Horizontal axis tidal turbines (HATTs) working in a complex flow environment will encounter unsteady streamwise flow conditions that affect their power generation and structural loads, where power fluctuations determine the quality of electricity generation, directly affecting the grid and reliability of the power transmission system; fatigue loads affect various structures and mechanical components of the turbine, directly determining the lifespan and reliability of the turbine. To gain insight into the generation mechanism and distribution of these excitations, a large eddy simulation is employed to analyze the inflow turbulence and unsteady forces excitations by a three-blade HATT. A spectral synthesizer was used to generate incoming turbulence flow. The strip method was applied on the HATT by dividing the blade into 20 strips. The thrust received by each strip and the flow velocity upstream and downstream of the blade's root, middle, and tip were monitored. The distribution of unsteady loads on the blades was analyzed, as well as the relationship between flow velocity upstream and downstream of the blade and the unsteady characteristics of the blades. The simulation results show that the unsteady hydrodynamic fluctuations of the HATT blades reach up to 57.44% under a turbulent intensity of 10%. Through intuitive analysis of flow separation on the suction surface of the blade at various moments under a low tip speed ratio, we can comprehend the variations in inflow velocity and flow separation on the blade surface. Analyzing the distribution of blade load from root to tip reveals that the maximum load values are concentrated in the 14th–16th strips, corresponding to the region from 0.7R to 0.8R. Moreover, the middle and tip sections of the blades predominantly contribute to the harmonics of the 3BPF (blade passing frequency) and broadband, with the middle section making a greater contribution. The tip section primarily contributes to harmonics above 3BPF. This research want to makes a valuable contribution to the comprehensive understanding of turbulence-induced exciting forces and the practical engineering design of HATT.

1.
Y.
Zhang
,
W.
Zang
,
J.
Zheng
,
L.
Cappietti
,
J.
Zhang
,
Y.
Zheng
et al, “
The influence of waves propagating with the current on the wake of a tidal stream turbine
,”
Appl. Energy
290
,
116729
(
2021
).
2.
X.
Liu
,
H.
Xu
,
B.
Wang
,
Y.
Wang
,
C.
Li
,
Y.
Si
et al, “
An analytical double-Gaussian wake model of ducted horizontal-axis tidal turbine
,”
Phys. Fluids
35
,
043103
(
2023
).
3.
X.
Liu
,
Z.
Chen
,
Y.
Si
,
P.
Qian
,
H.
Wu
,
L.
Cui
et al, “
A review of tidal current energy resource assessment in China
,”
Renewable Sustainable Energy Rev.
145
,
111012
(
2021
).
4.
Y.
Liu
,
H.
Zhe
,
Y.
Xue
,
J.
Tan
,
P.
Yuan
, and
Q.
Zhang
, “
Effects of vortex generator on the hydrodynamic characteristics of hydrofoil and horizontal axis tidal turbine
,”
Phys. Fluids
35
,
035104
(
2023
).
5.
G.
Li
and
W.
Zhu
, “
Tidal current energy harvesting technologies: A review of current status and life cycle assessment
,”
Renewable Sustainable Energy Rev.
179
,
113269
(
2023
).
6.
Y.
Si
,
X.
Liu
,
T.
Wang
,
B.
Feng
,
P.
Qian
,
Y.
Ma
et al, “
State-of-the-art review and future trends of development of tidal current energy converters in China
,”
Renewable Sustainable Energy Rev.
167
,
112720
(
2022
).
7.
C.
Li
,
Y.
Zhang
,
Y.
Zheng
,
Y.
Qian
,
H.
Hua
,
S.
Ren
et al, “
Effects of surge and roll motion on a floating tidal turbine using the actuator-line method
,”
Phys. Fluids
35
,
075125
(
2023
).
8.
S.
Walker
and
P. R.
Thies
, “
A review of component and system reliability in tidal turbine deployments
,”
Renewable Sustainable Energy Rev.
151
,
111495
(
2021
).
9.
G.
Thomas Scarlett
and
I. M.
Viola
, “
Unsteady hydrodynamics of tidal turbine blades
,”
Renewable Energy
146
,
843
855
(
2020
).
10.
A. D.
Heathershaw
, “
The turbulent structure of the bottom boundary layer in a tidal current
,”
Geophys. J. Int.
58
,
395
430
(
1979
).
11.
T. C. L.
Fava
,
B. A.
Lobo
,
P. A. S.
Nogueira
,
A. P.
Schaffarczyk
,
M.
Breuer
,
D. S.
Henningson
et al, “
Numerical study of the hydrodynamic stability of a wind-turbine airfoil with a laminar separation bubble under free-stream turbulence
,”
Phys. Fluids
35
,
084104
(
2023
).
12.
J.
Peinke
,
S.
Barth
,
F.
Böttcher
,
D.
Heinemann
, and
B.
Lange
, “
Turbulence, a challenging problem for wind energy
,”
Physica A
338
,
187
193
(
2004
).
13.
W.
Li
,
H.
Zhou
,
H.
Liu
,
Y.
Lin
, and
Q.
Xu
, “
Review on the blade design technologies of tidal current turbine
,”
Renewable Sustainable Energy Rev.
63
,
414
422
(
2016
).
14.
P.
Veers
,
K.
Dykes
,
E.
Lantz
,
S.
Barth
,
C. L.
Bottasso
,
O.
Carlson
et al, “
Grand challenges in the science of wind energy
,”
Science
366
,
eaau2027
(
2019
).
15.
P.
Druault
and
J. F.
Krawczynski
, “
Numerical investigation of the spatial integration effect on the velocity spectrum: Consequences in the wind or tidal turbine power spectrum
,”
Comput. Fluids
250
,
105729
(
2023
).
16.
M.
Melius
,
R. B.
Cal
, and
K.
Mulleners
, “
Dynamic stall of an experimental wind turbine blade
,”
Phys. Fluids
28
,
034103
(
2016
).
17.
U.
Ahmed
,
D. D.
Apsley
,
I.
Afgan
,
T.
Stallard
, and
P. K.
Stansby
, “
Fluctuating loads on a tidal turbine due to velocity shear and turbulence: Comparison of CFD with field data
,”
Renewable Energy
112
,
235
246
(
2017
).
18.
I. A.
Milne
, “
An experimental investigation of turbulence and unsteady loading on tidal turbines
,” Ph.D. thesis (
The University of Auckland
,
2014
), p.
257
.
19.
I. A.
Milne
,
R. N.
Sharma
,
R. G. J.
Flay
, and
S.
Bickerton
, “
The role of onset turbulence on tidal turbine blade loads
,” in
17th Australasian Fluid Mechanics Conference 2010
(University of Auckland,
2010
), pp.
444
447
.
20.
I. A.
Milne
,
A. H.
Day
,
R. N.
Sharma
, and
R. G. J.
Flay
, “
Blade loading on tidal turbines for uniform unsteady flow
,”
Renewable Energy
77
,
338
350
(
2015
).
21.
I. A.
Milne
,
A. H.
Day
,
R. N.
Sharma
, and
R. G. J.
Flay
, “
Blade loads on tidal turbines in planar oscillatory flow
,”
Ocean Eng.
60
,
163
174
(
2013
).
22.
I. A.
Milne
,
A. H.
Day
,
R. N.
Sharma
, and
R. G. J.
Flay
, “
The characterisation of the hydrodynamic loads on tidal turbines due to turbulence
,”
Renewable Sustainable Energy Rev.
56
,
851
864
(
2016
).
23.
M.
Allmark
,
R.
Ellis
,
T.
Ebdon
,
C.
Lloyd
,
S.
Ordonez-Sanchez
,
R.
Martinez
et al, “
A detailed study of tidal turbine power production and dynamic loading under grid generated turbulence and turbine wake operation
,”
Renewable Energy
169
,
1422
1439
(
2021
).
24.
M.
Slama
,
G.
Pinon
,
C.
El Hadi
,
M.
Togneri
,
B.
Gaurier
,
G.
Germain
et al, “
Turbine design dependency to turbulence: An experimental study of three scaled tidal turbines
,”
Ocean Eng.
234
,
109035
(
2021
).
25.
T.
Blackmore
,
L. E.
Myers
, and
A. S.
Bahaj
, “
Effects of turbulence on tidal turbines: Implications to performance, blade loads, and condition monitoring
,”
Int. J. Mar. Energy
14
,
1
26
(
2016
).
26.
T.
Blackmore
,
B.
Gaurier
,
L.
Myers
,
G.
Germain
, and
A. S.
Bahaj
, “
The effect of freestream turbulence on tidal turbines
,” in
11th European Wave and Tidal Energy Conference, Nantes, France
,
2015
.
27.
W. H.
Lam
and
L.
Chen
, “
Equations used to predict the velocity distribution within a wake from a horizontal-axis tidal-current turbine
,”
Ocean Eng.
79
,
35
42
(
2014
).
28.
I.
Afgan
,
J.
McNaughton
,
S.
Rolfo
,
D. D.
Apsley
,
T.
Stallard
, and
P.
Stansby
, “
Turbulent flow and loading on a tidal stream turbine by LES and RANS
,”
Int. J. Heat Fluid Flow
43
,
96
108
(
2013
).
29.
G.
Chen
,
X. B.
Li
, and
X. F.
Liang
, “
IDDES simulation of the performance and wake dynamics of the wind turbines under different turbulent inflow conditions
,”
Energy
238
,
121772
(
2022
).
30.
A.
Posa
and
R.
Broglia
, “
Characterization of the turbulent wake of an axial-flow hydrokinetic turbine via large-eddy simulation
,”
Comput. Fluids
216
,
104815
(
2021
).
31.
P.
Ouro
,
M.
Harrold
,
T.
Stoesser
, and
P.
Bromley
, “
Hydrodynamic loadings on a horizontal axis tidal turbine prototype
,”
J. Fluids Struct.
71
,
78
95
(
2017
).
32.
R.
Su
,
Z.
Gao
,
Y.
Chen
,
C.
Zhang
, and
J.
Wang
, “
Large-eddy simulation of the influence of hairpin vortex on pressure coefficient of an operating horizontal axis wind turbine
,”
Energy Convers. Manage.
267
,
115864
(
2022
).
33.
W.
Finnegan
,
E.
Fagan
,
T.
Flanagan
,
A.
Doyle
, and
J.
Goggins
, “
Operational fatigue loading on tidal turbine blades using computational fluid dynamics
,”
Renewable Energy
152
,
430
440
(
2020
).
34.
J. M. R.
Graham
, “
Rapid distortion of turbulence into an open turbine rotor
,”
J. Fluid Mech.
825
,
764
794
(
2017
).
35.
L. P.
Chamorro
,
C.
Hill
,
S.
Morton
,
C.
Ellis
,
R. E. A.
Arndt
, and
F.
Sotiropoulos
, “
On the interaction between a turbulent open channel flow and an axial-flow turbine
,”
J. Fluid Mech.
716
,
658
670
(
2013
).
36.
H.
Liu
,
Y.
Jin
,
N.
Tobin
, and
L. P.
Chamorro
, “
Towards uncovering the structure of power fluctuations of wind farms
,”
Phys. Rev. E
96
,
063117
(
2017
).
37.
O.
Durán Medina
,
F. G.
Schmitt
,
R.
Calif
,
G.
Germain
, and
B.
Gaurier
, “
Turbulence analysis and multiscale correlations between synchronized flow velocity and marine turbine power production
,”
Renewable Energy
112
,
314
327
(
2017
).
38.
L. P.
Chamorro
,
S.-J.
Lee
,
D.
Olsen
,
C.
Milliren
,
J.
Marr
,
R. E.
Arndt
et al, “
Turbulence effects on a full-scale 2.5 MW horizontal-axis wind turbine under neutrally stratified conditions
,”
Wind Energy
18
,
339
349
(
2015
).
39.
N.
Tobin
,
H.
Zhu
, and
L. P.
Chamorro
, “
Spectral behaviour of the turbulence-driven power fluctuations of wind turbines
,”
J. Turbul.
16
,
832
846
(
2015
).
40.
G.
Deskos
,
G. S.
Payne
,
B.
Gaurier
, and
M.
Graham
, “
On the spectral behaviour of the turbulence-driven power fluctuations of horizontal-axis turbines
,”
J. Fluid Mech.
904
,
A13
(
2020
).
41.
J.
Apt
, “
The spectrum of power from wind turbines
,”
J. Power Sources
169
,
369
374
(
2007
).
42.
F.
Paraz
and
M. M.
Bandi
, “
Second order structure functions for higher powers of turbulent velocity
,”
J. Phys.: Condens. Matter
31
,
484001
(
2019
).
43.
W.
Katzenstein
,
E.
Fertig
, and
J.
Apt
, “
The variability of interconnected wind plants
,”
Energy Policy
38
,
4400
4410
(
2010
).
44.
B.
Gaurier
,
M.
Ikhennicheu
,
G.
Germain
, and
P.
Druault
, “
Experimental study of bathymetry generated turbulence on tidal turbine behaviour
,”
Renewable Energy
156
,
1158
1170
(
2020
).
45.
L. P.
Chamorro
,
C.
Hill
,
V. S.
Neary
,
B.
Gunawan
,
R. E. A.
Arndt
, and
F.
Sotiropoulos
, “
Effects of energetic coherent motions on the power and wake of an axial-flow turbine
,”
Phys. Fluids
27
,
055104
(
2015
).
46.
P.
Druault
,
B.
Gaurier
, and
G.
Germain
, “
Spatial integration effect on velocity spectrum: Towards an interpretation of the −11/3 power law observed in the spectra of turbine outputs
,”
Renewable Energy
181
,
1062
1080
(
2022
).
47.
L.
Perez
,
R.
Cossu
,
A.
Grinham
, and
I.
Penesis
, “
An investigation of tidal turbine performance and loads under various turbulence conditions using Blade Element Momentum theory and high-frequency field data acquired in two prospective tidal energy sites in Australia
,”
Renewable Energy
201
,
928
937
(
2022
).
48.
S. A.
El-Shahat
,
G.
Li
, and
L.
Fu
, “
Dynamic loading characterization of a horizontal axis tidal current turbine
,”
Ocean Eng.
211
,
107561
(
2020
).
49.
S. A.
El-Shahat
,
L.
Fu
, and
G.
Li
, “
Linear and non-linear wave theories coupled with a modified BEM model for quantifying dynamic loads of a tidal stream turbine
,”
Ocean Eng.
243
,
110334
(
2022
).
50.
L.
Perez
,
R.
Cossu
,
A.
Grinham
, and
I.
Penesis
, “
Tidal turbine performance and loads for various hub heights and wave conditions using high-frequency field measurements and Blade Element Momentum theory
,”
Renewable Energy
200
,
1548
1560
(
2022
).
51.
P.
Wang
,
L.
Wang
,
Q.
Zhang
,
F.
Zhu
, and
B.
Huang
, “
Performance and reliability study of China's first megawatt-scale horizontal-axis tidal turbine
,”
Appl. Ocean Res.
138
,
103648
(
2023
).
52.
H.
Yao
,
L.
Cao
,
D.
Wu
,
F.
Yu
, and
B.
Huang
, “
Generation and distribution of turbulence-induced forces on a propeller
,”
Ocean Eng.
206
,
107255
(
2020
).
53.
Y.
Zhang
,
J.
Han
,
B.
Huang
,
D.
Zhang
, and
D.
Wu
, “
Excitation force on a pump-jet propeller: The effect of the blade number
,”
Ocean Eng.
281
,
114727
(
2023
).
54.
T. D.
Canonsburg
,
ANSYS Fluent Theory Guide
(
ANSYS Inc
,
2013
), p.
814
.
55.
P.
Ouro
,
L.
Ramírez
, and
M.
Harrold
, “
Analysis of array spacing on tidal stream turbine farm performance using large-eddy simulation
,”
J. Fluids Struct.
91
,
102732
(
2019
).
56.
X.
Liu
,
B.
Feng
,
D.
Liu
,
Y.
Wang
,
H.
Zhao
,
Y.
Si
et al, “
Study on two-rotor interaction of counter-rotating horizontal axis tidal turbine
,”
Energy
241
,
122839
(
2022
).
57.
R. H.
Kraichnan
, “
Diffusion by a random velocity field
,”
Phys. Fluids
13
,
22
31
(
1970
).
58.
A.
Smirnov
,
S.
Shi
, and
I.
Celik
, “
Random flow generation technique for large eddy simulations and particle-dynamics modeling
,”
J. Fluids Eng. Trans. ASME
123
,
359
371
(
2001
).
59.
N. J.
Wei
and
J. O.
Dabiri
, “
Power-generation enhancements and upstream flow properties of turbines in unsteady inflow conditions
,”
J. Fluid Mech.
966
,
A30
(
2023
).
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