Testing Breaking Waves vs. Offshore Wind Turbines

Tuesday, November 16, 2010

More than 60 representatives of the international offshore wind industry gathered last week at the Offshore Wind Seminar, organized by the Maritime Research Institute Netherlands (MARIN) and the Energy research Centre of the Netherlands (ECN). This seminar included a visit to unique model tests in the MARIN facilities of breaking waves against an offshore wind turbine. This pilot series of model tests, with a special model of an offshore wind turbine with realistic flexibility, was completed and confirmed that breaking waves can induced significant oscillations and accelerations in the turbine.

Dr. Bas Buchner, Vice President of MARIN and leader of its Renewable ENergy Team (RENT), said, “MARIN wants to contribute to the development of reliable offshore renewable energy with this expertise from the maritime industry. Breaking waves can occur quite often in the shallow water areas of fixed wind turbines. Considering the relatively flexible foundations and towers of offshore wind turbines, we realized that the impulsive loading of breaking waves might result in resonant vibrations of the structure. This can have significant effects on the loads in the tower and accelerations in the critical mechanical systems at nacelle level . But we did not want to state this as a problem without a confirmation, so we developed these pilot model tests within our own R&D.”

For this purpose a special model was developed by MARIN’s specialists in the field of hydrodynamic loading and structural response. The model material and set-up was chosen such that the model had the correct flexibility and natural periods, a technique recently developed to investigate the vibrations of ships in extreme waves.

The initial results of the tests confirm that the tower can vibrate due to the breaking waves. Erik-Jan de Ridder, the responsible MARIN Project Manager, said, “When a large wave hit the foundation and tower, the tower started to vibrate at its natural periods. At nacelle level this resulted in large horizontal accelerations, in one case even up to 0.5g (5m/s2). Although these results need further analysis, the first observation is that these values are large and will impact the design and operation of the turbine.”

The test results will now be further analyzed together with MARIN’s partner ECN based on its extensive expertise in turbine design, mechanics and dynamics. Aart van der Pal, Manager Integral Wind Turbine Design of ECN, said, “Breaking wave loads can affect the extreme and fatigue loads on the foundation, tower, turbine blades, shaft, gearbox and generator, aspects that have not been studied in detail so far. This will need to be taken into account in the design process.”

Together with a number of other partners, MARIN and ECN are in the process of starting up a Joint Industry Project (JIP) with the acronym ‘WiFi’: Wave impacts on Fixed turbines. As independent institute in the Offshore and Shipping industry, MARIN has a lot of experience in leading JIPs. The objective of the WiFi JIP is to develop a design methodology for offshore wind turbines that includes the effect of steep and breaking waves.

 

Maritime Reporter June 2014 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

Maritime NZ Oil Spill Response Review: Submissions

Maritime New Zealand (MNZ) says it invites submissions on its draft updated New Zealand Marine Oil Spill Response Strategy 2014 (the draft Strategy). The draft Strategy, (available at http://bit.

SHIPPINGInsight 2014 Agenda Announced

Annual Conference, Exhibition and Networking Event Brings Together Shipowners and Technology Companies to Address Practical Solutions for Efficient Operations The

VIDEO: HMS Queen Elizabeth Floats Out

A timelapse video of HMS Queen Elizabeth floating out of her dock for the first time is now available at http://www.youtube.com/watch?v=P0ZjQz9vEKw. The float out of the 65,

Offshore

2545 Candidates Vie for 11 Positions in Maersk Drilling

2545, that is exactly how many applicants applied for the 11 MITAS engineer positions available in Maersk Drilling in 2014. The Maersk International Technology and Science Programme,

GDI Awards N-KOM US$110-M Contracts

Gulf Drilling International (GDI) Limited, a subsidiary of Gulf International Services (GIS), the largest oilfield service company in Qatar, has awarded two contracts

Statoil Awarded Licence Offshore Colombia

Statoil has been awarded interest in the COL4 licence offshore Colombia in the Caribbean Sea in the 2014 Colombia Licensing Round. Statoil will hold 33,33% in the licence.

Energy

Semco and PV Join Forces for Rig Upgrade

Semco Maritime and PetroVietnam Marine Shipyard join forces to establish high class rig upgrade player in South East Asia - Vung Tau Rig Services. The initiative

Statoil Awarded Licence Offshore Colombia

Statoil has been awarded interest in the COL4 licence offshore Colombia in the Caribbean Sea in the 2014 Colombia Licensing Round. Statoil will hold 33,33% in the licence.

Gazprom to Extend Gas Supplies from Kazakhstan

Astana hosted today a working meeting between Alexander Medvedev, Deputy Chairman of the Gazprom Management Committee and Uzakbai Karabalin, Minister of Oil and Gas of the Republic of Kazakhstan.

 
 
Maritime Careers / Shipboard Positions Maritime Security Naval Architecture Offshore Oil Pipelines Pod Propulsion Ship Repair Ship Simulators Shipbuilding / Vessel Construction Winch
rss | archive | history | articles | privacy | terms and conditions | 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: 0.1735 sec (6 req/sec)