Correlation of Bullet Dispersion and Transverse Barrel Tip Displacement on aFiring Phalanx Gun System

摘要

The PHALANX Close-In Weapons System (CIWS) is a very important part of the anti-ship missile defense structure of the U.S. Navy. The PHALANX gun system currently experiences random and variable bullet dispersion which diminishes its ability to destroy its intended targets. The more that is understood about parameters that control PHALANX gun dispersion performance, the more the Navy can increase its performance and hence, ship survivability. The research described in this thesis is an attempt to correlate measured bullet dispersion with transverse barrel tip displacement data derived from measured barrel tip acceleration data taken on a firing PHALANX gun system. The goal of this project is to relate barrel tip vibration, which can be measured on a gun at any location, to bullet dispersion, which can only be measured on a test range. Acceleration measurements were made on a firing PHALANX gun at the Navy Air Weapons Station, China Lake, CA. From these measurements were derived the vertical and horizontal components of gun barrel tip displacement by direct time integration and by a fourier transform procedure. It was found that the resulting displacement time records were contaminated by a large, spurious, low frequency contribution, the source of which is unknown. It is speculated that it is most likely due to the effect of temperature on the accelerometers. A procedure was developed to remove the low frequency trend from the displacement time records using cubic spline smoothing. The resulting horizontal and vertical barrel tip displacement records were compared to bullet dispersion data gathered during the gun firing.