A TIME DOMAIN SOLUTION TO THE MOTIONS OF A STEERED SHIP IN WAVES
The problem of ship motions in waves is formulated in the time domain by means of a convolution integral which relates the ship motion response to arbitrary exciting forces, under assumption that the response is linear. The convolution integral is evaluated numerically to obtain the ship motions at discrete intervals of time. Frequency independent nonlinearities of arbitrary form are incorporated into the model by considering them as part of the arbitrary exciting forces. Nonlinearities with time lag, such as those arising from rudder motions, are particularly amenable to this treatment. Nonlinearities that are functions of the instantaneous motions of the ship are approximated by continuously extrapolating the ship motions. Thus one is able to include frequency-dependent linear force terms in what amounts to a stepwise solution of the nonlinear equation of motion, a capability not available in the conventional direct numerical integration techniques exemplified by, e.g., Runge-Kutta. (Author)
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Corporate Authors:
University of California, Berkeley
Institute of Transportation Studies Library
Berkeley, CA United States 94720 -
Authors:
- Perez y Perez, L
- Publication Date: 1972-11
Media Info
- Pagination: 73 p.
Subject/Index Terms
- TRT Terms: Analysis; Automatic pilot (Aircraft); Force; Hydrodynamic pressure; Information processing; Maneuverability; Numerical analysis; Ocean waves; Oscillation; Pitch (Dynamics); Rolling; Rudders; Ship motion; Ships; Steering
- Uncontrolled Terms: Computer aided analysis
- Old TRIS Terms: Cg; Force mechanics; Hydrodynamic forces; Marine rudders; Roll; Rudder oscillation; Sea states; Steering characteristics
- Subject Areas: Marine Transportation; Vehicles and Equipment;
Filing Info
- Accession Number: 00051728
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: Intrm Rpt
- Contract Numbers: DOT-CG-84,549-A
- Files: TRIS
- Created Date: Mar 25 1974 12:00AM