Wave impact on fixed offshore wind turbine, simulated with ComFLOW


BreaKin BreaKin is a new joint research initiative addressing the occurrence of wave breaking with a focus on deep-water condi- tions. The objective of the BreaKin JIP is to determine the occurrence of breaking waves, to model the associated water particle kine- matics and to describe the different types of wave loading that results. The overall purpose is to provide improved predictions of the breaking wave loads acting on offshore structures, including scale effects and to define the probability of occurrence. Contact: Janou Hennig, j.hennig@marin.nl


study of the new functionality will be performed. ComFLOW will be made available to all participants of ComMotion, including developments that were made in previous JIPs. Contact: Joop Helder, j.helder@marin.nl


ComMotion The new ComMotion JIP aims to further increase computational accuracy and efficiency of the ComFLOW Code when it comes to wave impact loading. The effects of structural response on impact loading will be addressed by including hydro-elastic models, and simulations with interactive moving bodies will be possible. Additionally, because any reliable wave impact simulation starts with a realistic modelling of the in- coming wave, algorithms for accurate, steep, irregular wave generation will be further developed. As part of the project deliverables, an extensive validation and benchmarking


ComFLOW-3 To numerically predict extreme wave loads on offshore structures, MARIN has been working together with the universities of Groningen and Delft in the development of the CFD method ComFLOW. Over the last few years many aspects have been addressed such as sloshing, air entrapment (“cushioning”), wave run up and deck impacts. In the most recent Joint Industry Project ComFLOW-3, MARIN’s dynamic mooring line modules were incor- porated, making it possible to realistically simulate the response of a complete floating structure during wave impact or mooring line failure. Contact: Tim Bunnik, t.bunnik@marin.nl


article on page 20). The objective of this JIP is to improve the way effects of steep and breaking waves are taken into account in the design methodology of fixed offshore wind turbines. For most offshore wind loca- tions, the water depth is such that breaking or near-breaking waves can occur, causing impulsive excitation of the foundation and considerable stresses and displacements in the tower and turbine. In the WiFi JIP a methodology will be devised to take extreme waves into account during the design process based on extensive model testing, numerical simulation and full-scale measure- ments. Contact: Erik-Jan de Ridder, e.d.ridder@marin.nl.


WiFi Another running JIP that deals with wave impacts is the WiFi JIP (see separate


ShorTCresT Recently, the ShorTCresT JIP was concluded, answering questions on extreme wave statistics, directional waves and the related wave impacts on offshore structures. The project included wave crest distributions beyond second order due to short-crestedness and wave steepness of the underlying wave spectrum, maximum crest heights under a deck area, the related global and local loading and typical loading levels on a platform deck in short-crested waves, as well as recommendations for analysis procedures involving short-crest- edness in platform design. Contact: Janou Hennig, j.hennig@marin.nl


report 15


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24