Center of pressure analysis for bullet angle of attack using computational fluid dynamic

Abstract

The center of pressure (CP) is the point focused on drag and lift force. Because of its particular shape, the CP of the bullet is located in front of its center of gravity (CG). A bullet flies at an angle of attack. This paper is to observe the relation between the center of pressure (aerodynamics forces) and angle of attack using Computational Fluid Dynamics (CFD). Center of Pressure (CP), coefficient drag (Cd), and coefficient lift (Cl) were investigated at a different angle of attack (0°,4°,6°, and 12°). Maximum Cd is 1.268 and Cl is 0.75 at the angle of attack 12°. The result shows that CP moves closer to CG with an increasing angle of attack, also with Cd and Cl. The increasing drag and lift forces cause unstability of the bullet. The overturning moment is very important to make sure bullet is rotating. Overturning moment improves the gyroscopic effect to stabilize the bullet movement during the air.