Print Email Facebook Twitter Operability Analysis of Wind Farm Maintenance with the Damen FCS2610 Title Operability Analysis of Wind Farm Maintenance with the Damen FCS2610 Author Sneep, T.P. Contributor Van Oosten, C.A. (mentor) Faculty Mechanical, Maritime and Materials Engineering Department Offshore and Dredging Engineering Date 2016-04-11 Abstract The Damen Twin Axe Fast Crew Supplier (FCS)2610 is an offshore wind farm maintenance vessel that can safely and efficiently transfer mechanics between land and a wind farm. The thesis objective is to research the operational capability of the FCS by gaining insight into the push docking procedure of the transfer process. To keep the vessels bow steady and in position against the wind turbine tower during push docking, a fender is placed on the bow. Currently, it is not clear which phenomena play a role in making the fender stick or slip. This makes the fender a bottleneck in the relatively low operation profile, leaving room for improvement. In the push docking procedure condition, the FCS is pushed against the turbine tower using thrust generated by the drive train. The fender provides friction between the vessel and the tower. Disturbances by the environment, like waves, cause the bow to either slip or stick along the tower. An unexpected or long distance slip makes it unable for the mechanics to transfer from the FCS to the turbine tower. The objective of this research firstly is to gain insight in the interaction between the fender and FCS’s motion behaviour and its influences on the friction performance – the obstruction of the sliding motions between the fender and wind turbine. A second objective is to develop a prediction method to define safe transfer operations based on the fender-vessel friction performance in a yearly described sea – the operability. By use of calculations and simulations – in which boat, fender and environment are represented as real life components – two models are built that provides a description of the sea behaviour of the FCS and simulates the slick/slipping process of the fender against the wind turbine. In both models irregular head waves are described by a Jonswap spectrum. Model 1 merely represents the stick condition by using a frequency domain approach, in which the FCSs bow is ‘hinged’ against the turbine tower by springs in horizontal, (transversal) and vertical direction. Model 2 describes both stick and slip condition, describing the vessel motion interaction in the time domain. The fender is described by separate components, combining a ‘negative deflection’ based reaction force, a linear spring system and a (modified) coulomb friction block simulating the stick/slip phenomenon. Both models were validated in stick condition with results from towing tank tests. To define safe transfer possibilities, a condition check method judges the simulation conditions to be either safe or to be unsafe for transfers. With this the yearly ability to perform maintenance – operability – is determined. Based on the results of the sensitivity study, several influential design parameters can be identified. During stick conditions, in vertical direction a less stiff fender, higher static friction coefficient and increased thrust results in an increased operability. During stick and slip conditions, the thrust force has a major influence, higher thrust means an increasing operability. The dynamic friction coefficient is concluded to have less influence. The non-linear model causes the operability to be non-linear. In addition the operability is highly influenced by the simulation parameters (most important the friction slope) and the safety restrictions of the condition checker. These are both unknown but arbitrary chosen for this thesis. Therefore further investigation into these parameters is required to provide an accurate description of the yearly operability. Subject slipoperational capabilityoperabilityhydrodynamicsfrequency domaintime domaincatamaranfenderfrictionstick To reference this document use: http://resolver.tudelft.nl/uuid:0f87562b-6725-415e-bfb9-f311ff973ad5 Part of collection Student theses Document type master thesis Rights (c) 2016 T.P. Sneep Files PDF THESIS_TPSneep_final_SMALL.pdf 4.5 MB Close viewer /islandora/object/uuid:0f87562b-6725-415e-bfb9-f311ff973ad5/datastream/OBJ/view