Mine Drop Experiment (MIDEX)

Abstract

The Navy's Impact Burial Prediction Model (IMPACT 25) determines the amount of burial a mine experiences upon impacting the marine sediment. Impact burial calculations are derived primarily from the sediment characteristics and from the mine's two-dimensional air and water phase trajectories. Accurate burial prediction requires that the model's air and water phase trajectories reasonably mimic the objects true trajectory. IMPACT 25 assumes that the objects are cylindrical in shape and calculates the air and water phase trajectories entirely from momentum equations. In order to determine what effect a varying center of mass has on a mine's water phase trajectory, a Mine Drop Experiment was conducted. The experiment consisted of dropping three cylinders of various lengths into a pool where the trajectories were filmed from two angles. The controlled parameters were, the ratio of mine length to diameter, initial velocity, center of mass position and drop angle. Results indicate that center of mass position has the largest influence on the object's trajectory and that accurate trajectory modeling requires the inclusion of both momentum and moment equations.