IEA Wind Task 30 OC4 Project Offshore Code Comparison Collaboration Continuation Brian Smith National Renewable Energy Laboratory IEA ExCo Meeting 68 Dublin, Ireland October, 2011
OC4 Motivation Offshore Wind Turbines (OWTs) are designed using aerohydro-servo-elastic codes The codes must be verified to assess their accuracy
OC4 Activities and Objectives The IEA Offshore Code Comparison Collaboration Continuation (OC4) is an international forum for OWT dynamics code verification Activities Discuss modeling strategies Develop suite of benchmark models & simulations Run simulations & process results Compare & discuss results Objectives 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
OC4 Project Organizational Structure Wojchiech Popko Amy Robertson
OC4 Participation 78 participants from 32 organizations in 14 countries have participated in the task. Country Commitments 10 Participating Codes 22+ Country Australia Austria Canada Chinese Wind Energy Association Denmark European Commission European Wind Energy Association Finland Germany Greece Ireland Italy Japan Korea Mexico The Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom United States Response No Response No Response Considering Declined Declined Considering No Response Considering No Response No Response Considering Declined Declined 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
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 Approach 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 Phase I: UpWind Jacket Phases 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 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 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 o Turbulent winds with irregular waves 3.X Onshore Wind Turbine Flexible tower, drivetrain, & rotor Rigid substructure Aero-servo-elastics without hydro: o Steady & turbulent winds
The Reference Jacket Structure
Output Locations on Jacket for Response Comparison Transition piece and grout connection to tower
E-mail coordination OC4 Coordination & Meetings Meetings o Net-meetings held every 1-2 months o Physical meetings held 1-2 times per year o 3 rd 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 to IEA Wind Task 30 members
Budget Status 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 Planned Annual Budget and Revenues COSTS ( ) Budget Yearly Labor 36,333 Travel 7,000 Other costs 1,667 TOTAL 45,000 REVENUES ( ) 0 Expected 50,000 Revenues ( )
Schedule ID Task Name 1 ExCo Approval of Annex 30 2 Receive Commitment Letters 3 Receive Funds 4 Jacket Code Comparison - Work Package 1 5 Publish Paper or Report on Jacket 6 Establish Floating Design Concept 7 Floating Platform - Work Pakage 2 8 Report on Floating Structure 9 Code Validation Data Comparison Workshop 10 Report on Workshop 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 2010 2011 2012 2013 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 11/9 2/1 3/31 4/30 11/1 5/2 6/1 9/22 10/31 12/1 12/18 1/29 4/30 5/20 9/30 10/31 4/28 4/30 4/30 = 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 Semisubmersible Concept 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
IEA Wind Annex 30 OC4 Project The Offshore Code Comparison Collaboration Continuation Thank You! Presented by Brian Smith (brian.smith@nrel.gov) National Wind Technology Center