Record Details
Field | Value |
---|---|
Title | Dynamics of single point ocean moorings of a buoy : a numerical model for solution by computer |
Names |
Nath, John H.
(creator) |
Date Issued | 1969-07 (iso8601) |
Abstract | A numerical model was developed which predicts the dynamic response of a single mooring line and a buoy of forty feet diameter to sinusoidal waves, wind and current in all deep waters. All forces and reactions were considered to be in one plane. The basic equations for the mooring line motion were obtained by considering a small element of the line in terms of the conservation of momentum and mass and the continuity of the line filament. The resulting partial differential equations were numerically integrated by first a transformation followed by application of the method of characteristics. A non-linear stress-strain diagram was used. The boundary conditions were that no motion occurred at the anchor except rotations and the motion of the upper end of the line was the same as the motion of the attachment point of the buoy. The buoy was considered to be a rigid body and accelerations were determined from Newton's second law of motion. Recurrence formulas determined displacements and velocities. A comparison with some prototype information was made. Transfer functions between wave spectra and line tension spectra were available for a mooring in 13, 000 feet of water near Bermuda. The same transfer functions were developed with the numerical model and good agreement was achieved. Frequency response curves for the moored buoy in pitch and heave were also obtained and the results show that one dimensional wave spectra obtained by double integration of the vertical acceleration of the buoy are valid. |
Genre | Technical Report |
Topic | Oceanographic buoys |
Identifier | http://hdl.handle.net/1957/8451 |