Noise & vibrations
noise and vibration
General information
One of the adverse effects of propeller cavitation is that it causes noise and vibration on board. Fluctuating propeller forces may be transferred to the structure through the shaft and bearings. Often more important is the water-borne excitation of the plating above the propeller as a result of pressure pulses generated by the growth and collapse of cavities on or in the vicinity of propeller blades.

Services & Activities
The prediction of vibratory excitation forces that are induced by the cavitating propeller is one of the services delivered by the Propulsors and Cavitation Knowledge Team. Both experimental and computational means are used to assist the client in judging the propeller design with respect to cavitation performance and its effect on vibratory excitation forces.

The Trials and Monitoring Department performs measurements of propeller-induced hull-pressures on board ships (PDF), often in combination with observations (PDF) of the cavitation phenomena through holes in the aftbody plating. Also Finite Element Analyses are performed on the measured excitation forces.

Both departments join forces in advising the client with respect to possible measures that can be taken to alleviate noise and vibration problems.

Facilities & Tools
Hull-pressure fluctuation measurements are conducted to predict propeller excitation forces. MARIN has two facilities designed for such cavitation-related work:

  • Depressurized Towing Tank: Propeller cavitation and hull-pressure measurements made on the same, large ship model as used for powering performance testing
  • Cavitation Tunnel: Same type of testing using so-called “dummy” models with realistic afterbody geometry
In the propeller/ship design phase also computational tools are used for noise and vibration related issues:

  • PROCAL: Panel code for propellers and cavitation
  • EXCALIBUR: Panel code for noise diffraction around ships
  • ANSYS: code for finite element analyses (for onboard analyse of trails)
  • ARTEMIS: code for modal analyses (for onboard analyse of trails)
Software Sales
Some software tools are available for commercial use outside MARIN. A complete overview of these software tools for sale can be found under Software Sales.

Experience
More than 100 projects since the opening of the Depressurized Towing Tank in 1974 were focussed on the noise and vibration issue, ranging from QE2 tot QM2

The following Joint Industry Projects (JIPs) were focussed on the noise and vibration issue, and especially on propeller-induced vibratory excitation forces:

  • COCA (COrrelation of Cavitation)
  • CAVDISC (CAVitation DISComfort, CRSWorking Group)
Most recent noise and vibration related papers presented by MARIN
(complete overview of papers can be found under Publications)

A Semi-Empirical Method to Predict Broadband Hull Pressure Fluctuations and Underwater Radiated Noise by Cavitating Tip Vortices
Bosschers, J., Fifth International Symposium on Marine Propulsors (SMP), Espoo, Finland, 2017

Suppression Of underwater Noise Induced by Cavitation: SONIC
Prins, H.J., Flikkema, M.B., Bosschers, J., Koldenhof, Y., Jong, C.A.F. de, Pestelli, C., Mumm, H., Bretschneider, H., Humphrey, V., Hyensjö, M., 6th European Transport Research Conference, Warsaw, Poland, 2016

Using the FW-H equation for hydroacoustics of propellers
Lloyd, T.P., Lidtke, A.K., Rijpkema, D.R., Wijngaarden, H.C.J. van, Turnock, S.R. and Humphrey, V.F., 18th Numerical Towing Tank Symposium (NuTTS), Cortona, Italy, 2015

Implementing The Ffowcs Williams-Hawkings Acoustic Analogy Into A Viscous CFD Solver
Lloyd, T., Rijpkema, D., van Wijngaarden, E., NUTTS 2014, Gothenburg, Sweden., 2014

Underwater radiated noise measurements with a silent towing carriage in the Depressurized Wave Basin
Bosschers, J., Lafeber, F.H., de Boer, J., Bosman, R. and Bouvy, A., 3rd International Conference on Advanced Model Measurement Technology for the EU Maritime Industry (AMT), Gdansk, Poland , 2013

Most recent noise and vibration related articles written for MARIN Report:
(complete overview of articles can be found under Publications)

Supporting silent ships: measuring underwater radiated noise from cavitating ship propellers
Frans Hendrik Lafeber, Thomas Lloyd & Johan Bosschers, MARIN Report, 2017

6-component propeller blade/shaft balance provides important insight
René Bosman & Do Ligtelijn, MARIN Report, 2017

Observing cavitation for naval applications
Ingo Drummen, MARIN Report, 2017

Accurate predictions for noise levels of cavitating propellers now possible
Frans Hendrik Lafeber, Johan Bosschers & Yvonne Koldenhof, MARIN Report, 2016

Success of renowned ‘Wageningen B’ followed by the future-ready C & D-Series
MARIN Report, 2015

Contact
For more information on how MARIN can help your organisation with the issue of noise and vibration, please contact the Propulsors and Cavitation Knowledge Team at: propulsors@marin.nl for experiments and computations in propeller/ship design.

For measurements on board and FEM computations, contact the Trials and Monitoring Department

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