Low frequency wave force spectrum influenced by wave-current interaction

The interaction between ocean current with sea waves plays an important rol e in the determination of the steady wave forces acting in a floating syste m and, in the limit when the velocity is small, an exact formula obtained [ J Fluid Mech. 272 (1994) 147; J Fluid Mech. 313 (1996) 39], relates the ste ady wave forces with the standard drift forces in the seakeeping problems. This result is applied here, in conjunction to Newman's approximation, to e xpress the first order influence of wave-current interaction in the second order low frequency wave force spectrum used in the study of the slow drift oscillation of a floating system. (C) 2001 Elsevier Science Ltd. All right s reserved.