RU2075030C1 - Powder charge of artillery system with enhanced range of fire - Google Patents

Abstract

FIELD: ammunition powder charges for recoilless guns. SUBSTANCE: powder charge is made as a set of powder cartridges armored on the external surface, with cylindrical ducts; the thickness of the set of powder cartridges is proportional to the time of action of the maximum pressure of gases, and the length of the cylindrical ducts of cartridges is taken to be equal to: D_o= g•β/2πq(π•R•T-P)•(S/u₁)², where g - free fall acceleration; β - coefficient taking into account the variation of gas inflow at a deviation of the burning law from the geometric law, heat exchange, etc., as well as the variation of gas flow at burning of cartridges at the ends; g - shell weight; r - powder density; R - gas constant; T - absolute temperature of gases in the space beyond the shell; S - bore cross- section area, rifling grooves inclusive; u₁ - rate of powder burning at a pressure equal to 1; P-pressure. Besides, relation is given for the condition of barrel recoillessness. EFFECT: enhanced efficiency. 2 cl, 1 dwg

Description

 The invention relates to military equipment and can be used in artillery systems to increase the muzzle velocity of a projectile and firing range.

 Artillery systems with increased firing ranges are known, for example, the project of the German Hochdryukpumpe system (project No. 51), designed to shell London during World War II (Technical specifications of the system are given in the magazine Around the World N 11, 1973). The system consisted of a barrel with parts of the charge placed along its length, which were activated alternately by the projectile during its movement along the barrel, which maintained the necessary pressure in the projectile space to obtain the desired muzzle velocity of the projectile. For each part of the charge, its own combustion chamber was created, which complicated the design, and the sequence of their use caused unreliability in operation, which would affect the internal and external ballistics and affect the range and accuracy of the barrels.

 Also known are artillery systems described in the book of M.E. Serebryakova "Internal ballistics of barrel systems and powder rockets" published by Oborongiz, 1962. The powder charge of one of which was a recoilless gun with axial gas removal (chapter XII), taken as a prototype.

 In FIG. 1 shows a structural diagram of this gun, and in FIG. 2 - pressure curves of powder gases and curves of the velocity of the projectile in the bore for the prototype and the present invention.

 A sleeve 2 is inserted into the barrel 1 of the gun (Fig. 1), with a powder charge 3 placed therein and an ignition device 4. On the one hand, a shell 5 is inserted into the sleeve, on the other there is a bottom with an opening. The bottom of the barrel ends with an expanding once-through nozzle 6, communicating with the hole in the sleeve and with the atmosphere. The hole in the sleeve is closed by the pallet 7. Fine-grained gunpowder is used as a charge (p. 675; Hereinafter, a page from the specified book by M.E. Serebryakov will be put in brackets).

 When the igniting device 4 is activated, the powder charge 3 lights up, the pan 7 is kicked out from the action of the pressure of the resulting gases, and the projectile 5 moves along the barrel 1.

 Part of the gas performs work on moving the projectile in the barrel (gas operation in the projectile space), providing a given internal ballistics, and the other part of the gas moves in the opposite direction through the nozzle 6, creating a reactive force balancing the recoil force of the barrel (passive part of the charge).

 In FIG. Figure 2 shows the nature of the pressure curves 1 and velocity 2 for conventional artillery systems of the classical scheme. The pressure P of the powder gases in the projectile space and the velocity V of the projectile vary in function of the path l of the projectile in the barrel and in time t according to well-defined laws depending on the characteristics of the powder charge, projectile and gun.

The hatched area of the diagram of pressure curve 1 along the way determines the work of the gases of the active part of the charge, which converted to the kinetic energy of the projectile, and the larger this area, the greater the muzzle velocity V _{d of the} projectile, the greater the range.

Curve 1 for recoilless guns is “sharp” (p. 682), since the powder burns out quickly, the pressure reaches its maximum value Р _max , and the further movement of the projectile in the barrel occurs under the action of pressure from expanding gases, and since some of the gases are ejected from the projectile space through nozzle, the pressure curve drops sharply, which reduces the area of the diagram and accordingly decreases the muzzle velocity of the projectile.

 The invention is intended to eliminate this drawback by providing the necessary gas inflow from burning a charge to maintain maximum pressure in the projectile space at a given path of projectile movement in the barrel, which will increase the area of the diagram and accordingly increase the muzzle velocity of the projectile.

 In the present invention, as a charge 3 (Fig. 1), a set of powder checkers having cylindrical channels is used, which provides a continuously increasing intensity of gas generation during charge burning.

 The use of charge and a description of the process of the shot are similar to those in the prototype.

The calculation established the total length of the cylindrical channels of the checkers, at which at any given time the necessary gas inflow from the burning of the charge is provided to maintain maximum pressure in the projectile space on a given path l _k (Fig. 2) of the projectile in the barrel. The length of this path is set and determined by the burning time of the charge, i.e., the thickness of the arch of combustion of the powder bombs, along cylindrical channels.

The pressure diagram along the way is more complete (curve 3), the muzzle velocity increases to V _{d max} (curve 4) and, accordingly, the firing range increases.

 Thus, given the magnitude of the maximum pressure in the bore and the thickness of the arch of the combustion of powder bombs, theoretically, you can get any muzzle velocity of the projectile. In practice, this is limited by the thickness and length of the barrel.

Part of the gases during the combustion of the charge is released into the atmosphere (passive part of the charge) through the nozzle 6 (Fig. 1), creating a reactive force. To ensure recoillessness of the barrel, the reactive force should be equal to and opposite to the recoil force of the barrel. The magnitude of the reactive force is determined by the flow of gases through the nozzle, which depends on the initial diameter d _o channel drafts. From this condition, the diameter of the channel of the checkers, which ensures the recoillessness of the barrel, is determined.

Claims (2)

1. The powder charge of an artillery system with increased firing range, placed in the projectile space communicating with the atmosphere by a hole, for example, an expanding nozzle, made in the form of a set of powder checkers, booked on the outer surface, with cylindrical channels, characterized in that, in order to increase the muzzle the velocity of the projectile by maintaining the maximum pressure of the gases in the projectile space at a given path of the projectile in the barrel, in it the thickness of the arch of powder bombs of a continuously burning charge the depth is proportional to the duration of this pressure, and the total length D _{0 of the} cylindrical channels of the pieces is taken equal

where g is the acceleration of gravity;
β coefficient taking into account the change in gas influx when the combustion law deviates from the geometric law, heat transfer, etc., as well as the change in gas influx during the burning of powder checkers at the ends and determined from experiments by adjusting the total length of the cylindrical channels of the blocks;
q projectile weight;
r is the density of gunpowder;
R gas constant;
T is the absolute temperature of the gases in the projectile space;
S cross-sectional area of the bore, including rifling;
U ₁ the burning rate of the powder at a pressure equal to 1;
P pressure. 2. The charge according to claim 1, characterized in that, in order to ensure recoillessness of the barrel by venting the passive part of the charge through the gas nozzle, the diameter d _{o of the} cylindrical channels of the checkers in it is

where K is the adiabatic exponent.

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