ON THE EFFECT OF FREQUENCY DEPENDENCY OF THE STABILITY DERIVATIVES UPON STEERING MOTIONS
(1) Only values of stability-derivatives in a low frequency range contribute to the calculated value of ship yaw response to rudder movements. Such "significant frequency range" varies with the time passed since the rudder execution at which the ship response is to be calculated, and the longer the time, the narrower the significant frequency range. (2) For ordinary patterns of rudder movements such as stepwise or trapezoidal rudder movements, the above mentioned frequency range is so narrow that for this range the values of the derivatives almost stay constant and are approximately equal to the values at zero frequency. Therefore, constant values of derivatives corresponding to zero frequency can be used in calculating ship response to ordinary pattern of rudder motions without causing significant errors. (3) In calculating yaw amplitude in waves, it will be more appropriate to use derivatives corresponding to the proper encounter frequency than to use zero-frequency derivatives.
- Paper presented at the 14th International Towing Tank Conference, 1975.
National Research Council of Canada1200 Montreal Road
Ottawa, Ontario Canada K1A 0R6
- Fujino, M
- Motora, S
- Publication Date: 1975
- Pagination: n.p.
- TRT Terms: Force; Rudders; Ship motion; Stability (Mechanics); Steering; Yaw; Yaw
- Old TRIS Terms: Rudder forces; Ship response; Stability derivatives; Steering dynamics
- Subject Areas: Marine Transportation; Vehicles and Equipment;
- Accession Number: 00323588
- Record Type: Publication
- Source Agency: Stevens Institute of Technology
- Report/Paper Numbers: Proceeding
- Files: TRIS
- Created Date: Nov 19 1980 12:00AM