Search

A promising direction in barrel ballistics aimed at increasing the muzzle velocity of a projectile is the use of new propellants as an attached charge. This paper presents an experimental and theoretical method for determining the law of propellant combustion in a manometric experiment (in a closed volume). Within the framework of this method, a small number of experiments could be sufficient to determine a change in the law of combustion during the propellant burnout and depending on pressure. This method is demonstrated on the example of processing three experiments with model high-density propellant. The laws of combustion of high-density propellants, obtained in this study, can later be used to calculate the gas-dynamic parameters of a shot from a barrel system or a nozzle bomb (in a semi-closed volume) using these propellants. [ABSTRACT FROM AUTHOR]

This paper describes the method and results of an experimental study of unsteady burning rate of high-energy materials containing metal powder additives under depressurization at a rate of 140–160 MPa/s. The method based on stating and solving the inverse problem of internal ballistics is used to determine the unsteady burning rate. The studies are carried out for high-energy materials, including energy additives in the form of metal powders (ASD-4, ASD-6, and Alex aluminum powders), aluminum diboride, and dodecaboride. It is shown by analyzing the this study that the unsteady burning rate of high-energy materials under sharp depressurization is oscillatory and depends on the energy additive type. [ABSTRACT FROM AUTHOR]

Analytical formulas for calculating the maximum velocity of penetration of doublelayer cermet and ceramic/organic-plastic targets are obtained taking into account the structural characteristics of the target and the physical and mechanical properties of the projectile and target materials. Using these formulas, the ballistic resistance of targets was studied and the possibility of optimizing their structure was shown. The results agree qualitatively with available experimental data. The optimal relative thickness of the ceramic layer which provides maximum penetration velocity was determined at areal densities of the target of 30-50 kg/m for different substrate materials. It is found that these velocity values depend weakly on the areal density of the target and are mainly determined by the properties of the substrate material. [ABSTRACT FROM AUTHOR]

This paper presents a physicomathematical model and a method for calculating the parameters of the transition of a SRM to steady-state operation based on the design features of the propellant charge, the initial conditions in the motor, and the interrelated processes such as the formation and motion of compression waves and shock waves in the channel of the charge; the motion and mixing of the igniter combustion products containing a condensed phase with the initial gas and the combustion products of the charge; gradual heating and ignition of the surface of the charge. The developed programis used to explain the difference between the experimental pressure-time curves in the region of the transition of a large-size motor model to steady-state operation, obtained in bench tests under atmospheric conditions and on a high-altitude test facility at an initial motor pressure of 0.25 · 10 Pa. It is shown that ignition of the charge in vacuum produces more favorable conditions for heat transfer than ignition at atmospheric pressure. In the channel, this is due to an increase in the velocity of the igniter combustion products behind the transmitted shock wave, and in the submerged region and the charge slots, due to the minimum absorption of the radiation from the combustion products by the rarefied initial gas (air) present there. [ABSTRACT FROM AUTHOR]