NUMERICAL INVESTIGATION OF THE EFFECTS OF BULLET DIAMETER ON THE FLOW FIELD OF FIREARMS

Abstract

Basically, it is required of a weapon is to have a devastating effect. However, when the destruction effect is desired to be increased, the recoil force also increases and this situation remains current as a subject that needs to be examined. The effect that creates the recoil force in the firearm is due to the high pressure gas that occurs due to the combustion of the gunpowder in the bullet casing. Estimation of the flow area around the projectile, which is activated by the effect of high pressure, is very important in this sense. However, estimating this situation is quite complex. The complexities are due to the presence of a large number of factors, such as surface geometry, turbulence, time change in the calculation field, compressibility, gas equations, etc. One of the factors that have a direct impact on the flow zone is the bullet geometry. In this study, the effect of bullet diameter on the flow field was investigated numerically. In numerical modelling Fluent program was used. Calculations were carried out in two-dimensional axisymmetric, transient, compressible conditions. As a result of the calculations, the pressure distribution around the projectile was drawn along a position different from the barrel axis, and pressure values were shown for different time values at these positions. In addition, the velocity and temperature distributions that occur in models of different bullet diameters at different locations have also been studied. When the results were examined, it was determined that as the bullet diameter incre as observed that the temperature of the air around the bullet decreased as the diameter increased.