The patented Oscar PressurePores system reduces propeller tip vortex cavitation by applying a small number of strategically bored holes in the propeller blades.
In partnership with University of Strathclyde, researchers used computational fluid dynamics (CFD) modeling and cavitation tunnel tests, to demonstrate that the PressurePores system can reduce cavitation volume by almost 14 percent and underwater radiated noise (URN) by up to 21dB.
“It’s not a case of simply drilling holes into the blades, as this will affect the propeller’s thrust capability. CFD modeling at Strathclyde allows us to know exactly where to place the holes for maximum efficiency and optimum noise reduction.” said David Taylor, CEO, Oscar Propulsion.
Professor Mehmet Atlar, the Research Director of the Department of Naval Architecture, Ocean and Marine Engineering at the University of Strathclyde, said: “For a ship with non-cavitating propellers, the dominant URN is associated with the hull and propeller flow, as well as the ship’s machinery and electrical sources. As soon as the propeller incepts cavitation, the dominant source becomes propeller cavitation, whilst these other sources still contribute. As a result, a series of periodic tones at discrete blade rate (low) frequencies and its multiples, takes place. This is accompanied by a spectrum of broadband (high) frequency noise due to cavitation and its complex dynamics”.
Taylor furthered: “PressurePores has a major mitigating effect on propeller cavitation and URN and can be incorporated into new propellers or can be retrofitted to existing propellers either in drydock or possibly in-water. While PressurePores are suitable for all types of vessel, they are particularly suitable for naval vessels, fishing fleets, offshore vessels and cruise ships operating in sensitive environments. The technology can be applied to all types of propellers, including pods and thrusters.”
Oscar Propulsion is now looking to partner with shipping companies and propeller designers or manufacturers to commercialize the PressurePores concept and to help the shipping industry operate in an environmentally safer way.