Non-linear simulations of wave-induced motions of a floating body by meansof the mixed Eulerian-Lagrangian method

A non-linear calculation method based on the mixed Eulerian-Lagrangian (MEL ) method is presented for wave-induced motions of a two-dimensional floatin g body. Attention is focused on an effective calculation of the hydrodynami c force associated with the temporal derivative of the velocity potential i n the Bernoulli pressure equation. Unlike other existing methods, the accel eration field can be computed simultaneously with the velocity field, which contributes greatly to a reduction in the computation time. Computations a re performed for a wall-sided model and a flared model, and numerical resul ts of the waves at upwave and downwave positions and the body motions (sway , heave and roll) are compared with corresponding experiments. The overall agreement is very good, confirming the validity of the present method. The parametric oscillation in roll, observed for the hared model, is also discu ssed.