engleski

Non-linear Heave and Pitch Motion of Ship in Head Waves

The non-linear effects of the large amplitude oscillatory motion include on the first place the change of the ship hull configuration below the free surface. As the consequence, the equations of motion contain the variable coefficients of hydrodynamic excitations, hydrodynamic reactions and restoring forces. In the article the method is described which takes into consideration the variation of all coefficient in the equations describing the ship oscillatory motion in head, large amplitude incoming wave. When the wave approaches the body, an instantaneous draft is computed, and the draft respective coefficients are interpolated using linear regression method. The equations of non-linear ship oscillation are formulated. The incoming wave is described by the linear theory. To solve the coupled equations of motion in the frequency domain, the trigonometric series method is applied. The comparison of results with experimental values confirms the numerical results.

nonlinear-motion; seakeeping; numerical methods

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