'Singing' Propellers Phenomenon Controlled

By Joseph R. Fonseca
Saturday, March 05, 2016
Singing Propeller - Wärtsilä and City University London have in a joint research project succeeded in identifying the specific design parameters that create the risk of 'singing' propellers. Photo Wartsila

A joint research project carried out by Wärtsilä and City University London has succeeded in identifying the specific design parameters that create the risk of 'singing' propellers. Though rare, 'singing' is nevertheless an annoying problem that occurs as a strong tonal noise originating from the propeller, thus causing a negative effect to onboard comfort levels. The research programme reached its conclusions in December 2015.

The problem has long been recognised in the marine industry. While the general perception has been that the frequency of the propeller blades' vibration mode coincides with the frequency of the hydrodynamic excitation forces at the trailing edge of the blades, the current research indicates that there is more complexity and sensitiveness to this hypothesis.

"Our research has shown that the 'singing' phenomenon can be controlled by selecting the proper main parameters of the propeller blades, by careful attention to the flexural modes of the propeller blades, and by careful attention to the specific geometry at the trailing edge of the blades. It has shown that all these aspects are interacting and can prevent the 'singing' of propellers," says Arto Lehtinen, Vice President, Propulsion, Wärtsilä Marine Solutions.

Finite Element Method (FEM) analysis tools have been used in the identifying of the risk indicators related to the main propeller design parameters. By correctly adjusting these parameters, the response side risks can be minimised. Similarly, Computational Fluid Dynamic (CFD) technology was used to analyse the vortex shedding behaviour of the trailing edge design. The results indicate that a proper design of the trailing edge details reduces the shedding and, therefore, also the excitation forces. Wärtsilä has used CFD in its hydrodynamic design processes for some 20 years.

Vessels at risk for 'singing' are identified in the design process. Along with the existing Wärtsilä propeller design features, notably optimum efficiency, strength, and limited cavitation and pressure pulses, the avoidance of 'singing' has now been added as a standard Wärtsilä design feature. Furthermore, the findings from the research project have been incorporated into the company's OPTI-Design, which was introduced as a new state-of-the-art design concept in 2014. That design offers fuel savings of up to 4 per cent and highly reliable full scale performance predictions.
 

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter July 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

Wärtsilä REvolution system takes sealing technology to New Level

The new Wärtsilä REvolution system is a digital management system that controls, monitors, records and analyses the performance of seals autonomously in real time,

Fuel Consumption, Emissions Monitoring Software Updated

As part of the ongoing Blue Star Delos Renewable Energy Innovation Project, Eco Marine Power (EMP) stated that the Aquarius Management & Automation System (MAS)

MSC Invests in TRAXENS Container Monitoring

MSC Mediterranean Shipping Company has reached an agreement to back French start-up TRAXENS, a developer of cargo logistics solutions and creator of a container monitoring and coordination system.

Environmental

Wärtsilä REvolution system takes sealing technology to New Level

The new Wärtsilä REvolution system is a digital management system that controls, monitors, records and analyses the performance of seals autonomously in real time,

Damen Fishery Research Vessel for Angola

The Damen Shipyards Group has received an order for a state-of-the-art, 74 m Fishery Research Vessel from the Angolan Ministry of Fisheries. This special vessel,

Fuel Consumption, Emissions Monitoring Software Updated

As part of the ongoing Blue Star Delos Renewable Energy Innovation Project, Eco Marine Power (EMP) stated that the Aquarius Management & Automation System (MAS)

Naval Architecture

Damen Fishery Research Vessel for Angola

The Damen Shipyards Group has received an order for a state-of-the-art, 74 m Fishery Research Vessel from the Angolan Ministry of Fisheries. This special vessel,

First VectRA 3000 Tug Delivered

Sanmar’s first VSP (Voith Schneider Propeller) tug, of the new VectRA 3000 series, named Arie A has been constructed for Italian operator Tripmare Spa of Trieste.

C. Raymond Hunt Associates Celebrates 50 Years

C. Raymond Hunt Associates, a boat design firm that continues to expand on the legacy of its founder, C. Raymond Hunt, to produce innovative boats with rugged seaworthiness,

News

Bahri Q2 Net Profit Soars

National Shipping Company of Saudi Arabia (Bahri), the exclusive oil-shipper for Saudi Aramco, reported a 47.2 percent increase in second-quarter net profit on Tuesday.

DP World's H1 Volumes Rise

Ports operator DP World reported on Tuesday first-half 2016 gross container volumes up 1.2 percent on a like-for-like basis and up 2.5 percent on a reported basis.

Broad Declines drag Baltic Index down

The Baltic Exchange's main sea freight index, tracking rates for ships carrying dry bulk commodities, fell on Tuesday on lower rates for capesize, panamax and supramax vessels.

Marine Equipment

Ecofix Filler Coat Cuts Rudder Repairs Cost

With an increasing trend for thruster and rudder manufacturers finishing their products with self-cleaning protective hard coatings, Antwerp headquartered Subsea

Wärtsilä REvolution system takes sealing technology to New Level

The new Wärtsilä REvolution system is a digital management system that controls, monitors, records and analyses the performance of seals autonomously in real time,

MOL Makes Fleet-wide Migration to Fleet Xpress

Fleet Xpress will deliver data intelligence to drive smarter and greener shipping operations   26 July 2016: Inmarsat (LSE:ISAT.L), the leading provider of global

 
 
Maritime Careers / Shipboard Positions Maritime Standards Naval Architecture Pipelines Pod Propulsion Port Authority Salvage Ship Repair Ship Simulators Shipbuilding / Vessel Construction
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1508 sec (7 req/sec)