Another Analytical Approach to Predicting Munition Trajectories

Analysis presented here addresses a previous problem concerning free-flight projectiles governed by the two-dimensional, point mass equations representing drag as a power law. Down-range distance is taken to be the independent variable which yields a third-order differential equation governing the projectile's flight. An approximate solution is obtained which is shown to be very accurate for gun elevation angles up to 30 degrees. Previously examined engineering characteristics for flat fire are reconsidered here with nonzero elevation angles over a range of projectile flight parameters. An important change from previous work is that gravity is never neglected when using the various parameterized drag curves, thus the velocity drag relation has gravity dependence. Firing table drag data are employed to study several examples using this analysis. Comparisons between analytical and numerical models to previous work are presented. This report shows that the results given here offer another simple means to examine the performance of low-yaw/high-velocity projectiles where the launch angle is as high as 30 degrees. The original document contains color images.