LONGITUDINAL STABILITY AND CONTROL OF CANARD HYDROFOIL CRAFT

A study of longitudinal stability and control of canard hydrofoil-supported craft of the 110long-ton weight class, in both calm and disturbed seas, is presented. Configurations involve craft with all foils fully submerged, all foils surface-piercing, and foils of hybrid arrangement (submerged forward, surface-piercing aft and vice versa). As a design aid, effects of variations of major parameters such as speed, c.g. location, foil spacing, dihedral angle, etc. are illustrated. It is shown that autopilot stabilization of the submerged-foil reference craft is required in waves. Although the surface-piercing-foil reference craft is inherently stable in both smooth water and disturbed seas, its capabilities in waves are more limited than those for the submerged-foil vehicle. Also presented is a comparison of canard and conventional configurations in calm and disturbed seas. (Author)