Effects of Different Nose Cone Designs on Trajectory and Impact Angle of Smart Fire Extinguishing Ammunition

Abstract

A nose cone is the conically shaped tip part of a missile, bomb or aircraft, used to regulate the behavior of oncoming airflow and minimize drag. In this study, the effects of different nose cone designs on the trajectory and impact angle of smart fire extinguishing ammunition were investigated. For this purpose, three different types of ammunition with different nose cone profiles were designed: spherically blunted conic nose cone, spherically blunted tangent ogive nose cone and truncated tangent ogive nose cone. A virtual wind tunnel was created in the computer environment and a CFD software was used to calculate the drag coefficients for each design. By applying Newton's second law of motion, the horizontal distance the ammunition received before striking fire, impact speed, and impact angle were calculated. The obtained results were compared using One-Way ANOVA (analysis of variance) in order to determine whether there is statistical evidence that the associated population means are significantly different. It was determined that the three types of nose cone designs examined did not have a significant effect on the impact speed, impact angle and horizontal distance of the ammunition at the investigated speeds and altitudes. On the other hand, flame detection, distance measurement and impact sensors, which should be in the smart fire extinguishing ammunition, should be on the plane at the front of the ammunition and in contact with the external environment. In order to place these sensors in the nose cone, a truncated tangent ogive nose cone was chosen as the nose cone for the smart fire extinguishing ammunition.