Hydrodynamic Coefficients And Motions Due To A Floating Cylinder In Waves

Abstract

Hydrodynamic coefficients and responses due to surge, heave and pitch motions induced by wave excitation for a floating vertical circular cylinder in water of finite depth are formulated in this paper. Both the combined effects of scattering and radiation are considered in evaluating the total velocity potential. The total velocity potential is decomposed as the linear combination of four velocity potentials; one due to scattering in the presence of an incident wave on fixed structure (diffraction problem), and the other three due to radiation respectively by surge, heave and pitch motion on calm water (radiation problem). For each case, the velocity potential is derived by considering two regions, namely, interior region and exterior region. The complex matrix equations are solved numerically to determine the unknown coefficients which are used to compute the hydrodynamic quantities. Numerical results of hydrodynamic coefficients and the motions due to surge, heave and pitch are presented in graphical forms for different depth to radius and draft to radius ratios. The total forces due to the combined effects of diffraction and radiation are also derived and presented in graphical forms for different wave parameters.