Floating wind turbines: the future of wind energy?€¦ · · 2017-06-27Samsung S7.0-171 83.5 m...
Transcript of Floating wind turbines: the future of wind energy?€¦ · · 2017-06-27Samsung S7.0-171 83.5 m...
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Floating wind turbines: the future of wind energy?
Axelle Viré Faculty of Aerospace Engineering [email protected]
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Outline
• Trends in (offshore) wind energy • Concepts of floating wind turbines • Some challenges • Research in the field at LR
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Scale-up success
’85 87 89 91 93 95 97 99 01 03 05 07 09 11 13 15
.05 . 3 . 5 1.3 1.6 2 4.5 5 7.5 8 MW
33 m Ø
171 m Ø
126 m Ø
A380 Airbus
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Cumulative wind power installations in Europe (GW)
Wind in power – 2015 European Statistics, EWEA report (Feb. 2016)
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Cumulative wind power installations offshore in Europe (MW)
The European offshore wind industry - key trends and statistics 2015, EWEA report (Feb. 2016)
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Types of foundations
Newly installed foundations in Europe in 2015 • 97% monopiles (385 structures) • 3% jackets (12 structures) In 2015, there were 3,313 foundations installed offshore in Europe
97%
3%
97%
3%
Monopile: www.londonarray.com (May, 2016) Jacket: Alpha Ventus, www.offshorewind.biz (May, 2016)
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Limitations of current technology
Most seas are deeper than 50 metres Existing commercial foundations are not economically viable in deep seas
Source: N
. Anscombe
, Turbines take flo
at, Pow
er Engineer, Vo
l. 18, Issue
3 (2
004)
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Main types of foundation
Tension leg platform Semi-submersible Spar buoy
Stability Moorings Buoyancy Ballast Assembly Dry dock Dry dock On/off-shore Installation Towing to site Towing to site Towing or not Depth 50-150 m 50-150 m 100m - ?
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Recent developments
2008 – Blue H (80kW)
hSp://www.bluehengineering.com/historical-‐development.html
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Recent developments
2009 – Hywind (2.3MW) Upcoming– Hywind Scotland Pilot Park (30MW)
www.statoil.com/HywindScotland
Photo: Trude Refsahl/Statoil
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Recent developments
2011 – WindFloat (2MW) Upcoming – WindFloat Atlan\c (25MW)
hSp://www.principlepowerinc.com/en/windfloat
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Recent developments
2011-‐2016 – Fukushima Forward project (2MW, 5MW, 7MW)
hSp://www.fukushima-‐forward.jp
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Some challenges
• Turbine – Rotor-wake interactions – Control systems
• Support structure – Conservatism in the design (not cost effective) – Relation between size of turbine rating
• Mooring lines – Dynamic behaviour of moorings, esp. in shallow water – Anchors and soil conditions
• Electrical infrastructure – Dynamic power cables
• Operation and maintenance – Harsh environmental conditions
• Design standards – Lack of experience leads to conservative designs – Modelling of the system dynamics
Technologically feasible but needs to be cheaper!
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Numerical modelling
Accuracy
Cost
CFD & FEM
Aero-servo- hydro-elastic
coupling
Reduced modeling Pre-design
Design validation
Detailed design
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High-fidelity modelling of FSI
Unstructured mesh fluid/ocean model (finite elements)
Fluidity training workshop Nov 2011 – A brief introduction to numerical simulation & Fluidity – Matthew Piggott
© Imperial College London Page 17
A highly multi-scale example: astronomically forced M2 tide in the North Atlantic coupled to the North and Baltic Seas A high resolution mesh is required to resolve the channels connecting the Baltic and North Seas but a much coarser mesh is acceptable in the North Atlantic More than two orders of magnitude difference between coarsest and finest resolutions
hSp://fluidityproject.github.io
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Applications
• Wind/tidal turbine modelling through actuator disks – Abolghasemi et al. “Simulating tidal turbines with multi-scale mesh optimisation techniques”,
Journal of Fluids and Structures 66:69-90 (2016) – Viré et al. “Towards the fully-coupled numerical modelling of floating wind turbines”, Energy
Procedia 35:43-51 (2013)
• Dynamics of a floating monopile – Viré et al. “Towards the fully-coupled numerical modelling of floating wind turbines”, Energy
Procedia 35:43-51 (2013)
• Aerodynamics of kite wings – Rajan et al. “Fluid-structure interaction of an inflatable kite wing”, Airborne Wind Energy
Conference (2015)
• Wave-structure interactions
– Viré et al. “Application of the immersed-body method to simulate wave-structure interactions”, European Journal of Mechanics B/Fluids 55:330-339 (2016)
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Applications
• Wind/tidal turbine modelling through actuator disks – Abolghasemi et al. “Simulating tidal turbines with multi-scale mesh optimisation techniques”,
Journal of Fluids and Structures 66:69-90 (2016) – Viré et al. “Towards the fully-coupled numerical modelling of floating wind turbines”, Energy
Procedia 35:43-51 (2013)
• Dynamics of a floating monopile – Viré et al. “Towards the fully-coupled numerical modelling of floating wind turbines”, Energy
Procedia 35:43-51 (2013)
• Aerodynamics of kite wings – Rajan et al. “Fluid-structure interaction of an inflatable kite wing”, Airborne Wind Energy
Conference (2015)
• Wave-structure interactions
– Viré et al. “Application of the immersed-body method to simulate wave-structure interactions”, European Journal of Mechanics B/Fluids 55:330-339 (2016)
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Wave-structure interactions
• Regular waves of steepness where and • Intermediate water depth: ( ) • Inviscid flow Reference: linear wave theory (MacCamy & Fuchs, 1954)
ak = 0.01gk tanh(kh) = (2⇡T )2 T = 1
h/�0 = 0.45 �0 = 2⇡g/!2
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Wave-structure interactions
0 5 10 15 20
−1
−0.5
0
0.5
1
x/h
η/a
0 5 10 15 20
−1
−0.5
0
0.5
1
x/h
η/a
Theoretical solution Defined-body approach Immersed-body approach
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Wave-structure interactions
• Irregular waves • Amplitudes of the focused wave ( is the Jonswap peak) • The amplitude is maximum at: and Reference: second-order calculation (Sharma & Dean, 1981)
Asumkp = 0.018 Asumkp = 0.09kp
xf = 10h tf = 7.5T
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Wave-structure interactions
8 9 10 11 12
−0.5
0
0.5
1
t/Tp
η/Asum
8 9 10 11 12
−0.5
0
0.5
1
t/Tp
η/Asum
CFD Second-order solution
Asumkp = 0.018 Asumkp = 0.09
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Wave-structure interactions
With defined pile Without pile
6 7 8 9−1
−0.5
0
0.5
1
t/Tp
η/η⋆max
6 7 8 9−1
−0.5
0
0.5
1
t/Tp
η/η⋆max
Asumkp = 0.018 Asumkp = 0.09
With immersed pile
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Wave-structure interaction
0 2 4 6 8 10 12 14−0.3
−0.1
0.1
0.3
0.5
0.7
t∗
F ∗|body
Immersed bodyHu et al. (num)Hu et al. (exp)
1.4 1.6 1.8 2 2.2 2.40.3
0.4
0.5
0.6
0.7
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Upcoming works
• CFD modelling of the TetraSpar concept (Stiesdal, 2016), with Deltares and NTNU
• Re-design of blades for model-scale testing, with MARIN
• Build synergies at TU Delft and internationally on floating wind energy
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The future of wind energy?
Market study floa\ng wind in the Netherlands, TKI Wind Op Zee (Nov. 2015)
Cost comparison for a wind farm of 800 MW installed capacity