Air lubrication company Silverstream has drawn attention to an academc study that suggests hull lubrication can have a significant positive effect on underwater radiated noise (URN), as well as reducing friction and thus saving fuel and emissions.
Prof John Carlton – a fellow of the Royal Academy of Engineering, and Professor of Marine Engineering and Director of Maritime Studies at City University of London – has published a new whitepaper analysing the impact of hull air lubrication on (URN), propulsion and cavitation.
Focusing on URN, which has been, and continues to be, a key sustainability issue for the IMO, the whitepaper finds that: “the presence of air in the form of an air bubble- mixture around the hull, for example as generated by an air lubrication system, will significantly attenuate the transmission of noise from the ship into the sea environment.”
Silverstream interprets the whitepaper’s findings to show that the Silverstream System reduces URN emissions from the hull because the air bubbles reflect acoustic energy. Relatively little sound will penetrate a curtain of air bubbles, making them very efficient at masking noise as well as their friction-reducing properties.
