RU2817285C1 - Method of shooting and muzzle brake - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method of firing, in which energy of powder gases flows is concentrated by reducing the cross-sectional area of their flow channels, separation of powder gases flows into external and internal ones with screening of internal flow by external ones, creating a high pressure zone in the area of the front wall of the brake, area of vertical expansion of near-wall flow is limited, gas flow core is destroyed by means of screening of central channel with powder gases after projectile exit from cavity of diesel fuel to maintain high pressure in area of front wall of brake during the whole period of aftereffect. Muzzle brake comprises body with annular, conical and cylindrical parts, bosses with openings made in them. Side windows made in the bosses of the cylindrical part of the brake body are rectangular. Beginning of the tides coincides with the plane of the end of the conical part of the body and the beginning of the cylindrical part. Front wall of brake is connected to walls of cylindrical part of housing with rounding. Inner diameter of the annular part and the minimum inner diameter on the conical and cylindrical parts of the body are equal to the calibre of the barrel d in the form of two arcs with an angular size of 90° and symmetrical relative to central vertical and horizontal planes of the brake body.

EFFECT: increased pulse of pulling force of muzzle brake, reduced excess pressure of powder gases in direction of combat crew.

2 cl, 25 dwg

Description

An important element of modern barreled weapons is the muzzle brake (MT), which, along with other devices, provides a significant reduction in the force effect of powder gases (PG) when fired on weapon elements.

The functioning of diesel generator structures is based on the method of dissipating GHGs, the essence of which is to divert part of their flow through windows in the diesel engine housing. “At the same time, the flow of gases in the direction of the channel axis decreases, which reduces the reactive force in the direction of movement of the barrel, and due to the rotation of the gas stream in the muzzle brake channels or due to the impact of the central jet on the front wall of the brake, a reactive force appears acting in the direction shaped like rollback, and reducing the rollback energy" {1, p. 386]. The dissipation method ensures the force action of the SG by a weakened peripheral flow, briefly amplified by the energy potential of the central core while the bottom of the projectile passes through the areas of outlet windows in the DT body. At the same time, a quantitative change in the design parameters of the diesel engine does not provide an increase in the impulse of its pulling force, which goes beyond the boundaries of the established relationships between the functioning process and the design of the diesel engine [2, 3, 4].

There are known barrel artillery guns (family of 2B16 type guns), the design of which uses diesel fuel. The peculiarities of the functioning of diesel fuel in such tools are determined by the following factors:

- the outflow of powder gases, from the moment of ignition of the propellant charge until the end of the period of aftereffect of the powder gases on the barrel;

- low ballistics of the propellant charge, excluding a significant increase in the efficiency of diesel engines of the classical design;

- flow of gases around the projectile in the cavity of the diesel engine, which leads to an increase in the force action of the gas on the projectile compared to the diesel engine, which has a diaphragm that cuts off the side flow of gases in the internal cavity of the body;

- relatively short barrel length, which leads to a limitation in the effectiveness of diesel engines due to medical requirements for the amount of excess pressure of the PG on. gun crew locations;

- restrictions on the weight of diesel engines due to restrictions on the weight of the entire gun.

The design of a muzzle brake is known, [5], containing (Fig. 1) a body 1 with an annular part A, a conical part B and a cylindrical part C. In the cylindrical part C of the body 1 (Fig. 2) there are bosses 2 vertical side windows 3 rectangular forms with three vertical 4 and one horizontal 5 dividers. The bosses and windows are located symmetrically relative to the longitudinal vertical plane of the brake housing 1. On the outer surface of the housing 1 (Fig. 3) there are longitudinal stiffening ribs 6 at the top and bottom. On the inner surface of the housing 1 (Fig. 3) there are longitudinal stiffening ribs 7 in the upper and lower parts.

The process of functioning of such a diesel engine is implemented by the following operations (Fig. 4):

- flow around the PG projectile in the DT cavity from the moment the rear conical part of the projectile passes the muzzle end of the barrel until the moment this part of the projectile passes the front cut of the DT body;

- the impact of powder gases on the front wall of the muzzle brake, followed by their dispersion into the atmosphere through the side windows. In this case, a pulling force is created, which helps to reduce the force action of the steam generator on the sliding parts.

A certain advantage of the muzzle brake design is its compactness and low weight.

The main disadvantage of this design, due to the specifics of the functioning of the diesel engine, is the limited time of formation of the muzzle brake pulling force pulse, which is almost equal to the time of passage of the projectile through the cavity of the brake housing 1 (Fig. 5).

The purpose of the claimed invention is to increase the impulse of the pulling force of the muzzle brake, to reduce the excess pressure of powder gases in the direction of the combat crew.

To achieve this goal, a new method of increasing the pulling force of a diesel engine and a brake design that ensures the implementation of this method are proposed.

The method includes the following operations:

- concentration of the energy potential of GHG flows by reducing the cross-sectional area of their flow channels. An implemented version of concentrating gas flow channels is shown in Fig. 6. The guide part of the brake is made (Fig. 7) in the form of two arcs with an internal diameter equal to the caliber of the gun d, the angular size of the arcs k (Fig. 8) of the guide part of the body (sections B and C, Fig. 6) is equal to 90 degrees ( Fig. 8). Arcs k are placed vertically and symmetrically relative to the central vertical and central horizontal planes passing through the axis of the brake housing. The length c (Fig. 7) of the transition cone B is equal. 1.53d, the height a of the profile is equal to. 1.32d, profile width b is 2.25d. The length h (Fig. 9) of the cylindrical section C is 2.35d. The tides of the transition cone B and the cylindrical part C of the body 1, organized in this way, provide an increase in the gas flow rate and ejection of the area behind the muzzle of the barrel.

- separation of flows into external (first wall) and internal (Fig. 9, Fig. 10) in order to create a zone of high static pressure in the area of the front wall w of the diesel engine due to shielding of the internal SG flow by the external one. For this purpose, the cylindrical part C of the housing 1 contains side windows 10 (Fig. 9) of a rectangular shape. The height from windows 10 (Fig. 8, Fig. 9) is equal to 1.06d, the width f of window 10 (Fig. 9) is equal to 1.49d. The center of the window is located from the front end of the brake housing at a distance g equal to 1.16d. The corners of the side windows are rounded. The separating component is the front edge of the window 10 (Fig. 10). In addition, shielding the internal flow with the external one ensures a reduction in the excess pressure of the steam generator at the combat crew locations;

- limiting the area of vertical expansion of the wall flow in order to maintain the energy potential when exiting the cavity of the diesel engine. To do this, on the inner upper and lower horizontal surfaces of part C of the housing. 1, tides s are completed (Fig. 11). The beginning of the tides s coincides with the plane of the end of the conical part B and the beginning of the cylindrical part C. The total length b1 of the tide s (Fig. 12) is equal to 0.72d, the length b2 of the front part of the tides s is equal. 0.13d, radii R1 and R2 are 5.15d and 0.21d, respectively;

- destruction of the core of the PG flow in order to maintain a zone of high static pressure in the area of the front wall w of the diesel engine by shielding the central channel with powder gases after the projectile exits the cavity of the diesel engine. To do this, the front wall w DT (Fig. 13) is connected to the walls of the cylindrical part C of the housing 1 with a rounding R3 equal to 0.25d.

Implementation of the method and operation of the muzzle brake.

When the rear conical part of the projectile passes the beginning of section B, a gap is formed (Fig. 14, top view) between the projectile body and the inner surface of the tides in the transition area of the brake housing 1, into which powder gases enter at high speed, ahead of the movement of the projectile. The first operation is implemented - the concentration of gases flowing from the barrel into two streams. A zone of deep discharge of powder gases is formed towards the area of the muzzle of the barrel, which functions as such throughout the period of aftereffect of the gases on the barrel and helps prevent backfire when opening the bolt.

Next, the second operation is implemented - dividing the GHG flow into external and internal. Part of the gases closest to the side wall of the tides of the cylindrical part C of the housing 1 immediately flows through the windows 10 into the atmosphere (Fig. 15, Fig. 16). This part of the gas, after expiring into the atmosphere, serves as a protective screen that prevents the spread of the internal part of the gases towards the gun crew and helps reduce excess pressure at the places where it is located. For this part of the gases, a third operation is implemented - limiting the area of vertical expansion as an additional concentration of the external gas flow (Fig. 17, Fig. 18) in order to increase the efficiency of screening the internal flow. The internal part of the gas flow acts on the front wall w of housing 1 (Fig. 16), creating over time a zone of increased static pressure, after which it also flows through windows 10 into the atmosphere.

During the period of passage of the conical rear part of the projectile through the window of the front wall w of the DT housing 1 (Fig. 19) and further until the end of the aftereffect period, the fourth operation is implemented - the destruction of the core of the SG flow. The internal part of the gases in the flow channels, previously reflected from the projectile body before exiting into the atmosphere, now in counter motion due to the directional rounding R3 (Fig. 13) screens the central channel, which leads to the destruction of the core of the gas flow and ensures the formation of the pulling force of the diesel engine until the end of the period aftereffects.

The presence of guide arcs k (Fig. 8) increases the protection of the side surface of the projectile from the action of powder gases, reducing the likelihood of its damage in the aftereffect period.

The high speed of gases forms a structure of the flow of the medium in the muzzle region, in which the main energy of the flow is carried away not towards the location of the gun crew.

By assessing the capabilities [6, 7] of the invention in comparison with the method of dispersing powder gases and the design of the prototype [5] for an intra-ballistic process similar to a 2B16 gun with an OF49 projectile at full charge during the study period T = 0.008 s, the excess of the pulling force impulse was determined to be more than 5 once. Excess pressure of the muzzle shock wave was recorded during the entire time of the process under study at eight points (Fig. 20). Typical graphs of excess pressure functions are shown in Figures 21-24.

The initial deformation of the gas flow shape 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 period.

The geometric characteristics of the invention model are within the geometric characteristics of the prototype. The main components of the brake design are shown in Fig. 25.

Based on the results of modeling the firing process, we can conclude that the stated goals are achieved by the proposed method and the design that implements it.

Sources.

1. Serebryakov M.V. Internal ballistics of barrel systems and powder rockets. M.: Oborongiz, 1962. - 703 p.

2. Slukhotsky V.E. Questions of intermediate ballistics. / V.E. Slukhotsky. - M., L.: Publishing department. People's Commissariat of Military and Marine Affairs, 1934, - 72 p.

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

4. Orlov B.V. Construction and design of artillery gun barrels / B.V. Orlov, E.K. Larman, V.G. Malikov. - M.: Mechanical Engineering, 1976. - 432 p.

5. https://topwar.ru/1943 16-buksiruemoe-orudie-2b16-nona.-k.html.

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

7. Krivovichev G.V. On the calculation of viscous fluid flows using the lattice Boltzmann equation method. Computer research and modeling, 2013 vol. 5 No. 2 p. 165-178.

Claims (2)

1. A method of firing in which the gas flow rate in the direction of the channel axis is reduced, the gas jets are rotated in the muzzle brake channels and the central jet hits the front wall of the brake with the formation of a reactive force, characterized in that the energy potential of the powder gas flows is concentrated by reducing the cross-sectional area channels of their flow, separate the flow of powder gases into external and internal with shielding of the internal flow by the external, and create high pressure zones in the area of the front wall of the brake, limit the areas of vertical expansion of the wall gas flow to maintain their energy potential when exiting the brake cavity, destroy the core of the flow gases by shielding the central channel with powder gases after the projectile leaves the cavity of the diesel engine, and maintain high pressure in the area of the front wall of the brake throughout the entire aftereffect period. 2. A muzzle brake containing a body with annular, conical and cylindrical parts, bosses with windows made in them, characterized in that the internal diameter of the annular part and the minimum internal diameter on the conical and cylindrical parts of the body are made equal to the barrel caliber d in the form of two arcs with angular size 90° and symmetrical relative to the central vertical and horizontal planes of the brake body, a conical part with a length of 1.53d and a cylindrical part with a length of 2.35d are tides of the housing in the horizontal area symmetrically relative to the central vertical and central horizontal planes with a profile width equal to 2.25d , profile height equal to 1.32d, side windows made in the bosses of the cylindrical part of the brake housing, rectangular in shape with a height of 1.06d and a width of 1.49d and the center of the window being located from the front wall of the brake housing at a distance of 1.16d, on the inner top and On the lower horizontal surfaces of the tides of the cylindrical part of the body, tides are made, the beginning of the tides coincides with the plane of the end of the conical part of the body and the beginning of the cylindrical part, the total length of the tide is equal to 0.72d, the length of the front part of the tides is 0.13d, the radii of the profile of the tides are respectively 5.15d and 0.21d, the front wall of the brake is connected to the walls of the cylindrical part of the body with a rounding equal to 0.25d.