Abstract
In the previous report, experiments and calculations showed that viscous drag forces acting on a cold water pipe and mooring chains had a great effect on a pitching motion of an OTEC platform in regular waves at its resonant period. The theoretical consideration suggested that these forces affect also on surging and heaving motion at their resonant periods, but this fact could not be confirmed experimentally in regular waves because of their very long resonant periods. In this paper, we research on the effects of these forces on surging and heaving motion experimentally and theoretically in irregular waves. Forces acting on a cold water pipe and mooring chains are nonlinear ones. A method of a computer simulation for the nonlinear motions and forces are proposed in this study.
