'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 May 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

P&I Club warns on Enclosed Space Entry & Testing

The London P&I Club says it continues to see cases of injuries and fatalities associated with entry into enclosed onboard spaces, including cargo holds on bulk

OOCL Renews VOD Training Contract

Videotel, producer and distributor of training videos, 3D animation, and e-Learning courses to the maritime market and part of KVH Industries, Inc., (Nasdaq: KVHI),

Tech & Design Solutions for Modern Workboats

EPA Tier 4 regulations (for engines of 804 hp and higher) and propulsion advancements have many manufacturers and vessel designers changing course to adapt to new requirements and customer demands.

Environmental

First German-Latvian Maritime Forum in Riga

On 19 May, Ziemelblazma Culture Palace in Riga, the Latvian capital was the venue for a meeting between numerous representatives of the Ports of Liepaja, Riga, Ventspils, Lübeck, Kiel and Hamburg.

Trim Optimization – Saving Fuel on Offshore Supply Vessels

A joint development project (JDP) between DNV GL, Statoil and Farstad Shipping has demonstrated that offshore supply vessels (OSV) can save up to 21.000 Euros on their annual fuel bill,

The Impact of Hull Form on Efficiency

There is a growing interest in the fuel efficiency of ships because of fuel prices, climate change and energy security issues. This has resulted in, amongst other things,

News

Strategic Marine Building Luxury Crewboat

Strategic Marine announced the kick-off of its first collaboration with PT. Pelayaran Tanjung Kumawa, expecting to deliver an exclusive luxury crewboat in November this year.

Harding Sold to Palfinger

The PALFINGER Group has signed today the acquisition of 100 per cent of the shares in Herkules Harding Holding AS and thus, the globally operating Harding Group.

First German-Latvian Maritime Forum in Riga

On 19 May, Ziemelblazma Culture Palace in Riga, the Latvian capital was the venue for a meeting between numerous representatives of the Ports of Liepaja, Riga, Ventspils, Lübeck, Kiel and Hamburg.

Marine Equipment

Strategic Marine Building Luxury Crewboat

Strategic Marine announced the kick-off of its first collaboration with PT. Pelayaran Tanjung Kumawa, expecting to deliver an exclusive luxury crewboat in November this year.

Harding Sold to Palfinger

The PALFINGER Group has signed today the acquisition of 100 per cent of the shares in Herkules Harding Holding AS and thus, the globally operating Harding Group.

BigLift Transports Two Siwertell CSU’

Earlier this month, BigLift Shipping’s Happy Dynamic successfully transported two 560 mt Siwertell Continuous Ship Unloaders (CSUs) from Chioggia, Italy, to Liverpool, UK.

 
 
Maritime Careers / Shipboard Positions Maritime Security Maritime Standards Naval Architecture Port Authority Salvage Ship Electronics Ship Repair Sonar Winch
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: 0.1428 sec (7 req/sec)