Identification and simulation mathematical model of thermo and physical loading of a small-caliber artillery barrel

An artillery shot is a complex gas and thermodynamic process of rapidly converting the chemical energy of gunpowder into heat, and then into mechanical work of moving the projectile and the recoil parts of the artillery gun. A distinctive feature of the use of aviation artillery weapons is the short time during which firing from an aircraft at a target is possible, which requires the production of not one artillery shot, but the firing of the maximum number of shells with minimal interruptions between bursts of shots. An analysis of the existing physical concepts of the processes occurring in a small-caliber artillery barrel (hereinafter referred to as the barrel) makes it possible to single out the main quantitative characteristic of the temperature state that affects the quality of the functioning of aviation artillery weapons - the temperature field of the barrel. The temperature field, high in level and gradients, formed in the barrel wall during firing, bursts and series of shots, has a significant impact on the reduction in the tactical, technical and operational characteristics of aviation artillery weapons. Therefore, the problem of synthesizing a mathematical model of thermophysical loading of a wellbore (hereinafter referred to as the model, if it is clear from the context of the presentation of the material that we are talking about the developed model) and the definition of the temperature field is of great importance for solving a number of practical applications. These include: assessment of bore wear depending on heating; analysis of the thermal strength of the barrel material; analysis of the conditions of projectile guidance along the bore and cartridge case extraction during firing; evaluation of various ways and methods of artificial cooling of shafts; determination of the safety of aviation artillery weapons by eliminating the event of self-activation of a thermally loaded cartridge located in a barrel heated by firing; ensuring the conditions for maintaining the operability of fuses, etc. At the same time, an adequate calculation of non-stationary heat transfer in the bore is difficult, due to the incomplete reliability of the initial data and the dynamics of fast processes in the use of aviation artillery weapons. The aim of the work is to improve mathematical tools that describe the thermodynamic states of the barrel based on the basic functional dependencies of internal ballistics and a dispersed combination of heat transfer methods and finite differences. Numerous and comprehensive testing of the synthesized model, comparison of the calculation results with the data of the classical theory, self-similar solutions and experimental data confirmed the reliability and predetermined the sufficient suitability of the model for its intended use as the objects of research become more complex.