We present in this paper a semi-analytical solution for second-order wave diffraction by a vertical circular cylinder in bichromatic waves. On the base of the usual assumption of an irrotational flow, the wave-diffrac...We present in this paper a semi-analytical solution for second-order wave diffraction by a vertical circular cylinder in bichromatic waves. On the base of the usual assumption of an irrotational flow, the wave-diffraction problems at second-order sum-frequency and difference-frequency are considered. The corresponding second-order diffraction potentials are decomposed into three parts, these are associated with the second-order incident wave, the quadratic forcing terras on the free-surface due to the first-order potential, and the linearised free-wave component resulting from the boundary condition on the body surface. A particular solution which exactly satisfies the inhomogeneous free-surface condition has been derived. Numerical results for the quadratic transfer functions of the second-order force components are given, and are compared with those obtained using numerical solutions (Kim & Yue, 1990,Moubayed & Williams 1995). These quadratic functions are useful in calculating the exciting forces on a circular cylinder of large dimension, fixed in irregular wave fields.展开更多
文摘We present in this paper a semi-analytical solution for second-order wave diffraction by a vertical circular cylinder in bichromatic waves. On the base of the usual assumption of an irrotational flow, the wave-diffraction problems at second-order sum-frequency and difference-frequency are considered. The corresponding second-order diffraction potentials are decomposed into three parts, these are associated with the second-order incident wave, the quadratic forcing terras on the free-surface due to the first-order potential, and the linearised free-wave component resulting from the boundary condition on the body surface. A particular solution which exactly satisfies the inhomogeneous free-surface condition has been derived. Numerical results for the quadratic transfer functions of the second-order force components are given, and are compared with those obtained using numerical solutions (Kim & Yue, 1990,Moubayed & Williams 1995). These quadratic functions are useful in calculating the exciting forces on a circular cylinder of large dimension, fixed in irregular wave fields.
