Estimation of Priming Mixture Force

Abstract

This paper presents the results of the estimation of the priming mixture force for primers used in 12.7 mm ammunition. The method of estimation is based on the results of pressure measurements in a closed chamber into which the products of the combustion of the priming mixture flowed. The capacity of the chamber was changed by inserting sleeves of various volumes. Another estimation of the force value was performed using the results of earlier investigations in which the chamber was filled with glass balls. The determined values of the force were compared with the values estimated based on the accessible literature data. The obtained estimations of the force value are of the same order of magnitude as the force value of black powder. This justifies the use of black powder characteristics for the assessment of the thermodynamic properties of priming mixture combustion products in interior ballistics calculations. The time of action of the investigated primer was determined using the optical recording of the outflow of the priming mixture combustion products into an open space. To facilitate the interpretation of the results of the experiments, a theoretical model was used.

Influence of the Ignition Method on the Characteristics of Propellant Burning in the Context of the Geometric Burning Model

“…Graph φ ex (z) for cartridge primer ignition reflects the dynamic nature of the process. In accordance with the results of the experimental tests [73] and the analysis carried out in [74], the pressure value inside the cartridge primer is about 100 MPa. A large difference in the pressure values inside the cartridge primer and inside the chamber causes an intensive outflow of combustion products of the ignition mass through the cartridge primer channel.…”