Numéro : 2762 - Year : 2021
Development of a new method for the evaluation of the ship behaviour on waves with forward speed
Xiaobo CHEN - Sime MALENICA - Quentin DERBANNE - Research Department, Bureau Veritas, Paris, France
Youngmyung CHOI - Dept. Naval Architecture and Ocean Engineering, PNU, Busan, Republic of Korea
By choosing the ship-shaped stream (double-body flow) as the base flow over which is superposed the perturbation flow containing steady and unsteady components, a consistent linearisation of perturbation flows, in particular, a new boundary condition on the free surface, is formulated. A new set of boundary integral equations (BIE) are established by applying the Green's theorem. The resultant BIE includes a localized free-surface integral in the vicinity of ship but without the troublesome water-line integral present in the classical Neumann-Kelvin approach (NK). The Green function associated with a pulsating and translating source is reformulated by considering the viscous effect so that the complex singular and highly-oscillatory behaviour disappear naturally. The integration of Green's function over at panels is evaluated accurately by applying new analytical formulations. With extra integral equations imposed over the waterplane inside the ship hull to ensure the zero potential outside the fluid domain, a new sound base of solution for ship seakeeping with forward speed is thus established. Numerical results in good agreement with experimental measurements show that this new method provides a reliable and practical method to evaluate wave loads and induced ship motions.
This paper is written in English