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Welcome to Task 23 Subtask 2 Code Comparison Collaborative (OC3)

All of the presentations and reports are part of the of public record.

The following FTP information takes you to the research results of Subtask 2 Codes Comparison Collaborative (OC3)

Hostname: ftp.ieawind.org
Username: task23@ieawind.org
Password: OC3 (Case Sensitive)

Meeting 1 Washington D.C., USA
October 2004

Kick Off Meeting Coupled turbine/substructure dynamic modeling - A Kick-off meeting was held. Representatives from Denmark, Japan, Norway, the United Kingdom, and the United States attended. The October meeting attracted 32 participants from 8 countries. To maximize the benefit to the research community and to take advantage of experience with current turbine modeling effort in shallow water, it was decided to include both shallow and deep-water modeling.

No presentations available

Meeting 2 Roskilde, Denmark
January 2005

No agenda available

Floating Foundation Test
Adams (MP4)

Measurements and modelling wind speeds to future
turbine hub-heights
Barthelmie

Bergdahl
Ice loads on wind power plants
Wave modelling in deep and shallow water at Chalmers
Movies

Offshore modelling needs workshop
Camp

Turbu Offshore
Engelen

Offshore Modeling Needs Workshop
Frandsen

Design Forces
Gravesen

Ice Forces to Wind Turbine Foundations in Denmark
Gravesen

Accuracy in wave loads
Gravesen

Presentation of the Aeroelastic Code HAWC2
Hansen

Offshore Wind Energy Technology and Deployment
Hauge Madsen

Integrated Modelling Methods used by Vestas
Hogedahl

Ice Loading on Danish Wind Turbines Part 2
Ice Loading

Simple method of combining wind and wave load
Jørgensen

Sea Ice Loads on Offshore Structures
Karna

Reflections on the Role of the IEA in Facilitating R&D for Offshore Wind Systems
Manwell

Molle (MP4)

Turbine modelling and design initiatives at EE
Morch

Offshore Foundations for 23m-29m
Volund

Integrated Modelling of Offshore Wind Turbine Dynamics - Status and Future Needs
Passon

Dynamic Simulations of Deep Water Floating Offshore Wind Turbine Concepts
Sclavounos

Modelling of truss type structures for offshore wind turbine applications –
What is required?
Skiple

Choice of Safety Code Format for Offshore Turbines
Tarp-Johansen

Meeting 3 Trondheim, Norway
June 2005

Lessons learned from the EU-JOULE project VEWTDC
Schepers

Modelling of deep water support structures for offshore wind turbines
Camp

Critical issues in wind turbine design
Frandsen

Dynamic analysis of floating deep water windmills – Tower/substructure response
Hansen

Development of Fully Coupled Development Aeroelastic and Hydrodynamic Models for Floating Offshore Wind Turbinesfor Turbine
Jonkman

Considerations on the Verification Plan for Offshore Wind Turbine Design Codes
Passon

Minutes

Meeting 4 Roskilde, Denmark
October 2005

Wave kinematics data for OC3
Camp

Support structure matrix& soil conditions for OC3
Passon

Turbulence for the IEA OC3 project
Thomsen

Structural behaviour of NREL 5MW using FLEX5
Mørch

Control design for a pitch-regulated, variable speed wind turbine
Hansen

State-of-the-art and Development Needs of Simulation Codes
for Offshore Wind Turbines
Passon

Jonswap and Boussinesq Modelling
Gravesen

Comments on the support structure matrix

Minutes

Meeting 5 Pittsburgh, USA
June 2006

Aerodynamics Issues
Buhl

Phase VI Planning: Floating Platform Proposal
Jonkman

NREL 5MW Offshore Baseliine Turbine and Controller Specifiications
Jonkman

Phase I Simulations: Rev. 1
Jonkman

Considerations on simplified modelling approaches for braced support structures
Passon

Minutes

Meeting 6 Stuttgart, Germany
January 2007

IEA Offshore Code Comparison Collaborative (OC3) Phase II Comparison Meeting Agenda

Meeting 7 Hamburg, Germany
September 2007

Dynamics Modelling and Loads Analysis of an Offshore Floating Wind Turbine
Jason Jonkman

Tripod modelling in HAWC2
Torben J. Larsen

IEA Offshore Code Comparison Collaborative (OC3) Meeting notes
Jason Jonkman

OC3 - Benchmark Exercise of Aero-elastic Offshore Wind Turbine Codes
Patrik Passon

A method to avoid negative damped low frequent tower vibrations for a floating, pitch controlled wind turbine
Torben J. Larsen

Meeting 8 Berlin, Germany
December 2007

Offshore Code Comparison Collaboration within IEA Wind Annex XXIII: Phase II Results Regarding Monopile Foundation Modeling

NREL – Jonkman, Butterfifield
Risø – Larsen
SWE – Passon
GH – Camp, Nichols
CENER – Azcona, Martinez

Phase IV – Floating Platform Modeling
Jonkman

Linear Wave Theory
Moe

Minutes

Meeting 9 Esbjerg, Denmark
September 2008

Agenda/Minutes OC3 Phase IV – Floating
Jonkman

Review of OC3 Project
Jonkman

Offshore Code Comparison Collaborative (OC3) Phase III– Tripod Finite Element and Multibody Simulation of the Support Structure Dynamics of OWECs
Kohlmeier

Task 23 Review
Lemming

Offshore Floating Wind Turbine Status
Nygaard

Phase IV: Floating Wind Turbines Simulations
Vergara

Status quo in OC3 project at Fraunhofer CWMT
Vorpahl

Status quo in OC3 project at Fraunhofer CWMT Results
Vorpahl

Meeting 10 Risø-DTU, Denmark
February 25-26 2009

Development and calibration of an engineering model for computation
of wake velocity deficits
Madsen

CFD modelling of the interaction between the Surface Boundary
Cabezon

Offshore grids and wind power control
Carlson

Validation of power fluctuation
simulation model
Cutululis

Wake model evaluation in the UPwind
and POW'WOW projects
Barthelmie

Power Fluctuations
Brand

Wake modelling
Brand

Eastern Wind Integration and Transmission Study
Brower

High-resolution mesoscale modelling of wakes
Brower

Offshore WRF simulations: Geographical variation in wind power production
for the North Sea
Byrkjedal

Reduction of Wind Power Variability by Aggregation of wind farms to large interconnected offshore grids
Dobschinsk

New data assimulation techniques for short-term wind energy forecast model
with a rapid update cycle
Drax

Frendsen

Introduction – Wake Effects
Frendsen

TOPFARM - background and vision
Larsen

Workshop Introduction
Lemming

Wind Farm and Wake Modeling at NREL
Moriarty

Regime switching models for preduction of wind power fluctuations
Pinson

CFD model of wind turbine wake in atmospheric turbulence using body forces
Rethore

Plansideas for Wind farm CFD
Sanderse

Wake measurements in a research farm consisting of 5 turbines 4 years data
Schepers

Wind farm and wake modelling at DTU
Sørensen

The effect of geographical spreading on wind power fluctuations
Sørensen

Wind Power Time Series simulation model
Sørensen

Wake meandering modeling for wind turbine loading
Trujill

Comparison of power fluctuations from onshore and offshore
Vigueras

Favourable meteorological conditions for
severely variable wind speeds at Horns Rev
Vincent

Meeting 11 Stockholm, Sweden
June 2009

No Agenda Available

Selected Plots
Fylling

Nordic consortium: Wind turbine Wake Interaction
Henningson

OC3 –Future Planning
Jonkman

OC3 Phase IV –Updates Since Roskilde
Jonkman

Review of OC3 Project
Jonkman

Hywind Multibody Simulation of the Support Structure Dynamics of
Floating Wind Turbines
Kohlmeier

Apia Wind Presentation
Lasa

OC3 Continuation Proposal
Musial

IEA Phase IV of OC3 Offshore Floating Wind Turbine Status
Nygaard

Proposal: Follow-on project
Louis Quesnel

Minutes

flags

Task 23 Publications

Final Reports for Task 23

Subtask1 Final Report

Subtask2 Final Report

Task23 Final Management Report

Subtask 2 Past Meetings and Associated Documents and Research Results

The list on the center represent all the meetings of Task 23 Subtask 2.

Cost-effective offshore wind turbines make use of a variety of support structures including floating structures, fixed-bottom monopiles, gravity bases, and space-frames—such as tripods and lattice frames (“jackets”). In recent years, codes originally used for analysis of land-based wind turbine have been expanded to include additional dynamics pertinent to offshore installations, including the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structure. This OC3 work was begun to validate these sophisticated codes and to verify their accuracy and correctness for offshore wind systems.

To test the newly developed codes, the OC3 participants met frequently to discuss modeling strategies, develop a suite of benchmark models and simulations, run the simulations and process the simulation results, and compare and discuss the results. The OC3 project was performed through technical exchange among a group of international participants from universities, research institutions, and industry researchers in Denmark, Germany, the Republic of Korea, the Netherlands, Norway, Spain, Sweden, the United Kingdom, and the United States. Most of the aero-hydro-servo-elastic codes developed for modeling the dynamic response of offshore wind turbines and available in 2009 were tested within OC3.

Unlike previous code verification activities, this OC3 work was designed to verify the dynamics of offshore support structure as part of the dynamics of the complete system. To encompass the variety of support structures required for cost effectiveness at varying offshore sites, different support structures (for the same wind turbine) were investigated:

• In Phase I, the NREL-designed simulation of a 5-MW offshore wind turbine was installed on a monopile with a rigid foundation in 20 m of water.
• In Phase II, the foundation of the monopile from Phase I was made flexible by applying different models to represent the soil-pile interactions.
• In Phase III, the water depth was changed to 45 m and the monopile was replaced with a tripod substructure, which is one of the common space-frame concepts proposed for offshore installations in water of intermediate depth.
• In Phase IV, the wind turbine was installed on a floating spar-buoy in deep water (320 m).

The verification activities performed in OC3 were important because the advancement of the offshore wind industry is closely tied to the development and accuracy of dynamics models. Vital experiences and knowledge been exchanged among the project participants, and the lessons learned have helped identify deficiencies in existing codes and needed improvements.