General information
Cavitation is the transition of liquid water to vapour in low pressure areas. Cavitation develops spontaneously when the local pressure in a fluid drops below the saturated vapour pressure of water. This phenomenon is in fact the boiling of water at room temperature, not by heat but by reducing the pressure. Cavitation bubbles of varying size collapse fiercely when entering a area of higher pressure. The collapse of the cavitation bubbles causes high-pressure shockwaves in the fluid. Periodic fluctuations of the pressure field as caused by the dynamics of the cavitation on the rotating propeller blades excite the ship hull, a feature which can cause vibration and noise. Under certain conditions cavitation can also cause material erosion.
Cavitation is the transition of liquid water to vapour in low pressure areas. Cavitation develops spontaneously when the local pressure in a fluid drops below the saturated vapour pressure of water. This phenomenon is in fact the boiling of water at room temperature, not by heat but by reducing the pressure. Cavitation bubbles of varying size collapse fiercely when entering a area of higher pressure. The collapse of the cavitation bubbles causes high-pressure shockwaves in the fluid. Periodic fluctuations of the pressure field as caused by the dynamics of the cavitation on the rotating propeller blades excite the ship hull, a feature which can cause vibration and noise. Under certain conditions cavitation can also cause material erosion.
Services & Activities
The Propulsors and Cavitation Knowledge Team of MARIN offers its expertise on a wide range of cavitation related topics. Most common are the evaluation of propeller designs on cavitation related pressure fluctuations to prevent ship vibration problems and the assessment of the risk of cavitation erosion.
In its history MARIN has tested a vast number of propellers now contained in its stock of models. For ships such as ferries and cruise liners for which comfort aspects are essential MARIN assists their customers in meeting strict design requirements of today. For naval applications MARIN offers their experience in designing low-noise propellers. These propellers have a delayed inception of cavitation as caviation is a primary noise source. For propellers of merchant ships a compromise between the propulsive efficiency and cavitation hinderance is aimed for from the early start of the design. Verification of the cavitation performance by model experiments is often requested by ship owners.
The Propulsors and Cavitation Knowledge Team of MARIN offers its expertise on a wide range of cavitation related topics. Most common are the evaluation of propeller designs on cavitation related pressure fluctuations to prevent ship vibration problems and the assessment of the risk of cavitation erosion.
In its history MARIN has tested a vast number of propellers now contained in its stock of models. For ships such as ferries and cruise liners for which comfort aspects are essential MARIN assists their customers in meeting strict design requirements of today. For naval applications MARIN offers their experience in designing low-noise propellers. These propellers have a delayed inception of cavitation as caviation is a primary noise source. For propellers of merchant ships a compromise between the propulsive efficiency and cavitation hinderance is aimed for from the early start of the design. Verification of the cavitation performance by model experiments is often requested by ship owners.
Facilities & Tools
Cavitation investigations are carried out in the following MARIN facilities:
Cavitation investigations are carried out in the following MARIN facilities:
- Depressurised Towing Tank (DTT): Cavitation observation and measurements of the pressure fluctuations on the hull above the cavitating propellers at a ship model
- Cavitation Tunnel (CT): Cavitation research involving dedicated test set-ups that are not feasible in the DTT.
For cavitation related issues a large number of experience based tools and CFD programs (such as ReFRESCO, which developments started to enable the calculation of cavitation in viscous-flows) are available.
The main tools used are:
The main tools used are:
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
The list below gives a review of cavitations projects carried out at MARIN:
The list below gives a review of cavitations projects carried out at MARIN:
- TIPVOR (RNN/US) 1996-2000
- AFDEASR 1990
The following Joint Industry Projects (JIPs) were focussed on cavitation:
- CoCa (2000-2003)
Most recent cavitation related papers presented by MARIN
(complete overview of papers can be found under Publications)
(complete overview of papers can be found under Publications)
Exploratory RANS Simulations Of Partial Cavitation And Its Dynamics
Hoekstra, M., IV International Conference on Computational Methods in Marine Engineering (ECCOMAS MARINE), Lisbon, Portugal, 2011
The myth of the re-entrant jet
Hoekstra, M., WIMRC 3rd International Cavitation Forum, UK, 2011
The influence of the wake scale effect on the prediction of hull pressures due to cavitating propellers
Schuiling, B., Lafeber, F.H., Ploeg, A. van der, and Wijngaarden, H.C.J. van, SMP 2nd International Symposium on Marine Propulsors, Hamburg, Germany, 2011
On Predicting Cavitation-Induced Hull Pressure Fluctuations - Wake Scale Effects And Signal Variability
Wijngaarden, H.C.J. van, Bosschers, J. and Terwisga, T.J.C. van, IMarEST Ship Noise and Vibration Conference, London, 2010
On the influence of viscous effects on 2-D cavitating vortices
Bosschers, J. , 9th International Conference on Hydrodynamics, Shanghai, China, 2010
Hoekstra, M., IV International Conference on Computational Methods in Marine Engineering (ECCOMAS MARINE), Lisbon, Portugal, 2011
The myth of the re-entrant jet
Hoekstra, M., WIMRC 3rd International Cavitation Forum, UK, 2011
The influence of the wake scale effect on the prediction of hull pressures due to cavitating propellers
Schuiling, B., Lafeber, F.H., Ploeg, A. van der, and Wijngaarden, H.C.J. van, SMP 2nd International Symposium on Marine Propulsors, Hamburg, Germany, 2011
On Predicting Cavitation-Induced Hull Pressure Fluctuations - Wake Scale Effects And Signal Variability
Wijngaarden, H.C.J. van, Bosschers, J. and Terwisga, T.J.C. van, IMarEST Ship Noise and Vibration Conference, London, 2010
On the influence of viscous effects on 2-D cavitating vortices
Bosschers, J. , 9th International Conference on Hydrodynamics, Shanghai, China, 2010
Most recent cavitation related articles written for MARIN Report:
(complete overview of articles can be found under Publications)
(complete overview of articles can be found under Publications)
MARIN set to open its new Depressurised Wave Basin
MARIN Report, 2011
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
High speed Cavitation Observation through a 12 mm hole
Ivo van der Hout, MARIN Report, 2007
MARIN Report, 2011
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
High speed Cavitation Observation through a 12 mm hole
Ivo van der Hout, MARIN Report, 2007
Contact
For more information on how MARIN can help your organisation with the issue of cavitation, please contact the Propulsors and Cavitation Knowledge Team at: propulsors@marin.nl
For more information on how MARIN can help your organisation with the issue of cavitation, please contact the Propulsors and Cavitation Knowledge Team at: propulsors@marin.nl