A NEW DIMENSION TO SHIP PROPULSION TEST TECHNIQUES
Cavitation tunnel No 2 at the Swedish State Shipbuilding Experimental Tank, SSPA, and the depressurized towing tank at the Netherlands Ship Model Basin, NSMB, are two test facilities especially designed for investigating cavitation and propeller induced vibratory forces. The paper describes comparative tests in these facilities, carried out with models of a 300,000 TDW tanker in full load and ballast conditions. First, results of resistance and propulsion tests, open water tests and wake measurements are presented and discussed. The full scale wake pattern predicted with a method developed at NSMB is compared with the wake predicted with the SSPA extrapolation method. Further, diagrams illustrate how the propeller cavitation and the vibratory pressures on the hull are increased with the decreasing cavitation number and increasing propeller load. It is shown that there is a correlation between cavitation extension and the amplitude and the phase angle of the first harmonic component of the pressure signal. Different methods of analysing a pressure signal with time-dependent amplitude are discussed and a hypothesis is put forward that the maximum and not the mean amplitudes should be used when predicting the full scale pressure fluctuations.
- Presented at the Spring meeting, Philadelphia, PA. of SNAME.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ United States 07306-2907
- van Manen, J D
- Oosterveld, MWC
- Publication Date: 1976-6
- Features: References;
- Pagination: 21 p.
- TRT Terms: Cavitation (Mechanics); Cavitation erosion; Open water tests; Propellers; Vibration; Wakes
- Old TRIS Terms: Propeller induced vibration; Wake measurement
- Subject Areas: Design; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00132734
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Report/Paper Numbers: Paper No. 10
- Files: TRIS
- Created Date: May 14 1976 12:00AM