IEA Wind Task 30 – OC4 Project
O
ffshore
C
ode
C
omparison
C
ollaboration
C
ontinuation
Brian Smith
National Renewable Energy Laboratory
IEA ExCo Meeting 68 Dublin, Ireland
OC4 Motivation
• Offshore Wind Turbines (OWTs) are designed using
aero-hydro-servo-elastic codes
OC4 Activities and Objectives
• Discuss modeling strategies
• Develop suite of benchmark models & simulations
• Run simulations & process results
• Compare & discuss results
• Assess simulation accuracy & reliability
• Train new analysts how to run codes correctly
• Investigate capabilities of implemented theories
• Refine applied analysis methods
• Identify further R&D needs
Activities
Objectives
The IEA Offshore Code Comparison Collaboration Continuation (OC4) is an international forum for OWT dynamics code verification
OC4 Project Organizational Structure
Amy Robertson Wojchiech Popko
OC4 Participation
Country Response
Australia No Response Austria No Response
Canada Considering
Chinese Wind Energy Association Committed
Denmark Committed
European Commission Declined European Wind Energy Association Declined
Finland Committed Germany Committed Greece Committed Ireland Considering Italy No Response Japan Committed Korea Considering Mexico No Response
The Netherlands Committed
Norway Committed
Portugal No Response
Spain Committed
Sweden Considering
Switzerland Declined United Kingdom Declined United States Committed
78 participants from 32 organizations in 14 countries have participated in the task.
Country Commitments – 10 • 3Dfloat • ADAMS-AeroDyn-HydroDyn • ADAMS-AeroDyn-WaveLoads • ADCoS-Offshore • ADCoS-Offshore-ASAS • ANSYS • Bladed • Bladed Multibody • FAST-AeroDyn-HydroDyn • FAST-AeroDyn-TimeFloat • FAST-CHARM3D • FEDEM-AeroDyn • FLEX5 • FLEX5-Poseidon • HAWC2 • Modelica • PHATAS • SESAM • Simo-Riflex • SIMPACK-AeroDyn-HydroDyn • USFOS-VpOne • VIDYN Participating Codes – 22+
OC4 Background and Overview: From OC3 to OC4
• IEA Task Wind 30 (OC4) is a follow-on task to IEA Wind Task 23 (OC3) • OC3 ran from 2005 to 2009 and also sought to verify OWT modeling codes • OC4 will continue the examination of more OWT configurations
Monopile Tripod Floating Spar Buoy
OC4 Approach & Phases
• All inputs are predefined:
o NREL 5-MW wind turbine, including control system
o Variety of support structures
o Wind & wave datasets
• A stepwise procedure is applied:
o Load cases selected to test different model features
• OC4 will run from 2010-2013
o Phase I: Jacket (nearing its end) o Phase II: Floating semisubmersible
(just starting)
o Validation Workshop in 2012
Approach
Phases
Phase II: DeepCwind Semisubmersible
Status of OC4 Phases
Phase I: Jacket
• Nearing completion of analysis
• Technical paper to be presented at International Offshore and Polar Engineering Conference (ISOPE) in Rhodes, Greece, June17- 23, 2012
Phase II: Semisubmersible
• DeepCwind semi design will be used • Design specification document will
be presented at next face-to-face meeting in November 2011
Load Cases to be modeled
1.X – Full-System Eigenanalysis• Full-system flexibility
• Elastic response only
• Compared natural frequencies &
damping ratios
2.X – Rigid
• Rigid turbine
• Aerodynamics without hydro:
o Steady & turbulent winds
• Hydrodynamics without aero:
o Regular & irregular waves
3.X – Onshore Wind Turbine
• Flexible tower, drivetrain, & rotor
• Rigid substructure
• Aero-servo-elastics without hydro:
o Steady & turbulent winds
4.X – Flexible Offshore Wind Turbine
• Flexible support structure
• Rigid tower-top
• Hydro-elastics without aero:
o Regular & irregular waves
5.X – Fully-Flexible Offshore WT
• Full-system flexibility
• Full aero-hydro-servo-elastics:
o Steady winds with regular waves
Output Locations on Jacket
for Response Comparison
Transition piece and grout connection to tower
OC4 Coordination & Meetings
• E-mail coordination • Meetings
o Net-meetings held every 1-2 months
o Physical meetings held 1-2 times per year
o 3rd physical meeting held at ISOPE
Conference in Hawaii, USA, June 2011
o Next meeting at EWEA Offshore 2011 in Amsterdam, Netherlands, November
• IEA Wind Task 23 and 30 SharePoint website:
o http://oc4.collaborationhost.net
o Hosted by NREL
o Includes meeting presentations, minutes, model and load case
descriptions, and simulation results
o Password required to access site, and certain directories open only
Budget Status
COSTS (€) Budget Yearly
Labor € 36,333 Travel € 7,000 Other costs € 1,667 TOTAL € 45,000 REVENUES (€) €0 Expected Revenues (€) € 50,000 Planned Annual Budget and Revenues • Annual fee = €5000 (~$7,205) per country to
support the Operating Agents • Over 3 years, OAs will receive:
o Total = € 150,000 (10 countries x €5000 x 3 years)
o NREL = €105,000
o Fraunhofer = € 45,000
• Invoices have been sent to 10 countries, but no funds have yet been received
• To date, OAs have been using task sharing to perform duties and will revert to cost sharing schedule once fees are received.
• Actual OA costs and participant man-month efforts (both for national projects and related
projects) will be collected at next physical meeting and reported at ExCo 69
Schedule
ID Task Name1 ExCo Approval of Annex 30 2
Receive Commitment Letters
3 Receive Funds
4 Jacket Code Comparison - W ork Package 1 5 Publish Paper or Report on Jacket
6
Establish Floating Design Concept
7 Floating Platf orm - Work Pakage 2 8 Report on Floating Structure 9
Code Validation Data Comparison Workshop
10 Report on W orkshop 11 Final Report 12 Kickoff Meeting #1 13 Meeting #2 14 Meeting #3 15 Meeting #4 16 Meeting #5 17 Meeting #6 18 Meeting #7 11/9 2/1 3/31 1/29 4/28 9/22 12/18 4/30 4/30 11/1 5/2 10/31 4/30 10/31 4/30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O 2010 2011 2012 2013 6/1 12/1 5/20 9/30 = Modified date
Summary
• OC4 aims to verify OWT dynamics tools
• Two different offshore wind turbine configurations are being tested: offshore jacket & semisubmersible • Code-to-code comparisons have agreed well
• Differences caused by variations in:
o Model fidelity
o Aero- & hydrodynamic theory
o Model discretization
o Numerical problems
o User error
• Verification is critical to advance offshore wind • OC4 will also hold an expert’s workshop on code
validation in late 2012 and will discuss the need for a follow-on task devoted to this topic
Semisubmersible Concept
IEA Wind Annex 30 – OC4 Project
The Offshore Code Comparison Collaboration Continuation
Thank You!
Presented by
Brian Smith ([email protected]) National Wind Technology Center
