Abstract

Motivated by the increased interest in renewable energy and the need for validated hydrodynamic load models, a rigid monopile and a fully flexible large monopile wind turbine have been tested experimentally at a 1:50 model scale in irregular waves. Furthermore, a new engineering load model combining the conventional Morison equation for slender bodies with a frequency-dependent mass coefficient based on the first-order MacCamy and Fuchs solution has been developed and compared to Rainey’s load model and the model test results. Nonlinear wave kinematics based on the results of the nonlinear potential code REEF3D::FNPF have been applied as input to the numerical models. The new model better estimates the response of the monopile in the frequency range relevant for ringing events. The experimentally obtained 90th percentile bending moment response near the first natural frequency of the monopile is estimated within 2% by the new model with frequency-dependent mass coefficient, while a traditional Morison approach or the Rainey model overestimate the response by 47% and 74%, respectively.

References

1.
Kallehave
,
D.
,
Byrne
,
B. W.
,
LeBlanc Thilsted
,
C.
, and
Mikkelsen
,
K. K.
,
2015
, “
Optimization of Monopiles for Offshore Wind Turbines
,”
Philos. Trans. R. Soc. A: Math. Phys. Eng. Sc.
,
373
(
2035
), p.
20140100
.
2.
Suja-Thauvin
,
L.
,
2019
, “
Response of Monopile Wind Turbines to Higher Order Wave Loads
,” Ph.D. thesis, NTNU, Trondheim, Norway.
3.
Kristiansen
,
T.
, and
Faltinsen
,
O. M.
,
2017
, “
Higher Harmonic Wave Loads on a Vertical Cylinder in Finite Water Depth
,”
J. Fluid Mech.
,
833
, pp.
773
805
.
4.
Bachynski
,
E. E.
,
Kristiansen
,
T.
, and
Thys
,
M.
,
2017
, “
Experimental and Numerical Investigations of Monopile Ringing in Irregular Finite-Depth Water Waves
,”
Appl. Ocean Res.
,
68
, pp.
154
170
.
5.
Dadmarzi
,
F.
,
Thys
,
M.
, and
Bachynski
,
E. E.
,
2019
, “
Validation of Hydrodynamic Loads on a Large-Diameter Monopile in Regular Waves
,”
2019 38th International Conference on Ocean, Offshore and Arctic Engineering. Volume 7A: Ocean Engineering
,
Glasgow, Scotland, UK
,
June 9–14
,
American Society of Mechanical Engineers Digital Collection
, p. V07AT06A060.
6.
Bachynski
,
E. E.
,
Thys
,
M.
, and
Dadmarzi
,
F. H.
,
2020
, “
Observations From Hydrodynamic Testing of a Flexible, Large-Diameter Monopile in Irregular Waves
,”
J. Phys.: Conf. Ser.
,
1669
, p.
012028
.
7.
Suja-Thauvin
,
L.
,
Krokstad
,
J. R.
,
Bachynski
,
E. E.
, and
de Ridder
,
E.-J.
,
2017
, “
Experimental Results of a Multimode Monopile Offshore Wind Turbine Support Structure Subjected to Steep and Breaking Irregular Waves
,”
Ocean Eng.
,
146
, pp.
339
351
.
8.
de Ridder
,
E. J.
,
Aalberts
,
P.
,
Buchner
,
B.
, and
Peeringa
,
J.
,
2011
, “
The Dynamic Response of an Offshore Wind Turbine With Realistic Flexibility to Breaking Wave Impact
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
Rotterdam, The Netherlands
,
June 19–24
,
American Society of Mechanical Engineers Digital Collection
, pp.
543
552
.
9.
de Ridder
,
E. J.
,
Bunnik
,
T.
,
Peeringa
,
J. M.
,
Paulsen
,
B. T.
,
Wehmeyer
,
C.
,
Gujer
,
P.
, and
Asp
,
E.
,
2017
, “
Summary of the Joint Industry Project Wave Impact on Fixed Foundations (WiFi JIP)
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
Trondheim, Norway
,
June 25–30
,
American Society of Mechanical Engineers Digital Collection
, p. V010T09A081.
10.
Nielsen
,
A. W.
,
Schlütter
,
F.
,
Sørensen
,
J. V. T.
, and
Bredmose
,
H.
,
2012
, “
Wave Loads on a Monopile in 3D Waves
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
Rio de Janeiro, Brazil
,
July 1–6
,
American Society of Mechanical Engineers Digital Collection
, pp.
403
411
.
11.
Bredmose
,
H.
,
Slabiak
,
P.
,
Sahlberg-Nielsen
,
L.
, and
Schlütter
,
F.
,
2013
, “
Dynamic Excitation of Monopiles by Steep and Breaking Waves: Experimental and Numerical Study
,”
Volume 8: Ocean Renewable Energy
,
Nantes, France
,
June 9–14
,
ASME
, p.
V008T09A062
.
12.
Damgaard
,
M.
,
Ibsen
,
L. B.
,
Andersen
,
L. V.
, and
Andersen
,
J. K. F.
,
2013
, “
Cross-Wind Modal Properties of Offshore Wind Turbines Identified by Full Scale Testing
,”
J. Wind Eng. Ind. Aerodyn.
,
116
, pp.
94
108
.
13.
Shirzadeh
,
R.
,
Weijtjens
,
W.
,
Guillaume
,
P.
, and
Devriendt
,
C.
,
2015
, “
The Dynamics of an Offshore Wind Turbine in Parked Conditions: A Comparison Between Simulations and Measurements
,”
Wind Energy
,
18
(
10
), pp.
1685
1702
.
14.
Faltinsen
,
O. M.
,
Newman
,
J. N.
, and
Vinje
,
T.
,
1995
, “
Nonlinear Wave Loads on a Slender Vertical Cylinder
,”
J. Fluid Mech.
,
289
, pp.
179
198
.
15.
DNV
.
2010
. “
DNV-OS-j101: Design of Offshore Wind Turbine Structures
,” p.
142
.
16.
DNV
.
2014
. “DNV-RP-c205 Environmental Conditions and Environmental Loads.”
17.
DNV-OS-j101 design of offshore wind turbine structures
,” p.
238
.
18.
Wang
,
S.
,
Larsen
,
T. J.
, and
Bredmose
,
H.
,
2021
, “
Ultimate Load Analysis of a 10 MW Offshore Monopile Wind Turbine Incorporating Fully Nonlinear Irregular Wave Kinematics
,”
Marine Struct.
,
76
, p.
102922
.
19.
Keulegan
,
G.
, and
Carpenter
,
L.
,
1958
, “
Forces on Cylinders and Plates in an Oscillating Fluid
,”
J. Res. Nat. Bur. Stand.
,
60
(
5
), pp.
423
440
.
20.
Bearman
,
P. W.
,
Downie
,
M. J.
,
Graham
,
J. M. R.
, and
Obasaju
,
E. D.
,
1985
, “
Forces on Cylinders in Viscous Oscillatory Flow at Low Keulegan-Carpenter Numbers
,”
J. Fluid Mech.
,
154
, pp.
337
356
.
21.
MacCamy
,
R.
, and
Fuchs
,
R.
,
1954
,
Wave Forces on Piles: A Diffraction Theory
,
U.S. Beach Erosion Board
.
22.
Newman
,
J. N.
,
1996
, “Nonlinear Scattering of Long Waves by a Vertical Cylinder,”
Waves and Nonlinear Processes in Hydrodynamics
,
Fluid Mechanics and Its Applications
,
J.
Grue
,
B.
Gjevik
, and
J. E.
Weber
, eds.,
Springer
Netherlands
, pp.
91
102
.
23.
Malenica
,
S.
, and
Molin
,
B.
,
1995
, “
Third-Harmonic Wave Diffraction by a Vertical Cylinder
,”
J. Fluid Mech.
,
302
, pp.
203
229
.
24.
Huseby
,
M.
, and
Grue
,
J.
,
2000
, “
An Experimental Investigation of Higher-Harmonic Wave Forces on a Vertical Cylinder
,”
J. Fluid Mech.
,
414
, pp.
75
103
.
25.
Rainey
,
R. C. T.
,
1989
, “
A New Equation for Calculating Wave Loads on Offshore Structures
,”
J. Fluid Mech.
,
204
, pp.
295
324
.
26.
Suja-Thauvin
,
L.
,
Bachynski
,
E. E.
,
Pierella
,
F.
,
Borg
,
M.
,
Krokstad
,
J. R.
, and
Bredmose
,
H.
,
2020
, “
Critical Assessment of Hydrodynamic Load Models for a Monopile Structure in Finite Water Depth
,”
Marine Struct.
,
72
, p.
102743
.
27.
Pierella
,
F.
,
Bredmose
,
H.
,
De Vaal
,
J. B.
,
Eliassen
,
L.
,
Krokstad
,
J.
,
Anders Nygaard
,
T.
,
Oggiano
,
L.
, and
Stenbro
,
R.
,
2018
, “
The Dimensioning Sea Loads (DIMSELO) Project
,”
J. Phys.: Conf. Ser.
,
1104
, p.
012037
.
28.
Krokstad
,
J. R.
,
Stansberg
,
C. T.
,
Nestegård
,
A.
, and
Marthinsen
,
T.
,
1998
, “
A New Nonslender Ringing Load Approach Verified Against Experiments
,”
ASME J. Offshore Mech. Arct. Eng.
,
120
(
1
), pp.
20
29
.
29.
Bihs
,
H.
,
Wang
,
W.
,
Pakozdi
,
C.
, and
Kamath
,
A.
,
2020
, “
REEF3d::FNPF—A Flexible Fully Nonlinear Potential Flow Solver
,”
ASME J. Offshore Mech. Arct. Eng.
,
142
(
4
), p.
041902
.
30.
Kristiansen
,
T.
,
Bachynski
,
E. E.
,
Bickert
,
F.
,
Hniche
,
A.
,
Kocher
,
V.
, and
Liandrat
,
A.
,
2017
, “
Aspects in Model Testing of a Monopile in Steep Waves
,”
Volume 1: Offshore Technology
,
Trondheim, Norway
,
June 25–30
,
ASME
, p.
V001T01A051
.
31.
Li
,
L.
,
Gao
,
Z.
, and
Moan
,
T.
,
2015
, “
Joint Distribution of Environmental Condition at Five European Offshore Sites for Design of Combined Wind and Wave Energy Devices
,”
ASME J. Offshore Mech. Arct. Eng.
,
137
(
3
), p.
031901
.
32.
Leroy
,
V.
,
Bachynski-Polić
,
E. E.
,
Babarit
,
A.
,
Ferrant
,
P.
, and
Gilloteaux
,
J. C.
,
2021
, “
A Weak-Scatterer Potential Flow Theory-Based Model for the Hydroelastic Analysis of Offshore Wind Turbine Substructures
,”
Ocean Eng.
,
238
, p.
109702
.
33.
Pákozdi
,
C.
,
Spence
,
S.
,
Fouques
,
S.
,
Thys
,
M.
,
Alsos
,
H. S.
,
Bachynski
,
E. E.
,
Bihs
,
H.
, and
Kamath
,
A.
,
2018
, “
Nonlinear Wave Load Models for Extra Large Monopiles
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
San Francisco, CA
,
Nov. 4–7
,
American Society of Mechanical Engineers Digital Collection
, p. V001T01A033.
34.
Pakozdi
,
C.
,
Wang
,
W.
,
Kamath
,
A.
, and
Bihs
,
H.
,
2021
, “
Reduction of the Wave Propagation Error of a Sigma Grid Based Numerical Tank Using a Vertical Spacing Based on the Constant Truncation Error
,”
Ocean Eng.
,
239
, p.
109741
.
35.
Pakozdi
,
C.
,
Fouques
,
S.
,
Thys
,
M.
,
Kamath
,
A.
,
Wang
,
W.
,
Dadmarzi
,
F. H.
,
Bachynski
,
E.
, and
Bihs
,
H.
,
2020
, “
Validation of Numerical Wave Tank Simulations Using REEF3d With JONSWAP Spectra in Intermediate Water Depth
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
Virtual Online
,
Aug. 3–7
, pp.
1
12
.
36.
Baquet
,
A.
,
Kim
,
J.
, and
Huang
,
Z. J.
,
2017
, “
Numerical Modeling Using CFD and Potential Wave Theory for Three-Hour Nonlinear Irregular Wave Simulations
,”
Volume 1: Offshore Technology
,
Trondheim, Norway
,
June 25–30
,
American Society of Mechanical Engineers
, p.
V001T01A002
.
37.
Pakozdi
,
C.
,
Kamath
,
A.
,
Wang
,
W.
, and
Bihs
,
H.
,
2020
, “
Representation of Breaking Wave Kinematics in the Fully Nonlinear Potential Flow Model REEF3d::FNPF
,”
International Conference on Offshore Mechanics and Arctic Engineering
,
Virtual, Online
,
Aug. 3–7
, p.
V008T08A011
.
38.
Ikeda
,
Y.
,
Osa
,
K.
, and
Tanaka
,
N.
,
1988
, “
Viscous Forces Acting on Irregularly Oscillating Circular Cylinders and Flat Plates
,”
ASME J. Offshore Mech. Arct. Eng.
,
110
(
2
), pp.
140
147
.
39.
“RIFLEX Theory Manual,” 2012.
40.
Hansen
,
H. F.
,
Lohmann
,
I. P.
,
Sørensen
,
J. T.
, and
Schlütter
,
F.
,
2012
, “
A Model for Long-Term Distribution of Wave Induced Loads in Steep and Breaking Shallow Water Waves
,”
Volume 2: Structures, Safety and Reliability
,
Rio de Janeiro, Brazil
,
July 1–6
,
American Society of Mechanical Engineers
, pp.
685
693
.
41.
Goda
,
Y.
,
2010
, “
Reanalysis of Regular and Random Breaking Wave Statistics
,”
Coastal Eng. J.
,
52
(
1
), pp.
71
106
.
42.
Suja-Thauvin
,
L.
,
Krokstad
,
J. R.
, and
Bachynski
,
E. E.
,
2018
, “
Critical Assessment of Non-Linear Hydrodynamic Load Models for a Fully Flexible Monopile Offshore Wind Turbine
,”
Ocean Eng.
,
164
, pp.
87
104
.
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