Ship motions
From Wikipedia, the free encyclopedia
Ship motions are defined by the six degrees of freedom that a ship or boat can experience.
Contents |
[edit] Translation
Heave : is the linear vertical (up/down) motion
Sway : is the linear lateral (side-to-side) motion
Surge : is the linear longitudinal (front/back) motion
[edit] Rotation
Roll : is when the vessel rotates about the longitudinal (front/back) axis.
Pitch : is when the vessel rotates about the transverse (side-to-side) axis.
Yaw : is when the vessel rotates about the vertical (up-down) axis.
[edit] Seakeeping
In ship design it is important to find the behaviour of the ship or floating structure when it is subjected to waves. The behaviour of the ship can be calculated or found through model testing. Calculations can be performed analytically for simple shapes like rectangular barges, but need to be calculated by computer for any realistic shaped ship. The results of these calculations or model tests are transfer functions called Response Amplitude Operators (RAO). For a floation structure they will need to be calculated for all six motions and for all wave headings.
[edit] See also
[edit] References
1) Society of Naval Architects and Marine Engineers (SNAME), "Principles of Naval Architecture", 1989, Vol. III, Pg.41, Section 3 - Ship Responses to Regular Waves.
