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.
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, often in combination with observations 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.
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, often in combination with observations 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:
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.
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
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)
(complete overview of papers can be found under Publications)
The partial cavity on a 2D foil revisited
Hoekstra, M. and Vaz, G., CAV2009, 2009
Modeling and analysis of a cavitating vortex in 2D unsteady viscous flow
Bosschers, J. , CAV2009 7th International Symposium on Cavitation, 2009
Computation of hull-pressure fluctuations due to non-cavitating propellers
Lafeber, F.H., Wijngaarden, H.C.J. van and Bosschers, J., SMP 1st International Symposium on Marine Propulsors , 2009
Investigation of hull pressure fluctuations generated by cavitating vortices
Bosschers, J., SMP 1st International Symposium on Marine Propulsors, 2009
Investigation of the resonance frequency of a cavitating vortex
Bosschers, J., NAG-DAGA International Conference on Acoustics, 2009
Hoekstra, M. and Vaz, G., CAV2009, 2009
Modeling and analysis of a cavitating vortex in 2D unsteady viscous flow
Bosschers, J. , CAV2009 7th International Symposium on Cavitation, 2009
Computation of hull-pressure fluctuations due to non-cavitating propellers
Lafeber, F.H., Wijngaarden, H.C.J. van and Bosschers, J., SMP 1st International Symposium on Marine Propulsors , 2009
Investigation of hull pressure fluctuations generated by cavitating vortices
Bosschers, J., SMP 1st International Symposium on Marine Propulsors, 2009
Investigation of the resonance frequency of a cavitating vortex
Bosschers, J., NAG-DAGA International Conference on Acoustics, 2009
Most recent noise and vibration related articles written for MARIN Report:
(complete overview of articles can be found under Publications)
(complete overview of articles can be found under Publications)
Measuring success
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
New borescope technology
Ivo van der Hout, MARIN report, 2009
Surface Ship Radiated Flow Noise project completed
Johan Bosschers & Bert Koops, MARIN Report, 2009
Dynamic loads on pods
Gerco Hagesteijn & Martijn van Rijsbergen, MARIN Report, 2009
MARIN Report, 2009
Oasis of the Seas
Giedo Loeff, Jaap van Heerd & Reint Dallinga, MARIN report, 2009
New borescope technology
Ivo van der Hout, MARIN report, 2009
Surface Ship Radiated Flow Noise project completed
Johan Bosschers & Bert Koops, MARIN Report, 2009
Dynamic loads on pods
Gerco Hagesteijn & Martijn van Rijsbergen, MARIN Report, 2009
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
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