The course stability of an air cushion vehicle

A four-degree-of-freedom mathematical model was established to investigate the maneuverability of an air cushion vehicle (ACV). A series of constrained model experiments with horizontal-planar-motion-mechanism (HPMM) were conducted to determine the hydrodynamics over a wide range of operating conditions such as speed, drift angle, yawing angular speed and roll angle. The forces of aerodynamic, propellers and rudders were obtained by wind tunnel model experiments. The ACV's course stability was calculated for straight and oblique run. The calculation results show that the ACV is more stable with higher speed and unstable below hump. The ACV's course stability is better in a headwind than in a tailwind.