The Effect of Curved Portion Variations on the Aerodynamic Performance of Bullets

In modern battlefield, the requirements for long-range guidance and efficient damage of projectiles are increasing. The curved portion of projectiles is an important factor affecting the ballistic stability and aerodynamic characteristics. The optimization design of the curved portion of projectiles is of great significance for improving the guidance distance, accuracy, and the flight stability of projectiles. In this paper, a design method of the curved portion based on the exponential curve is proposed. The aerodynamic characteristics of projectiles of the curved portion based on the exponential curve and the existing typical curved portion under various Mach numbers (0.8, 1.5, and 3 Mach numbers) and various angles of attack (0, 10° and 20°) were numerically simulated by ANSYS Fluent software. The simulation results showed that when flying at various Mach numbers at zero attack angle, the projectile with logarithmic curve arc has the largest drag and drag coefficient, while the exponential curve arc has the smallest drag and drag coefficient. The drag coefficients between the two types of projectiles are 4.9, 14.5, and 13.7%, respectively, at various velocities. As compared with zero attack angle, the lift coefficient of exponential curve increases by 0.08 and 0.18 at the 10° attack angle and the 20° attack angle, and the change in the drag coefficient is only 0.008 and 0.077, which also indicates that the projectiles with the exponential curve arc have the better aerodynamic characteristics.