Propeller Reduces Underwater Radiated Noise
A propeller technology capable of substantially reducing the underwater radiated noise (URN) generated by ships’ propellers has been developed by Oscar Propulsion Ltd. and the University of Strathclyde.
Propeller cavitation can generate as much as 188 dB of URN and can be heard by marine fauna 100 mi. away. According to NOAA, anything above 160 db can pose a significant risk to marine life.
The patented PressurePores system reduces propeller tip vortex cavitation by applying a small number of strategically placed holes in the propeller blades. The addition of these pressure-relieving holes allows ships to operate with a more silent propeller.
Following four years of comprehensive computational fluid dynamics (CFD), modeling and cavitation tunnel tests during the solution’s development phase at Strathclyde, it was demonstrated that PressurePores can reduce cavitation volume by almost 14 percent and URN by up to 10 dB.
Results were further verified in tests on the subcavitating propellers on Princess Royal, a 19-m research catamaran operated by Newcastle University. And, last year, CFD finite element propeller stress tests were successfully completed in accordance with DNV rules.
While Oscar Propulsion’s technology is suitable for all types of vessels, it is ideal for naval vessels, yachts, fishing fleets, offshore vessels and cruise and research ships operating in sensitive environments. The technology can be applied to all types of propellers, including pods and thrusters.