RIASSUNTO
A time-independent finite-difference method is developed to solve for the fully nonlinear waves past floating breakwaters. The numerical model is first verified by comparing the results of wave past submerged breakwater with existing data. The interaction between waves and floating breakwater is studied. The wave reducing effect of various combinations of height and length of breakwater are compared and discussed. The effects of surge and heave motions of floating breakwater are studied. The developed finite-difference method can be easily extended to analyze the problems including coupled surge-heave-pitch motions of floating breakwater and wave-structure interaction. INTRODUCTION The tension leg platform (TLP) has been widely used in ocean engineering, such as floating oil tank, floating airport and aquaculture etc. The TLP can also be used as a floating breakwater to reduce wave height as well as wave forces and then protect coastal bank against assaulting wave. The tension leg floating structure is consist of pre-tensioned wire and floating structure. As the wave action, the floating structure is forced to moving, the motion of the floating structure will generate wave and change the flow field around structure. The new flow field would affect the motion of floating structure that will change the flow field again. The whole process is coupled and the fluid-structure interaction should be considered in studying the real fluid dynamic phenomenon of floating structure under real marine time environment. The related studies have been made as early as 1969, Black et al. studied the scattering of wave passing fixed floating and submerged breakwater. They also discussed the reflection and transition behavior for various water depth and wavelengths. Black and Mei (1971) used Schwinger’s variational formulation and Haskind’s theorem study radiation problem and the effects of heave, sway and roll motions on flow field. Considering surge, heave and pitch motion of floating body,