CFD investigation of a complete floating offshore wind turbine

This chapter presents numerical computations for floating offshore wind turbines for a machine of 10-MW rated power. The rotors were computed using the Helicopter Multi-Block flow solver of the University of Glasgow that solves the Navier-Stokes equations in integral form using the arbitrary Lagrangian-Eulerian formulation for time-dependent domains with moving boundaries. Hydrodynamic loads on the support platform were computed using the Smoothed Particle Hydrodynamics method. This method is mesh-free, and represents the fluid by a set of discrete particles. The motion of the floating offshore wind turbine is computed using a Multi-Body Dynamic Model of rigid bodies and frictionless joints. Mooring cables are modelled as a set of springs and dampers. All solvers were validated separately before coupling, and the loosely coupled algorithm used is described in detail alongside the obtained results

Applicability of offshore mooring and foundation technologies for marine renewable energy (MRE) device arrays

Published onlineThe marine renewable energy (MRE) sector is progressing from single device units to device arrays. Currently, the mooring/foundation technologies used in MRE are based on offshore oil/gas industry practices. For MRE arrays to reach commercialization, several issues need to be addressed including the hy-drodynamic array layout, electrical infrastructure, operations, maintenance, control, moorings, foundations, installation and logistics. The DTOcean (The Optimal Design Tools for Ocean Energy Arrays) project is aimed at accelerating the industrial development of ocean energy power generation knowledge, and providing design tools for deploying the first generation of wave and tidal energy converter arrays. In this paper, the ap-plicability of offshore mooring/foundation technologies for marine renewable energy (MRE) device arrays are assessed. The paper introduces the criteria which can be used to appraise technologies and approaches rele-vant to MRE devices. Existing mooring/foundation technologies used in the offshore industry are summarized with examples given of MRE device deployments. The guidance from certification agencies which is used for the design and analysis of mooring/foundation systems is summarized. If not addressed, the failure to opti-mize the design of ocean energy arrays and failure to properly understand economic, environmental, or relia-bility impacts of individual components could have significant consequences for the overall project and sec-tor. The function and type of mooring and/or foundation system are determined by a number of factors including the cost, site characteristics, expected environmental loading and environmental or legislative con-straints and these factors are discussed

Mooring and Foundation Module Framework for DTOcean Tool

PublishedThe Optimal Design Tools for Ocean Energy Arrays project (DTOcean) is developing a system-level tool to assess cost, reliability, and environmental impact for marine renewable energy (MRE) systems. The DTOcean Tool will integrate several modules covering key aspects of MRE systems (i.e., array layout, moorings and foundations, electrical infrastructure, logistics, in addition to operations and maintenance). This report outlines the proposed architecture and main functions of the DTOcean mooring and foundation design module (the Work Package 4 or WP4 module) and its interaction with other elements and modules of the Tool. This document therefore presents the WP4 module framework which will be populated with algorithms and functions as the Tool is further developed. The module will comprise five sub-modules, in which calculations will be performed to determine and/or design the system and environmental loads, the electrical umbilical, mooring, and foundation systems as well as the foundation required for the electrical substation. Calculations performed in the sub-modules will be based on inputs provided by the user, other Tool modules, and data stored within the global Tool database. Criteria for determining design suitability will not be based solely on whether the specified components are suitable for keeping the device in position. The capital cost of each configuration will be estimated within the WP4 module, with reliability and environmental impact assessments also performed within the Tool. The framework of the WP4 module draws upon findings of previous WP4 deliverables, in which applicable mooring and foundation technologies and methods for their analysis have been reported.European Commission’s 7th Framework; Grant agreement number: 60859

A comprehensive assessment of the applicability of available and proposed offshore mooring and foundation technologies and design tools for array applications

PublishedThe function and type of mooring and/or foundation system are determined by a number of factors including: cost, site characteristics, expected environmental loading and environmental or legislative constraints. The design of the device and its mode of operation will also influence the decision making process. It is the role of DTOcean Work Package 4 to produce a decision making tool which has the capability to assess a range of technologies for the design and selection of mooring and foundation systems for marine renewable energy (MRE) device arrays. In this first deliverable report, criteria are introduced which can be used to appraise technologies and approaches relevant to MRE devices. Existing mooring and foundation technologies used in the offshore industry are summarised with examples given of MRE device deployments. A general overview of the design tools which are currently used for mooring and foundation design in the offshore and MRE industries is provided, along with a list of the capabilities of several commercially available software packages.European Commission’s 7th Framework; Grant agreement number: 60859

Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling

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