Large angular motions of tethered surface buoys

✍ Scribed by J.W. Leonard; K. Idris; S.C.S. Yim

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 955 KB
• Volume: 27
• Category: Article
• ISSN: 0029-8018
• DOI: 10.1016/s0029-8018(99)00046-3

✦ Synopsis

A three-dimensional coupled analysis of the interaction of a floating buoy and its mooring is studied. External loads include hydrodynamic forces, tether tensions, wind loads and system weight and buoyancy. Nonlinearities include large rotational and translational motions and non-conservative fluid loads. The mooring problem is formulated as a nonlinear two-pointboundary-value-problem. At each instant in time, the mooring problem is solved by direct integration using a successive iterative algorithm to satisfy boundary conditions. Buoy kinetic and kinematic equations are derived assuming large angles represented by Euler parameters. Coupling between the buoy and the mooring is enforced by matching the velocities of the tether and buoy at the attachment point. A predictor-corrector coupling algorithm is used with multiple sizes of time steps used to provide stability for the separate mooring and buoy models. Numerical results are compared to experimental responses of three types of buoys (sphere, spar and disc) subject to both regular and irregular waves.