Wave Effect on Trajectory of High-Speed Rigid Body in Water Column

Waves form when the water surface is disturbed, for example, by wind or gravitational forces. During such disturbances energy and momentum are transferred to the water mass and sea-state is changed. For shallow water regions, the bottom topography affects the waves dramatically. Waves may cause evident slant of the ocean surface with large inclination angle of about 55 o . When high-speed rigid body strikes on the wavy ocean surface, random ocean slope largely affects its underwater trajectory. Identification of such an effect is a key point in the prediction of fast moving rigid body in water column. The probability density equation (PDF) of the ocean wave slopes was used to generate stochastic surface slope. A 6-dgree of freedom (DOF) model of fastmoving rigid body is used with the stochastic sloping surface as its water-entry condition. The PDFs of the body location and orientation are obtained from results of 6-DOF model runs. From temporal change of these PDFs, wave effect on trajectory of high-speed underwater rigid body has been identified.