Hydrodynamic Analysis of Multiple Floating Pontoons With Different Joint Gaps to Waves in Different Water Depth

Abstract

The hydrodynamic analysis of a multiple pontoon-type floating bridge (FB) interacting with oblique waves in water of finite arbitrary depth can be performed, at least in principle, using a general-purpose radiation-diffraction code. The fluid is assumed to be inviscid, and the flow can be considered as incompressible and irrotational, and the velocity potentials are calculated by boundary element method. To study the influences of the water depth and the gap between bodies on the hydrodynamic properties of the pontoons, RAOs (Response Amplitude Operators) of modes of each pontoon versus the wave frequencies are calculated and presented. The results show that the RAOs of pitch modes of different pontoons have differences in high frequency in heading waves, and those RAOs differences of heave of different pontoons in heading and oblique waves are small. Furthermore, all the others results nearly match into one. The influences of width of the gap between pontoons to RAOs are small, but the water depth has obvious influence on RAOs. In addition, the motions of FB are simulated and compared in different sea conditions which are represented by the JONSWAP spectrum. The results show that not only the peak wave periods but also the significant wave heights have obvious influences on the motions of the FB.