Development of 6-DOF model for underwater bomb trajectory prediction with application to the stand-off assault breaching weapon fuse improvement (SOABWFI)

Abstract

To support the development and evaluation of the Stand-off Assault Breaching Weapon Fuse Improvement (SOABWFI) program, a 6-DOF computational bomb maneuvering model is developed to accurately predict the trajectory pattern, velocity and orientation of the warheads when they are released from any of the various dispense concepts. Tests such as 1/12th scaled MK-84 bomb experiments with various water-entry velocities at SRI (near 1000 ft/s) and NPS (near 400 ft/s) provide good data on bomb trajectory and some insight into bomb orientation. With these data, semi-empirical formulas are derived for calculating drag/lift coefficients with fast water-entry, and used by the 6-DOF bomb trajectory model. This model development provides a tool to determine accurately underwater (full-size) bomb trajectory path so that the final detonation position relative to target position can be predicted.