Nonlinear analysis of submerged ocean buoy systems

A single-point, taut-line mooring suspended by a submerged spherical buoy, of the type used to support oceanographic instrumentation, is investigated. The forcing function is composed of a steady-state horizontal current and a surface wave approximated by first order (Airy) theory. Buoy system nonlinearities are manifested by profile drag effects proportional to the square of the velocity and by the nonlinear elastic properties of the synthetic cable. An explicit numerical solution technique using a digital computer was made to obtain cable tension and shape, and buoy motion. The technique was applied to the response analyses of a U.S. Navy bottom-moored instrument system (BOMIS).