air lubrication TOOLS AND FACILITIES
MARIN can also be your research partner in the development of an air lubrication system, or perform an independent evaluation of the present system used on your ship.
For this we have several tools and facilities available.Full-scale measurements
MARIN has the equipment and experience to accurately measure the required speed-power relation to determine the effect of air lubrication systems. In addition we can determine the presence of either an air layer, a water layer or bubbly flow beneath a ship, by means of measurement probes developed in-house.Model tests
MARIN has already tested several systems on model scale and thus built up experience in testing and extrapolating model test results. During the tests the airflow rate can be optimised, the performance is accurately measured and air layers can be observed by means of (high-speed) underwater cameras. However, scaling the model test results can be challenging depending on the type of air lubrication. Model tests can be performed in MARIN’s Shallow Water Basin or Deep Water Basin.CFD computations
CFD computations for air lubrication systems is still work in progress and not yet available. However, steps are being made and we hope to share our research soon. Is it clear that CFD computations can be helpful in determining the additional resistance of an air lubrication system when turned off, or in providing information for the correct positioning of the air inlets. For this we use our in-house developed RANS code ReFRESCO.References
- Elbing, Brian R, Eric S Winkel, Keary A Lay, Steven L Ceccio, David R Dowling, and Marc Perlin. 2008. “Bubble-Induced Skin-Friction Drag Reduction and the Abrupt Transition to Air-Layer Drag Reduction.” Journal of Fluid Mechanics 612: 201–36. https://doi.org/10.1017/S0022112008003029.
- Rotte, Gem, Oleksandr Zverkhovskyi, Maarten Kerkvliet, and Tom van Terwisga. 2016. “On the Physical Mechanisms for the Numerical Modelling of Flows Around Air Lubricated Ships.”
- SANDERS, WENDY C., ERIC S. WINKEL, DAVID R. DOWLING, MARC PERLIN, and STEVEN L. CECCIO. 2006. “Bubble Friction Drag Reduction in a High-Reynolds-Number Flat-Plate Turbulent Boundary Layer.” Journal of Fluid Mechanics 552 (1): 353. https://doi.org/10.1017/S0022112006008688.
- Zverkhovskyi, O, T Van Terwisga, M Gunsing, J Westerweel, and R Delfos. 2014. “Experimental Study on Drag Reduction by Air Cavities on a Ship Model.” In 30th Symposium on Naval Hydrodynamics, 9. Hobart, Tasmania, Australia.