PROPELLER EXCITED VIBRATORY FORCES FOR NS SAVANNAH DERIVED FROM MODEL WAKE SURVEY
Propeller forces and moments induced by the nonuniform inflow velocities into the propeller plane of the N.S. Savannah are calculated from a wake survey conducted on a model of the ship at a displacement corresponding to 16,200 tons and at a speed corresponding to 20.5 knots. A harmonic analysis of the wake was made for the longitudinal and tangential velocity component ratios. The analysis indicated that the seventh harmonic (seven blades) has the smallest relative harmonic amplitude. The magnitude of the thrust fluctuation in percentage of the mean thrust amounted to 18.0 percent double amplitude D.A. at 20.5 knots. The torque fluctuation in percentage of the mean torque amounted to about 15 percent D.A. at the same speed. The eccentricity factor e/D is close to those of other surface ships.
- This document is available for review at the Department of Commerce Library, Main Commerce Building, Washington, D.C., under reference number DTMB-LTR-962.
David Taylor Model BasinDepartment of the Navy
Washington, DC United States
- Hinterthan, W B
- Publication Date: 1964-9-9
- Features: Figures; References; Tables;
- Pagination: 35 p.
- TRT Terms: Force; Nuclear powered ships; Propellers; Vibration; Wakes
- Old TRIS Terms: Harmonic analysis; Propeller forces; Vibration research; Wake surveys
- Subject Areas: Marine Transportation; Vehicles and Equipment;
- Accession Number: 00026631
- Record Type: Publication
- Source Agency: Maritime Administration
- Files: TRIS, USDOT
- Created Date: Feb 14 1973 12:00AM