Abstract: The seakeeping performance of a small-waterplane-area twin hull (SWATH) installed with stabilizing fins was investigated on the basis of the three-dimensional translating-pulsating (3DTP) source Green function. The effects of the hydrodynamic interaction between twin hulls, the viscous damping and the lift generated by the stabilizing fins were included. The numerical method was validated by comparison with the test results of a SWATH vehicle called SWATH-M. Then the influences of the forward speed on the seakeeping characteristic of SWATH-M were studied, and the effects of the viscosity and stabilizing fins on the hydrodynamic forces of the total hull were analyzed. The results obtained from the present method based on the 3DTP source Green function show good agreement with those of the test. The transfer functions of both heave and pitch modes depict two peak values with the wavelength increase. With the increase of the forward speed, the peak value in the relatively short wave zone increases while the peak value in the long wave zone decreases. The effects of the viscosity and stabilizing fins have obvious contribution to the heave-heave damping, the pitch-pitch damping, the imaginary part of heave force and the real part of pitch moment.

Key words: small-waterplane-area twin hull (SWATH), three-dimensional translating-pulsating (3DTP) source Green function, seakeeping, frequency domain