Pseudocylinder Parametrization For Mine Impact Burial Prediction

The United States military has undergone numerous changes since the end of the Cold War. Specifically, the U.S. Navy experienced a shift in the area of engagement from the “blue water” water depth greater than 100 m to littoral regions of the world. The sea mines become the big threat in the naval operations. Within the past 15 years three U.S. ships, the USS Samuel B. Roberts FFG-58 , Tripoli LPH-10 , and Princeton CG-59 have fallen victim to mines. The total ship damage was $125 million while the mines cost approximately $30 ,000 1 . Let x ,y be the horizontal coordinates and z the vertical coordinate. A two-dimensional model called IMPACT28 was developed to predict the mine’s movement in the x ,z cross section 2 . The model contains two momentum equations in x and z directions and one moment of the momentum equation in the y direction , and predicts the mine’s center of mass COM position in the x ,z plane and the rotation i.e., the mine’s orientation around the y axis. Since the mine’s movement in IMPACT28 is strictly in the x ,z plane, it is very hard to include the motion of fluid in the two-dimensional model, because it is impossible to lay a mine in the same direction of the fluid velocity. In the littoral zone, the water velocity is not negligible. The application of the two-dimensional model for the operational use is limited. Recently, a three-dimensional recursive model IMPACT35 has been developed to predict the rigid cylinder’s or cylindrical mine’s translation velocity and orientation in fluid involving nonlinear dynamics, fluid–structure interaction, and instability theory 3–5 . However, the Navy operational mines are usually not cylindrical. The existing model should be extended from the cylindrical mines to more general shapes of mines with nose and tail.