EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF TETHERED SPAR AND SPHERE BUOYS IN IRREGULAR WAVES

A series of large-scale experiments were conducted to examine the motions of buoys in a variety of wave climates. In conjunction with these experiments, numerical simulations of selected tests were conducted to test the present ability of a particular computer program to model buoy responses. This paper considers individual wave tests for two of the buoy models used in the experiments, a spar buoy and a sphere buoy. The wave field is generated using a JONSWAP spectrum. A description of the experiments shows that each buoy is subject to. significant resonant responses, in heave for the spar and surge for the sphere, even though wave forcing is not present at or immediately adjacent to the resonant frequencies. The numerical simulations show generally good comparisons with the experimental data.