Analysis of the Oscillatory Motions of the Moored Body Scheme A in Waves and Current.
Abstract
This report describes a theoretical investigation of the oscillatory motions, stability, and orientation of the Moored Body Scheme A in current and waves. Linear, first order equations for oscillatory motions and cable tension, are developed for a body of revolution moored to the bottom in finite depth water by a single restraining cable. Wave exciting forces and certain hydrodynamic coefficients are developed from potential flow theory, and non-linear viscous damping effects are included in the formulation by an equivalent linearization technique. Surge, sway, pitch, and yaw motion and tension amplitudes are obtained in response to regular and irregular waves for a variety of water depths, cable lengths, and static cable tensions. Equilibrium orientation in waves and currents is established by the current or wave-current interaction depending on the magnitude of body oscillation velocities relative to the current speed. The most prominent feature of the oscillatory motions is the presence of a pitch resonance occurring at a frequency of 0.33 radians per second. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1977
- Accession Number
- ADA040115
Entities
People
- David W Taylor
- R. Curphey