Effect of Cavitator on Supercavitating Vehicle Dynamics

In this paper, a linear mathematical model of a supercavitating vehicle is developed to investigate some of the physical factors affecting stability and control. This model provides a link between the simulation dynamics and the assumed physical vehicle characteristics. In this paper, the static and dynamic stability of the pitch plane dynamics of the vehicle is considered and the effect of cavitator shapes, namely a disk cavitator, a 45 cone, and a 15 cone on the vehicle stability, is determined. All three cavitator shapes resulted in unstable vehicles when operating in nonplaning conditions, with the disk cavitator the least destabilizing. Neglecting the small tangential forces on the disk cavitator is confirmed to be reasonable, but in general, the vehicle static stability characteristics depend on the cavitator tangential forces. The vehicle mathematical model uses static experimental data of hydrodynamic coefficients for the disk cavitator.