamic devices that provide dispersion of part of the flow of powder gases through channels of various shapes in their bodies during the passage of the projectile and after it, for example, the barrel-mounted gas-dynamic device of a 105-mm gun of the B1 Centauro tank fighter (Fig. 1).

A known design of a barrel-mounted gas-dynamic device of a 120-mm tank gun ХМ360 [1], containing (Fig. 2) a barrel 1 with holes 2 along its generators and representing a muzzle brake, covered by the body 3 along the entire length of the brake with windows 4 for the passage of powder gases and chipping faces 5. The housing 3 is coaxially attached to the barrel 1 by position fixation devices 6 and 7 to exclude its axial movement along the barrel. A positive property of the design is the preservation of the conditions of the projectile in its cavity, which is part of the barrel. The main disadvantage of this design is the lack of control of the structure of the flow of powder gases during firing in order to form the desired properties of the muzzle brake [2, 3]. The gas flow energy is dissipated through the openings 2 in the barrel 1 and the subsequent action of the gases weakened in this way with the baffle faces 5 of the housing 3 is made. The consequence of the adopted scheme is the fundamental impossibility of obtaining a high pulling force of the device during firing, which is due to the deliberate separation of the process of interaction of gases with the surfaces of the structure into the sequence of subprocesses in space and time, by artificial attenuation of the energy of gases due to their throttling through openings 2 in the trunk barrel 1.

The aim of the invention is to increase the impulse of the pulling force of the powder gases by eliminating the separation of the process of their interaction with the surfaces of the structure in space and time by organizing high-speed flows and significantly increasing the time it takes to directly impact the device faces when the projectile moves in the device cavity and after it leaves.

This goal is achieved by the following changes in the design of the prototype.

1. In the muzzle of the barrel (Fig. 3) at a distance of 0.90d from the muzzle end, two longitudinal holes 2 are made 3.65d long and have an opening angle of 104 ° from the top and bottom. The holes 2 are symmetrical with respect to the vertical and horizontal planes passing through the geometric axis of the bore. At the ends of the holes 2 far from the muzzle end (Fig. 3), internal chamfers with an angle of 20 ° are made. Walls a and b provide guidance of the projectile in the cavity of the device.

2. Housing 3 (Fig. 4) contains a cylindrical part A for placement on the outer surface of the barrel, a conical part B for the initial formation of consolidated flows of powder gases, a profile part C for organizing the movement of flows of powder gases with two vertical longitudinal walls c and e (Fig. .5), symmetrical with respect to the vertical and horizontal planes passing through the geometric axis of the bore and the distance between the walls equal to the caliber d of the gun, the upper and lower arcuate walls ƒ and g with the inner they radius 0.90d, part D with side windows 4 for the flow of propellant gases and baffle edges 5 for controlling the process in conjunction with the expiration tidal 8. The length of the window 4 is 1.20d, height 0.35d. The bump faces are vertical and deflected relative to the direction of the shot by 110 ° (Fig. 6). A cylindrical tide 10 is made in the front wall 9 of the width 1.10d of the housing 3 to support the outer surface of the barrel 1 in its muzzle. The joint width of the baffle faces 5 and the front wall 9 in the projection onto a vertical plane perpendicular to the axis of the bore is 2.50d. To increase the rigidity of the tides 8 on the outer surface of the profile part D (Fig. 4) longitudinal ribs 11 are made, connected to the transverse ribs 12, fastening the upper and lower tides 8. Elements 8, 11, 12 form windows 13 and 14 for the release of powder gases from cavity of the housing 3. All components of the housing 3 represent it as one part. Windows 13 and 14 are symmetrical with respect to the horizontal plane passing through the axis of the bore. Window 14 is 1.44d long and 0.77d high. The wall thickness of the body is determined by the conditions of its strength when fired.

3. The locking devices 6 and 7 (Fig. 7) are attached by a detachable connection to the barrel 1 and prevent axial movement of the housing 3 relative to it.

The operation of the device.

When the projectile (Fig. 8) passes through the longitudinal openings 2 of the barrel 1, a gap is formed between the shell of the projectile and the inner surface of the transition region of the housing, into which powder gases flow at a high speed, ahead of the projectile. Next, the gases act on the front wall 9 of the housing 3, exit through the windows 4 and 14, acting on the fenders 5 (Fig. 9). The initial deformation of the shape of the gas flow and the geometric characteristics of the flow channels ensure the maintenance of the flow structure with a destroyed central core during the movement of the projectile in the cavity of the device and in the aftereffect. Oncoming movement of gases at the exit from the windows 4 and the windows 14 of the housing 3 provides a reduction in the energy of the muzzle shock wave. The bulk of the gas flows through the windows 14, a substantially smaller part through the windows 13 of the housing 3. The high velocity of the gas flows in the muzzle region forms the structure of the medium flow, in which the main energy of the gases is carried out not towards the location of the gun crew.

The device used as a prototype has an efficiency (about 40%), which is clearly insufficient for modern field tools. Therefore, the assessment of the capabilities of the claimed design was carried out for a ballistic process similar to the 2A65 gun, the muzzle brake efficiency of which is about 63%. Modeling of the functioning of the claimed design was carried out on a full-scale three-dimensional model [3, 4, 5]. The field of study of the flow was limited by a parallelepiped with dimensions of 2000 × 2000 × 800 mm. The boundary conditions of the inlet flow corresponded to the data of a 152 mm 2A65 howitzer for a full charge and a high explosive fragmentation shell OF425. The values of the pulling forces in the direction of the shot for the prototype and model of the claimed invention are shown in FIG. 10. The ratio of the maximum value of the pulling force of the model to the maximum value of the pulling force of the prototype is 1.4, the ratio of the average values of the pulling forces is 2.94, the ratio of the pulses of the pulling forces is 3.13. The data are reduced to a limited simulation time range T = 0.003 s. By this time, the functioning of the prototype muzzle brake is almost complete.

The properties of the gas flow were recorded by sensors located in the horizontal plane of symmetry of the parallelepiped (Fig. 11). The nature of the pressure changes at the registration points for the prototype and model is shown in FIG. 12. Registration data indicate that the organization of the oncoming gas movement helps to reduce excess pressure. The nature of the gas pressure distribution on the inner surfaces of the flow channels of the device is shown in FIG. 13.

The geometric characteristics of the model of the invention (Fig. 14A) are within the geometrical characteristics of the muzzle brake of the gun 2A65 (Fig. 14B).

The components of the inventive design of a barrel gas-dynamic device are shown in FIG. fifteen.

According to the simulation results of the shot process, we can conclude that the stated goals are realized in the proposed design of the barrel gas-dynamic device. Wherein:

- increases the time spent by gases in the chambers of the device due to the special organization of the channels of their leading projectile flow above and below the moving projectile, which leads to the destruction of the central core of the gas stream during the movement of the projectile in the cavity of the device, and the formation of wave compression flow, eliminating the restoration of the integrity of the central core of the stream gases in the aftereffect;

- increases the pulling force of the device due to the supply of gases to the front wall and the baffle faces of the device without intermediate dispersion;

- an increase in the impulse of the pulling force of the powder gases;

- reduced gas pressure at the outlet of the device due to the loss of their energy in the oncoming interaction;

- eliminated the negative effect of gases on the projectile due to its constant contact with the guide walls of the barrel.

Sources.

1.120-MM TANK FOR THE FUTURE MCS. http://otvaga2004.ru.

2. Sergeev M.M. Theory and calculation of muzzle brakes. - M.: State Publishing House of the Defense Industry, 1939. - 140 p.

3. Orlov Yu.V., Larman E.K., Malikov V.G. Arrangement and design of artillery barrels. M .: Mechanical Engineering, 1976 .-- 432 p.

4. Alamovsky, A.A. SolidWorks 2007/2008. Computer modeling in engineering practice / A.A. Alamovsky. Teaching aid. - SPb .: BHV-Petersburg, 2008 .-- 1040 s.

5. Cherchinyani K. Theory and applications of the Boltzmann equation. M .: Mir, 1978.- 496 p.

6. Krivovichev G.V. On the calculation of viscous fluid flows by the method of lattice Boltzmann equations. Computer Research and Modeling, 2013 vol. 5 No. 2 p. 165-178.

Claims (1)

A barrel gas-dynamic device containing a barrel with holes in the body of the muzzle part of the barrel, placed coaxially with the barrel and overlapping the holes in its muzzle part of the body with side windows and fender faces, device for fixing the body on the barrel, characterized in that the holes are longitudinal in shape at a distance of 0.9 d from the muzzle cut at the top and bottom with a length of 3.65d and an opening angle of 104 ° in plan, the holes are symmetrical with respect to the vertical and horizontal planes passing through the geometric axis of the bore , on the ends of the holes farthest from the muzzle end, internal chamfers with an angle of 20 ° are made, the body contains a cylindrical part for supporting the outer surface of the barrel, a conical part for the initial formation of consolidated flows of powder gases, a profile part for organizing the movement of powder gas flows, limited by two vertical longitudinal walls symmetrical with respect to the vertical and horizontal planes passing through the geometrical axis of the bore and a distance between walls equal to cal the gun d, the upper and lower arched walls with an inner radius of 0.9d, the front wall of the casing with a width of 1.1d, a part for the removal of powder gases with side windows in the vertical walls of the profile part with a length of 1.2d and a height of 0.35d, starting from the inner surface of the front wall of the casing , fenders with vertical faces, which are a continuation of the front wall and deviated relative to the direction of the shot by 110 °, the joint width of fenders and the front wall of the body in projection on a vertical plane perpendicular to and the bore, is 2.5d, arcuate tides overlapping the side windows of the profile part, with side windows 1.44d and 0.77d high made in them, the windows in the tides are symmetrical with respect to the horizontal plane passing through the axis of the bore channel on the outer surface of the profile part the body symmetrically to the horizontal plane passing through the axis of the bore, longitudinal ribs are made, connected to the tides so that they form the rear windows for the exit of powder gases from the body cavity, in the front wall Pusa cylindrical tide configured for support on an outer surface of the barrel at its muzzle, the housing fixing device mounted on the trunk of a releasable connection with the trunk in the front and rear of the housing.

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