oc5 project phase ib: validation of hydrodynamic loading ... · oc5 phase ib • objective:...

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

OC5 Project Phase Ib: Validation of Hydrodynamic Loading on

a Fixed, Flexible Cylinder for Offshore Wind Applications

DeepWind Conference – Trondheim, Norway

Amy Robertson January 21, 2016

2

Co-Authors • Fabian F. Wendt - National Renewable Energy Laboratory, Colorado, USA • Jason M. Jonkman - National Renewable Energy Laboratory, Colorado, USA • Wojciech Popko - Fraunhofer IWES, Germany • Henrik Bredmose – Technical University of Denmark, Denmark • Michael Borg - Technical University of Denmark, Denmark • Flemming Schlutter - Technical University of Denmark, Denmark • Jacob Qvist - 4Subsea, Norway • Roger Bergua - Alstom Wind, Spain • Rob Harries - DNV GL, England • Anders Yde - Technical University of Denmark, Denmark • Tor Anders Nygaard - Institute for Energy Technology, Norway • Luca Oggiano - Institute for Energy Technology, Norway • Pauline Bozonnet - IFP Energies nouvelles, France • Ludovic Bouy - PRINCIPIA, France • Carlos Barrera Sanchez - Universidad de Cantabria – IH Cantabria, Spain • Raul Guanche García - Universidad de Cantabria – IH Cantabria, Spain • Erin E. Bachynski - MARINTEK, Norway • Ying Tu - Norwegian University of Science and Technology, Norway • Ilmas Bayati - Politecnico di Milano, Italy • Friedemann Beyer - Stuttgart Wind Energy, University of Stuttgart, Germany • Hyunkyoung Shin - University of Ulsan, Korea • Matthieu Guerinel - WavEC Offshore Renewables, Portugal • Tjeerd van der Zee - Knowledge Centre WMC, the Netherlands

3

IEA Wind Tasks 23 and 30 (OC3/OC4/OC5)

• Verification and validation of offshore wind modeling tools are need to ensure their accuracy, and give confidence in their usefulness to users.

• Three research projects were initiated under IEA Wind to address this need:

OC3 = Offshore Code Comparison Collaboration (2005-2009) OC4 = Offshore Code Comparison Collaboration, Continuation (2010-2013) OC5 = Offshore Code Comparison Collaboration, Continuation, with

Correlation (2014-2017)

4

OC5 Project Phases

Phase I: Monopile - Tank Testing

Phase II: Semi - Tank Testing

Phase III: Jacket/Tripod – Open Ocean

• OC3 and OC4 focused on verifying tools (tool-to-tool comparisons) • OC5 focuses on validating tools (code-to-data comparisons)

5

OC5 Phase Ib

• Objective: validate hydrodynamic loads and acceleration response for a fixed, flexible cylinder

• Test Data from Wave Loads Project: o 3-year project with goal of improving

numerical models for wave loads on offshore wind turbines

o Carried out collaboratively by DTU Wind Energy, DTU Mechanical Engineering, and DHI

o Performed at shallow-water basin at DHI o Thank you to: Ole Petersen at DHI and

Henrik Bredmose and Michael Borg at DTU for graciously supplying the data and information needed for this phase of the OC5 project.

6

Test Set-Up

• 1:80 scale, flexible cylinder • On slope – to create steep waves • Tests done at two water depths:

0.51 m and 0.26 m (40 and 20 m full scale)

• Measurements used: o Wave elevation o Acceleration at top mass of cylinder o Total hydrodynamic force on cylinder

7

Tests Simulated

• 7 Datasets were examined: o 4 regular cases

– 2 water depths – 2 wave heights

o 3 irregular cases – 2 water depths – 2 wave heights

• First regular wave case used for calibration

Test # Wave Type Water Depth (m) H/Hs (m) T/Tp (s) Gamma CA CD

1 Regular 0.51 0.090 1.5655 1.22 1.0

2 Regular 0.51 0.118 1.5655 1.22 1.0

3 Irregular 0.51 0.104 1.40 3.3 1.0 1.0

4 Irregular 0.51 0.140 1.55 3.3 1.0 1.0

5 Regular 0.26 0.086 1.565 1.22 1.0

6 Regular 0.26 0.121 1.565 1.22 1.0

7 Irregular 0.26 0.133 1.560 3.3 1.0 1.0

8

Summary of Tools and Modeling Approach Participant Code Wave Model (Reg/Irr) Wave Elevation Hydro Model

Structural Model Number DOFs

4Subsea OrcaFlex FNPF kinematics FNPF kinematics ME FE, RDS 160 elements 960 DOFs GE SAMCEF Wind Turbines (S4WT) 5

th Order Stokes/ Linear Airy Stretching ME FE (TS), RD 13 elements 84 DOF DNV GL-ME Bladed 4.6 6

th and 8th Order SF/ Linear Airy Measured ME FE (TS), MD 8 (CB)

DNV GL-PF Bladed 4.6 Linear Airy Measured 1st Order PF Rigid N/A

DTU-HAWC2 HAWC2 6th and 8th Order SF/L. Airy & FNPF kinematics Stretching & FNPF kin. ME FE (TS), RDS

20 elements, 126 DOF

DTU-HAWC2-PF HAWC2 6th and 8th Order SF/L. Airy Stretching 1st Order PF FE (TS), RDS 31 elements, 192 DOF DTU-BEAM OceanWave3D FNPF kinematics FNPF kinematics ME+Rainey FE (EB), RD 160 DOFs

IFE 3Dfloat FNPF kinematics FNPF kinematics ME FE (EB), RDS 62 elements, 378 DOF IFE-CFD STAR CCM CFD CFD-derived CFD Rigid N/A

IFP-PRI DeeplinesWind 3rd Ord. SF/ Linear Airy Measured ME FE 200 elements

UC-IHC IH2VOF FNPF kinematics FNPF kinematics ME Rigid N/A

MARINTEK RIFLEX 2nd Order Stokes & FNPF

kinematics Measured & FNPF kin. ME

FE(E-B), RDS, FS

167 elements, 1002 DOF

NREL-ME FAST 2nd Order Stokes & FNPF

kinematics Measured & FNPF kin. ME FE (TS), MD 4 (CB)

NREL-PF FAST 2nd Order Stokes Measured 2nd Order PF Rigid N/A

NTNU-Lin FEDEM 7.1 Linear Airy None ME FE (EB), RD 13 elements, 84 DOF

NTNU-Stokes5 FEDEM 7.1 5th Order Stokes None ME FE (EB), RD 13 elements, 84 DOF

NTNU-Stream FEDEM 7.1 Stream Function None ME FE (EB), RD 13 elements, 84 DOF

PoliMi POLI-HydroWind 2nd Order Stokes None ME FE (EB), RD 23 elements, 69 DOF

SWE SIMPACK +HydroDyn 2nd Order Stokes None ME FE (TS), MD 50

UOU UOU + FAST 2nd Order Stokes None ME Rigid N/A

WavEC Wavec2Wire 2nd Order Stokes /Linear Airy Measured 2nd/1st Order PF Rigid N/A

WMC FOCUS6 (PHATAS) FNPF kinematics FNPF kinematics ME FE (TS), MD 12 (CB)

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Calibration

• Group calibrated CA and CD coefficients based on Test 1, to get appropriate levels of force o All participants used same values

to have consistency in model parameters – to better see differences in modeling approach

• A CA value of 1.22 was required, which is larger than expected o Suspect the higher measured loads

might be due to reflected waves that were not modeled in the simulation

212 4D M

DF C Du u C uπρ ρ= +

Morison’s Equation

10

Test 1 – Regular Wave – Deeper Water - Force Results

Time (s)

70 70.5 71 71.5 72 72.5 73 73.5 74 74.5 75

Tota

l for

ce (N

)

-4

-2

0

2

4

6Test 1, 0.51 m water depth, H = 0.09 m, T = 1.5655 s

DNV-GL-ME-elvDNV-GL-PF-elvDTU-BEAM-kinDTU-HAWC2DTU-HAWC2-PFDTU-HAWC2-kinEXPERIMENTIFE-CFDIFE-kinIFP-PRI-elvMARINTEK-elvMARINTEK-kinNREL-MENREL-ME-elv1NREL-ME-elv2NREL-ME-kinNREL-PFNREL-PF-elv1NREL-PF-elv2NTNU-LinNTNU-Stokes5NTNU-StreamPOLIMISWEUOUWMC-kin4Subsea-kinGEUC-IHC-kinWavEC

Frequency (Hz)

0 0.5 1 1.5 2 2.5 3

Tota

l for

ce (N

)2

/Hz

100

200

300

400

500

600

700

800

11

Test 6 – Regular Wave – Shallower Water - Force Results

Time (s)

70 70.5 71 71.5 72 72.5 73 73.5 74 74.5 75

Tota

l for

ce (N

)

-10

-5

0

5

10Test 6, 0.26 m water depth, H = 0.086 m. T = 1.565 s

DNV-GL-ME-elvDNV-GL-PF-elvDTU-BEAM-kinDTU-HAWC2DTU-HAWC2-kinEXPERIMENTIFE-kinMARINTEK-elvNREL-MENREL-ME-elv1NREL-ME-elv2NREL-ME-kinNREL-PFNREL-PF-elv1NREL-PF-elv2NTNU-LinNTNU-Stokes5NTNU-StreamPOLIMISWE4Subsea-kinGEUC-IHC-kinWavEC

Frequency (Hz)

0 0.5 1 1.5 2 2.5 3

Tota

l for

ce (N

)2

/Hz

100

200

300

400

12

1st Peak Force Component

Deeper Water Depth

Shallower Water Depth

Peak Force1 (N)0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

DNV-GL-ME-elvDNV-GL-PF-elvDTU-BEAM-kin

DTU-HAWC2DTU-HAWC2-PFDTU-HAWC2-kin

EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv

MARINTEK-elvMARINTEK-kin

NREL-MENREL-ME-elv1NREL-ME-elv2

NREL-ME-kinNREL-PF

NREL-PF-elv1NREL-PF-elv2

NTNU-LinNTNU-Stokes5NTNU-Stream

POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC

Test 1, 0.51 m water depth, H = 0.09 m, T = 1.5655 s

Peak Force1 (N)0 0.5 1 1.5 2 2.5 3 3.5 4 4.5



EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv



NREL-ME-kinNREL-PF



POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC


Peak Force1 (N)0 0.5 1 1.5 2 2.5 3 3.5 4 4.5


DTU-HAWC2DTU-HAWC2-kin

EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME

NREL-ME-elv1NREL-ME-elv2

NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


Peak Force1 (N)0 0.5 1 1.5 2 2.5 3 3.5 4 4.5



EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME


NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


13

2nd Peak Force Component

Deeper Water Depth


Peak Force2 (N)0 0.5 1 1.5 2 2.5 3 3.5



EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv



NREL-ME-kinNREL-PF



POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC


Peak Force2 (N)0 0.5 1 1.5 2 2.5 3 3.5



EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv



NREL-ME-kinNREL-PF



POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC


Peak Force2 (N)0 0.5 1 1.5 2 2.5 3 3.5



EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME


NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


Peak Force2 (N)0 0.5 1 1.5 2 2.5 3 3.5



EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME


NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


14

3rd Peak Force Component

Deeper Water Depth


Peak Force3 (N)0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6



EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv



NREL-ME-kinNREL-PF



POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC


Peak Force3 (N)0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6



EXPERIMENTIFE-CFD

IFE-kinIFP-PRI-elv



NREL-ME-kinNREL-PF



POLIMISWEUOU

WMC-kin4Subsea-kin

GEUC-IHC-kin

WavEC


Peak Force3 (N)0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6



EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME


NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


Peak Force3 (N)0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6



EXPERIMENTIFE-kin

MARINTEK-elvNREL-ME


NREL-ME-kinNREL-PF



POLIMISWE

4Subsea-kinGE

UC-IHC-kinWavEC


15

700 705 710 715 720 725 730

Wav

e E

lev.

(m)

-0.2

-0.1

0

0.1

0.2

EXPERIMENT

4Subsea-kin

DNV-GL-ME-elv

DNV-GL-PF-elv

DTU-BEAM-kin

DTU-HAWC2-kin

IFE-kin

MARINTEK-elv

NREL-ME-elv1

NREL-ME-elv2

NREL-PF-elv1

NREL-PF-elv2

WavEC

700 705 710 715 720 725 730

Tota

l for

ce (N

)

-20

-10

0

10

20

30

Time (s)

700 705 710 715 720 725 730X-a

ccel

at 1

65 c

m (m

/s2

)

-1

-0.5

0

0.5

Test 7 – Irregular Wave – Shallower Water

16

Irregular Waves – Exceedance Probability Plots

Force (N)0 1 2 3 4 5 6 7 8 9 10

Pex

ceed

ance

10 -4

10 -3

10 -2

10 -1

10 0Test 3

Acceleration (m/s 2 )

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Pex

ceed

ance

10 -4

10 -3

10 -2

10 -1

10 0

Force (N)0 5 10 15 20 25 30

Pex

ceed

ance

10 -4

10 -3

10 -2

10 -1

10 0Test 7

Acceleration (m/s 2 )

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Pex

ceed

ance

10 -4

10 -3

10 -2

10 -1

10 0

DNV-GL-ME-elvDNV-GL-PF-elvDTU-BEAM-kinDTU-HAWC2DTU-HAWC2-PFDTU-HAWC2-kinEXPERIMENTIFE-kinIFP-PRI-elvMARINTEK-elvNREL-ME-elv1NREL-ME-elv2NREL-PF-elv1NTNU-LinPOLIMISWEUOUWMC-kin4Subsea-kinGEUC-IHC-kinWavEC

17

Conclusions • Higher-order wave theory important in capturing higher-order

components of hydrodynamic force o Extreme loads o Excitation of structural frequencies o Most important in shallow water

• Sloped seabed creates complex wave kinematics o Standard wave theories cannot account for slope o CFD-type analysis might be needed to create wave kinematics for non-

flat seabed conditions

• Majority of offshore wind modeling tools do not presently address breaking waves o Complex wave theories and CFD can accurately model steep waves

that will break o Need to model the impulsive load that a breaking wave will impart on

the structure o Some codes are seeking to include this

Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute • Battelle

Thank You!

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Amy Robertson +1 (303) 384 – 7157 [email protected]

Slide Number 1Co-Authors IEA Wind Tasks 23 and 30 (OC3/OC4/OC5)OC5 Project PhasesOC5 Phase IbTest Set-UpTests SimulatedSummary of Tools and Modeling ApproachCalibrationTest 1 – Regular Wave – Deeper Water - Force ResultsTest 6 – Regular Wave – Shallower Water - Force Results1st Peak Force Component2nd Peak Force Component3rd Peak Force Component Test 7 – Irregular Wave – Shallower WaterIrregular Waves – Exceedance Probability PlotsConclusionsThank You!

oc5 project phase ib: validation of hydrodynamic loading ... · oc5 phase ib • objective:...

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