RU92169U1 - Artillery shell - Google Patents

Abstract

An artillery shell comprising a body with a head compartment and a warhead and aft compartment with a device for increasing flight range, comprising a storage chamber and a throttle device, characterized in that the device for increasing flight range is provided with a support corrugated disk and a radially corrugated membrane superimposed on the corresponding profile corrugation of the support disk and mounted on its outer surface, and in the center of the membrane a throttle device with the possibility of axial movement fixed on the membrane, the corrugated membrane is made in the form of a coaxial combination of zigzag corrugations with rounded ends, between which there are cylindrical sections of width h with the following ratio:! ! where K is the coefficient characterizing the allowable plastic deformation of the membrane material; ! r is the radius of curvature of the ends of the membrane.

Description

The invention relates to ammunition, in particular to artillery shells, in which to increase the flight range when the projectile moves along the barrel, the energy of the gases in the projectile space is accumulated in the projectile, and after the projectile leaves the barrel, the aft part is lengthened, giving it a conical shape form.

An analogue of the proposed device is a device for increasing the flight range of an artillery shell by using a telescopic extension. An artillery shell comprising a body with a head and aft compartments, a warhead and a device for increasing flight range, while the device for increasing flight range is made in the form of a telescopic stern extension, which contains a hollow fairing rigidly fixed to the aft compartment, and a movable cap placed in it with the possibility of axial movement with subsequent fixation using an expanding spring ring. The hollow cowl and hood are made in the form of cylinders mated with truncated cones of the same taper. A throttle device is located in the center of the cap, which connects the projectile space with the storage chamber formed by the bottom cut of the projectile and the movable cap (RF patent No. 2251068 in class F42B 10/38 with priority dated December 8, 2003, published on April 27, 2005).

The above analogue has several disadvantages:

- in the case of using one telescopic extension, you can get only a truncated cone, which will reduce, and not completely get rid of bottom resistance, that is, the flight range will increase slightly;

- in the case of using several telescopic extensions, you can get a full cone, however, such a design will significantly increase the mass of the projectile and will have low reliability.

The prototype of the proposed device is an artillery shell with a deformable in flight aft (RF patent No. 2358228 in class F42B 10/38 with priority dated 08/13/2007, published on 06/18/2009). An artillery shell comprising a body with a head compartment with a warhead and aft compartment with a device for increasing flight range, comprising a storage chamber and a throttle device, while a support ring and a corrugated membrane with a central hole are introduced into the device for increasing flight range, the corrugated membrane being rigidly mounted on the outer diameter of the aft compartment, resting on the outer end surface of the storage chamber, and the corrugated membrane is made with half overlap corrugation rings, the radial width of which is determined by the following relationship:

,

where l _i is the radial width of the i-th corrugation,

d _iav - the average diameter of the i-th corrugation,

K is the coefficient characterizing the allowable plastic deformation of the membrane material.

The above prototype has several disadvantages:

- the location of the corrugations overlapping requires the use of a protective cap that protects the thin-walled corrugations of the membrane from mutual deformation and collapse;

- the manufacture of a membrane of this form is quite difficult in the technological plan and requires significant material costs.

The objective of the present invention is to increase the flight range of an artillery shell by improving aerodynamic quality by reducing bottom drag by giving the aft of the projectile in flight a smoothly streamlined flow of air without changing the nominal dimensions of the projectile before firing and with a minimum mass of the transformed aft part.

The problem is solved in such a way that an artillery shell containing a body with a head compartment, a warhead and aft compartment with a device for increasing the flight range, containing a storage chamber and a throttle device, while the device for increasing the flight range is equipped with a supporting corrugated disk and a radially corrugated membrane superimposed on the corresponding profile corrugation of the disk and fixed on its outer surface, and a throttle device with the possibility of sevogo move, fixed on a membrane, wherein the membrane is corrugated in a plurality of zigzag corrugation coaxial with rounded ends along the radius r, between which there are cylindrical portions of a width h in the following ratio of geometrical sizes:

where K is the coefficient characterizing the allowable plastic deformation of the membrane material.

Figure 1 shows a General view of an artillery shell with a device for increasing flight range.

Figure 2 shows a view of an artillery shell after a device is activated to increase flight range.

The projectile contains a housing 1 with a head 2 and aft 3 compartments. The warhead is located in the head compartment 2. In the aft compartment 3 there is a device for increasing flight range, made in the form of a deformable tail fairing, which contains a radially corrugated membrane 4, the outer edge of which is rigidly fixed on the supporting corrugated disk 5, and in its center is a throttle device 6 connecting the projectile space 7 with the accumulation chamber 8 formed by the bottom cut of the projectile and the supporting grooved disk 5. The length of the generatrix of the expanded cone is determined based on the condition of providing a taper angle of 20 °, at It is understood that the radially corrugated membrane is not only straightened, but also stretched. To take this fact into account, a coefficient K characterizing the allowable plastic deformation of the membrane material and equal to the value of the allowable elongation of the membrane material δ was introduced into the formula relating the width of the cylindrical section and the radius of curvature of the radially corrugated membrane. The values of δ (V.I. Anufriev “Handbook of the designer-mechanical engineer”) are, for example, for Steel 15-0.2; for alloy VT1-00-0.25. The throttle device 6 is designed in such a way that does not allow the rapid outflow of high pressure gas from the storage chamber 8 when the artillery shell leaves the barrel. The location of the throttle device in the center of the radially corrugated membrane 4 allows to exclude the influence of a gas stream flowing from the storage chamber 8 on the flight path of the artillery shell. The arrows p _k and p _vn show the gas pressure acting on the radially corrugated membrane 4 when it is deformed (p _k - in the barrel, p _k - when the membrane is deformed in free flight).

The artillery shell works as follows.

When fired by powder gases, the projectile is accelerated in the barrel and at the same time, throttle device 6 accumulates high-pressure gas in the storage chamber 8, which is formed by the bottom cut of the projectile and the corrugated supporting disk 5. The corrugated membrane 4 is compressed when the projectile is in the barrel to the supporting corrugated disk 5, therefore, to ensure the necessary strength of the structure does not require a large thickness of its walls. After the projectile leaves the barrel, the ambient pressure (pressure behind the bottom cut of the projectile) becomes much lower than the gas pressure in the storage chamber 8. Due to the pressure difference, the throttle device 6 begins to move in the axial direction, while the radially corrugated membrane 4 begins to straighten and lengthen under the action internal pressure takes on a form convenient for flowing around with a stream of air. The straightened and elongated radially corrugated membrane 4, due to its initial shape, ultimately forms a tail cone in the form of a cone with an angle of inclination of the generatrix to the longitudinal axis of 20 °, this allows to minimize the bottom aerodynamic drag and thereby increase the flight range of the artillery shell.

Using the proposed device will reduce the coefficient of total aerodynamic drag of the projectile by 25-30%, which will lead to an increase in the range of the projectile by 15-20%. These performance indicators of the proposed solutions are confirmed by the results of numerical simulation of the flight of a modernized artillery shell.

Claims (1)

An artillery shell comprising a body with a head compartment and a warhead and aft compartment with a device for increasing flight range, comprising a storage chamber and a throttle device, characterized in that the device for increasing flight range is provided with a support corrugated disk and a radially corrugated membrane superimposed on the corresponding profile corrugation of the support disk and mounted on its outer surface, and in the center of the membrane a throttle device with the possibility of axial movement fastened to the membrane, while the corrugated membrane is made in the form of a coaxial combination of zigzag corrugations with rounded ends, between which there are cylindrical sections of width h with the following ratio:

where K is the coefficient characterizing the allowable plastic deformation of the membrane material; r is the radius of curvature of the ends of the membrane.