No abstract

No abstract

A jump experiment and analysis were performed for the Ml 98 howitzer firing the Ml07 shell through short range, flat fire trajectories with a launch Mach number near 1.7. The objective was to characterize the jump performance of the system and provide a basis for identifying and possibly improving the largest contributors to jump over a broader range of firing conditions. For the short range, flat fire scenario of the present experiment, the jump performance of the system indicates that the center of gravity (CG) motion of the projectile as it exits the gun tube is a significantly larger contributor to dispersion than the aerodynamic jump. The data showed that the projectile CG motion relative to the muzzle itself is considerable and is a more dominant component of in-bore balloting in terms of dispersion compared to the in-bore angular motion. Measurements of the gun dymamics showed that while the large scale muzzle motion is more pronounced in the vertical plane than in the horizontal plane, the dispersion directly attributable to muzzle pointing angle and muzzle crossing velocity is about the same in the both directions. Measurements of muzzle velocity, drag, and yaw are also presented and can be used to determine the effect of jump components not directly measured here but important for longer ranges.

No abstract

No abstract