Rapid Assessment of Small Changes to Major Gun and Projectile Dynamic Parameters
Final rept. Jan-Aug 96
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
The U.S. Navys 5-in 54-cal. 554 gun system Mark Mk 45 was subjected to first-order dynamic analysis tools that allowed rapid assessment of ballistic dispersion of a typical naval high explosive projectile. The interior ballistics high velocity gun version 2 IBHVG2 modeled the 5-in propelling charge Mk 67, and gun barrel centerline data were obtained from two 554 Mk 19 gun barrels. The Little RASCAL program was used to estimate the tipoff angles and angular rates for the Mk 64 5-in projectile, and the PC-PRODAS computer program was used to estimate the projectile yaw and yaw rates resulting from the bore and bourrelet clearance. The tipoff angles and rates obtained for the Little RASCAL program were then combined with the yaw data to establish a matrix of possible worst-case conditions of initial projectile yaw and yaw rate. A total of 32 possible muzzle exit conditions were identified and used as initial conditions for a 6 degrees of freedom trajectory program. The resulting variation in range obtained from the 32 trajectory calculations was used to calculate the range probable error. The results obtained from this relatively simple analysis technique have shown very good correlation with ballistic dispersion measurements made during actual firing tests.