Investigations of Middle-Caliber Anti-Aircraft Cannon Interior Ballistics including Heat Transfer Problem in Estimation of Critical Burst Length

Abstract

Numerical and experimental investigations of armament systems are an important part of modern design processes. The presented paper reports problems that were encountered on the theoretical analysis of the performance of 35 mm anti-aircraft cannon and the way in which they were solved. The first problem concerns the application of results of closed vessel tests of used propellant in interior ballistics simulations. The use of a nonstandard form of the gas generation rate equation solved this problem. The second problem concerned the assessment of projectile–barrel interaction. The barrel resistance was estimated making use of finite element analysis. The third problem arose from the need to determine the heat transfer from propellant gases to the barrel. The employed formula for the heat exchange coefficient and 2D modelling of the heat conduction in the barrel provided the solution. Selected elements of the theoretical model were validated by shooting range experiments and data provided by the ammunition producer. Using the considered approach, crucial ballistic parameters (maximum propellant gas pressure and muzzle velocity) were estimated with an error of less than 6.0%, without application of additional fitting coefficients. The numerical estimation of the barrel external surface temperature provided a relative discrepancy with the experimental data lower than 6% and enabled the estimation of the critical burst length, equal to 14 shots.

Application of the new hybrid model LMAW-G-EDAS multi-criteria decision-making when choosing an assault rifle for the needs of the army

“…The service life of the tube (C5) is a characteristic defined by the number of shots fired, without the characteristics of the pipe slipping significantly and are within the set limits. The method of manufacture and the types of materials used in the manufacture of pipes have a crucial impact on its service life as well as the pressure and temperature that are created in the pipe after firing (Fikus et al, 2022). The most common standard tolerated for caliber deviations is 0.07 mm, and the corrosion of pipes over 50% directly affects the accuracy and precision of shooting.…”

Studies on Influence of Chromium Layer on Inner Surface of Steel Tube on Heat Transfer

“…The course of the temperature of the outer surface of the tube in zone 26 obtained in the validation of the model is shown in Figure 10. Validation of the calculation results was carried out in the form of a comparison of the temperature increase after six heat impulses in relation to the RT on the outer surface of the tube in zone 26 with analogous results for such a tube in the same zone [9]. The course of the temperature of the outer surface of the tube in zone 26 obtained in the validation of the model is shown in Figure 10.…”

“…The low service life of a tube loaded with an intense heat impulse is related to the erosion of its internal surface caused by mechanical and chemical factors [1][2][3][4][5][6][7][8][9][10][11]. Studies have demonstrated that the tube's wear mechanism is directly influenced by the maximum temperature of its surface [12].…”

Experimental Studies of Thermophysical Properties and Microstructure of X37CrMoV5-1 Hot-Work Tool Steel and Maraging 350 Steel

“…Such deterioration is manifested by the network of cracks and degradation of the protective chromium coating [ 1 , 2 , 3 , 4 , 5 , 6 ]. The temperature of the inner surface of the barrel of such weapons during a series of shots exceeds 1100 °C [ 7 , 8 , 9 ]. This is indicated by the results of numerical simulations of heat transfer and experimental tests, which showed the presence of molten copper in the gaps under the galvanic layer of chromium [ 2 ].…”