Preliminary Investigation of Roll Controllability of a Hydrofoil Small Waterplane Area Ship(HYSWAS),

摘要

An analytical investigation on the feasibility of roll control of a hydrofoil small waterplane area ship (HYSWAS) in waves is made. Wave-excited roll moments on the HYSWAS at the foilborne speeds of 18.5 knots to 25 knots are computed for the wave headings from the direction of stern quartering, beam, and bow quartering. The root mean square of the angles of deflection of foils under incidence control which are required to counteract the wave-excited roll moments are determined for various sea states. The sea states are represented by Bretschneider's sea spectra formula. For a gross assessment of seakeeping qualities of the ship, the probable numbers of free-surface contacts on the bottom of the upper hull for various sea conditions and ship speeds are predicted. (Author)