# Integrated System Design for a Large Wind Turbine Supported on a Moored Semi-Submersible Platform

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## Abstract

**:**

## 1. Introduction

- Shallow-draft platforms, such as barges with catenary mooring lines, that achieve stability via the extent of their water-plane area.
- Deep-draft platforms, such as spars with moored catenary or taut lines, that achieve stability and pitch-restoring moment via ballast.
- Buoyancy-driven platforms, such as tension-leg platforms (TLPs), that achieve stability via a series of mooring lines in tension.

## 2. SNL 13.2-MW Wind Turbine and OC4 DeepCwind Platform Baseline Models

#### 2.1. SNL 13.2-MW Baseline Turbine Properties

#### 2.2. Baseline Semi-Submersible Platform and Mooring System

## 3. Preliminary Model Development of SNL 13.2-MW Semi-Submersible FOWT

#### 3.1. Design Methodology

#### 3.2. Tower Model Development

#### 3.3. Platform and Mooring System Development

- NREL 5MW: NREL 5-MW land-based reference wind turbine model, hub height 90.0 m.
- SNL14602: SNL 13.2-MW land-based wind turbine model with SNL100-02 blades, hub height 146.0 m.
- SNL13302: SNL 13.2-MW land-based wind turbine model with SNL100-02 blades, hub height 133.5 m.

#### 3.3.1. Keulegan–Carpenter Number: Flow-Structure Interaction

#### 3.3.2. Platform Hydrodynamic Properties

#### 3.3.3. Free-Decay Simulation

## 4. Response Analysis of Integrated SNL 13.2-MW FOWT

#### 4.1. Response Amplitude Operators

#### 4.2. Steady-State Response of Integrated System under Uniform Wind and Regular Waves

#### 4.3. Selected Design Load Cases Analysis

#### 4.4. Dynamic Response Analysis under Turbulent Winds and Irregular Waves

## 5. Conclusions

- (i)
- An earlier semi-submersible platform model with a scale factor of 1.8 (on the OC4 model) for the 13.2-MW turbine was overdesigned. A more economical model with a scale factor of 1.5 for the platform and a mooring line scale factor of 2.0 was found to be adequate for the 13.2-MW wind turbine with SNL100-02 blades in stability and dynamic analyses.
- (ii)
- A new tower model was designed to support the wind turbine mounted on the semi-submersible platform. The tower height and thickness were chosen to meet design constraints such as an air gap or clearance requirement. A Campbell diagram analysis showed that the tower developed is in the soft-stiff design range and avoids resonance with important rotor rotation and blade-passing frequencies.
- (iii)
- Platform hydrodynamic properties were calculated using WAMIT, only considering linear hydrodynamic effects. KC numbers for several sea states were computed, and it was shown that the application of potential flow theory to this large-volume platform model can be justified. Computed hydrodynamic coefficients for the model developed are consistent with those for the OC4 DeepCwind model.
- (iv)
- The steady-state response of the integrated system showed that its behavior is satisfactory based on the design criteria. Static offsets in pitch and heave motions were in a reasonable range, and short-term maximum values were sufficiently low to help validate the model.
- (v)
- Response amplitude operators were generated for this integrated model in the time domain to account for nonlinear characteristics based on white-noise wave excitation using FAST. Response amplitudes are comparable with those for the OC4 DeepCwind model, but the dominant frequencies were somewhat lower, suggesting that this system is more sensitive to low-frequency forces.
- (vi)
- The performance of the integrated system under a turbulent wind field and irregular waves demonstrated its stability and satisfactory performance. Satisfactory pitch motion statistics including maxima, in the sea states studies, suggest that the model developed is adequate even for use in severe sea states.

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**Floating offshore wind turbine concepts [5].

**Figure 2.**Variation in mass density, flapwise stiffness and edgewise stiffness along the (normalized) length for three Sandia National Laboratories (SNL) 100-m blade designs and for the NREL 5-MW wind turbine blade.

**Figure 6.**Campbell diagram for the SNL 13.2-MW wind turbine with SNL100-02 blades and a 118.5-m tower.

**Figure 7.**Keulegan–Carpenter (KC) numbers for the SNL semi-submersible platform: (

**a**) for the main column at normal sea states; (

**b**) for the offset column at normal sea states; (

**c**) for the main column at 50-year return sea states; (

**d**) for the offset column at 50-year return sea states.

**Figure 9.**SNL semi-submersible platform added mass and radiation damping coefficients for a zero wave heading.

**Figure 11.**Integrated system showing the Sandia 13.2-MW wind turbine, tower, semi-submersible floating platform and mooring lines.

**Figure 12.**Heave free-decay simulation of the integrated system model following an initial heave displacement of 2 m: (

**a**) Modes 1, 2 and 3; (

**b**) Modes 4, 5 and 6.

**Figure 13.**RAOs under zero wind speed: (

**a**) for the SNL 13.2 MW model; (

**b**) for the OC4 DeepCwind model.

**Figure 14.**Time series of the integrated system for a unit-amplitude wave at a surge natural frequency of 0.0057 Hz (for rated wind velocity, ${V}_{rated}=11.3$ m/s).

**Figure 15.**One-hour time series of the SNL 13.2-MW turbine-platform integrated system under different sea states: (

**a**) ${V}_{hub}$ = 11.3 m/s, ${H}_{s}$ = 7.77 m, ${T}_{p}$ = 14.43 s; (

**b**) ${V}_{hub}$ = 25.0 m/s, ${H}_{s}$ = 11.52 m, ${T}_{p}$ = 14.31 s.

Blade Designation | SNL100-00 | SNL100-01 | SNL100-02 | SNL100-03 |
---|---|---|---|---|

Material | all-glass baseline blade | carbon design | advanced core material | advanced geometry |

Blade Weight (kg) | 114,172 | 73,995 | 59,047 | 49,519 |

Span-wise CG(m) | 33.6 | 33.1 | 31.95 | 31.55 |

Fixed-base ${f}_{n}$ (Hz) | 0.42 | 0.49 | 0.55 | 0.49 |

Parameter | Value | Parameter | Value | Parameter | Value |
---|---|---|---|---|---|

Rated Power | 13.2 MW | Rotor Orientation | Upwind | Blade Designation | SNL100-02 |

Rotor Dia. | 205 m | Hub Dia. | 5 m | Blade Length | 100 m |

Hub Height | 133.5 m | Generator Eff. | 94.40% | No. of Blades | 3 |

${V}_{in}$ | 3 m/s | Cut-in Rotor Speed | 4.34 rpm | Blade Weight | 59,047 kg |

${V}_{rated}$ | 11.3 m/s | Rated Rotor Speed | 7.44 rpm | Span-wise CGloc. | 31.95 m |

${V}_{out}$ | 25 m/s | Rated Tip-speed | 80 m/s | Maximum Chord | 7.63 m |

Overhang | 8.16 m | Rotor Mass | 422,131 kg | Natural Frequency | 0.55 Hz |

Precone | 2.5 deg | Tower Mass | 553,995 kg | Control System:Variable-speed; Collective-pitch | |

Shaft Tilt | 5 deg | Tower-top Mass | 1,452,131 kg |

**Table 3.**The OC4-DeepCwind floating system geometry and structural properties. SWL, still water level; CM, center of mass.

Static Properties | Values | Multiplication Factor |
---|---|---|

Depth of platform base below SWL | 20 m | $\lambda $ |

Elevation of main column above SWL | 10 m | |

Elevation of offset columns above SWL | 12 m | |

Spacing between offset columns | 50 m | |

Length of upper columns | 26 m | |

Length of base columns | 6 m | |

Depth to top of base columns below SWL | 14 m | |

Diameter of main column | 6.5 m | |

Diameter of offset (upper) columns | 12 m | |

Diameter of base columns | 24 m | |

Diameter of pontoons and cross braces | 1.6 m | |

CM location below SWL | 13.46 m | |

Platform mass, including ballast | 1.3473 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{7}$ kg | ${\lambda}^{3}$ |

Platform roll inertia about CM | 6.827 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{9}$ kg-m${}^{2}$ | ${\lambda}^{5}$ |

Platform pitch inertia about CM | 6.827 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{9}$ kg-m${}^{2}$ | |

Platform yaw inertia about CM | 1.226 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{10}$ kg-m${}^{2}$ |

Parameters | Values | Multiplication Factor |
---|---|---|

Number of Mooring Lines | 3 | (−) |

Angle Between Adjacent Lines | 120 | (−) |

Depth to Anchors Below SWL | 200 m | (−) |

Depth to Fairleads Below SWL | 14 m | ${\lambda}_{P}$ |

Radius to Anchors from Platform Centerline | 837.6 m | (−) |

Radius to Fairleads from Platform Centerline | 40.868 m | $\lambda $ |

Unstretched Mooring Line Length | 835.5 m | (−) |

Mooring Line Diameter | 0.0766 m | $\lambda $ |

Equivalent Mooring Line Mass Density | 113.35 kg/m | ${\lambda}^{2}$ |

Equivalent Mooring Line Mass in Water | 108.63 kg/m | ${\lambda}^{2}$ |

Equivalent Mooring Line Extensional Stiffness | 753.6 MN | ${\lambda}^{2}$ |

Hydrodynamic Drag Coefficient for Mooring Lines | 1.1 | (−) |

Hydrodynamic Added-Mass Coefficient for Mooring Lines | 1.0 | (−) |

Seabed Drag Coefficient For Mooring Lines | 1.0 | (−) |

Structural Damping of Mooring Lines | 2.0% | (−) |

(−) indicates t parameter is not changed (relative to OC4 DeepCwind). |

Physical Parameter | Units | Scale Factor |
---|---|---|

Length | m | $\lambda $ |

Structural mass | kg | ${\lambda}^{3}$ |

Force | N | ${\lambda}^{3}$ |

Moment | N-m | ${\lambda}^{4}$ |

Acceleration | m/s${}^{2}$ | 1 |

Time | s | $\sqrt{\lambda}$ |

Pressure | Pa or N/m${}^{2}$ | $\lambda $ |

**Table 6.**Distributed geometric and structural properties for the 115.6-m tower for the SNL 13.2 MW wind turbine.

Elevation (m) | HtFract (−) | TMassDen (kg/m) | TwFAStif (N-m${}^{2}$) | TwSSStif (N-m${}^{2}$) | TwGJStif (N-m${}^{2}$) | TwEAStif (N) | TwFAIner (kg-m) | TwSSIner (kg-m) |
---|---|---|---|---|---|---|---|---|

0.00 | 0.0 | 7010.24 | 2.05 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 2.05 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.57 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.73 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 82,841.3 | 82,841.3 |

11.46 | 0.1 | 6527.08 | 1.75 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.75 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.35 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.61 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 71,011.8 | 71,011.8 |

22.92 | 0.2 | 6060.75 | 1.49 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.49 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.15 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.50 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 60,490.5 | 60,490.5 |

34.38 | 0.3 | 5611.23 | 1.26 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.26 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 9.73 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.39 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 51,177.7 | 51,177.7 |

45.84 | 0.4 | 5178.54 | 1.06 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.06 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 8.17 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{12}$ | 1.28 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 42,977.8 | 42,977.8 |

57.30 | 0.5 | 4762.67 | 8.84 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 8.84 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 6.81 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 1.18 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 35,799.1 | 35,799.1 |

68.76 | 0.6 | 4363.62 | 7.30 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 7.30 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 5.62 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 1.08 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 29,553.6 | 29,553.6 |

80.22 | 0.7 | 3981.39 | 5.97 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 5.97 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 4.59 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 9.84 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{10}$ | 24,157.5 | 24,157.5 |

91.68 | 0.8 | 3615.98 | 4.83 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 4.83 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 3.71 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 8.93 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{10}$ | 19,530.8 | 19,530.8 |

103.14 | 0.9 | 3267.39 | 3.85 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 3.85 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 2.97 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 8.07 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{10}$ | 15,597.3 | 15,597.3 |

114.60 | 1.0 | 2935.63 | 3.04 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 3.04 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 2.34 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{11}$ | 7.25$\times {10}^{10}$ | 12,284.9 | 12,284.9 |

Model | ${\mathit{F}}_{5}$ (kN-m) | ${\mathit{C}}_{55}^{\mathit{r}}$ (kN-m/rad) | ${\mathit{C}}_{55}^{{\mathbf{\lambda}}_{\mathit{P}}}$ (kN-m/rad) | R | ${\mathbf{\lambda}}_{\mathit{P}}$ | Remarks |
---|---|---|---|---|---|---|

NREL 5MW | 5.27 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{4}$ | 3.02 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 3.80 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 1.26 | 1 | (−) |

SNL14602 | 2.81 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 1.61 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 3.99 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 2.48 | 1.8 | Ref. [16] |

1.46 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 0.91 | 1.4 | $R<1$, fails | |||

SNL13302 | 2.29 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 1.31 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 3.99 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 3.03 | 1.8 | $R\gg 1$, over-designed |

1.92 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 1.46 | 1.5 | $R>1$, OK | |||

1.46 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 1.11 | 1.4 | $R>1$, OK | |||

${F}_{5}$: tower-base out-of-plane bending moment; $R={C}_{55}^{{\lambda}_{P}}/{C}_{55}^{r}$ |

Models | SNL13302 | ||
---|---|---|---|

Scale Factor | 1.6 | 1.5 | 1.4 |

Total Mass (kg) | 2.46 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 2.02 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 1.65 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ |

Allowable Tower Mass, C (kg) | 1.00 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{6}$ | 5.72 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 1.94 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ |

Actual Tower Mass, D (kg) | 5.86 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 5.54 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ | 5.21 $\times \phantom{\rule{3.33333pt}{0ex}}{10}^{5}$ |

Remarks | $D\ll C$, over-designed | $C\simeq D$ OK | $D\gg C$, fails |

**Table 9.**Sea states defined by wave spectral peak period, T, and significant wave height, ${H}_{s}$, selected for the dynamic analyses.

Sea States | Normal | 50-Year Return | ||
---|---|---|---|---|

T (s) | ${\mathit{H}}_{\mathit{s}}$ (m) | T (s) | ${\mathit{H}}_{\mathit{s}}$ (m) | |

1 | 2.0 | 0.09 | 14.83 | 5.91 |

2 | 4.8 | 0.67 | 14.65 | 6.55 |

3 | 6.5 | 1.40 | 14.51 | 7.22 |

4 | 8.1 | 2.44 | 14.41 | 7.94 |

5 | 9.7 | 3.66 | 14.35 | 8.71 |

6 | 11.3 | 5.49 | 14.32 | 9.51 |

7 | 13.6 | 9.14 | 14.3 | 10.35 |

8 | 17.0 | 15.24 | 14.31 | 11.52 |

Coefficients | Value |
---|---|

Added-mass coefficient (${C}_{a}$) for all members | 0.63 |

Added-mass coefficient (${C}_{az}$) for the base column in the z direction | 1.00 |

Drag coefficient (${C}_{d}$) for the main column | 0.56 |

Drag coefficient (${C}_{d}$) for the upper columns | 0.61 |

Drag coefficient (${C}_{d}$) for the base columns | 0.68 |

Drag coefficient (${C}_{d}$) for the pontoons and cross members | 0.63 |

Drag coefficient (${C}_{dz}$) for the base columns in the z direction | 4.80 |

V (m/s) | Low Wave Height | Medium Wave Height | High Wave Height | |||
---|---|---|---|---|---|---|

${\mathit{H}}_{\mathit{s}}$ (m) | ${\mathit{T}}_{\mathit{p}}$ (s) | ${\mathit{H}}_{\mathit{s}}$ (m) | ${\mathit{T}}_{\mathit{p}}$ (s) | ${\mathit{H}}_{\mathit{s}}$ (m) | ${\mathit{T}}_{\mathit{p}}$ (s) | |

9 | 1.0 | 7.0 | 2.5 | 8.0 | 4.0 | 9.5 |

12 | 1.0 | 6.0 | 2.5 | 7.0 | 4.0 | 8.5 |

16 | 2.0 | 8.0 | 3.5 | 8.5 | 5.0 | 10.5 |

No | Sea State | TwrBsMyt (kN-m) | PtfmSurge (m) | PtfmHeave (m) | PtfmPitch (Deg) | TFair [1] (kN) | |
---|---|---|---|---|---|---|---|

V | ${\mathit{H}}_{\mathit{s}}$, ${\mathit{T}}_{\mathit{p}}$ | ||||||

1 | 9 | 1.0, 7.0 | 2.63$\times {10}^{5}$ | 13.5 | −0.03 | 1.95 | 3106 |

2 | 2.5, 8.0 | 3.17$\times {10}^{5}$ | 13.6 | −00.07 | 2.02 | 3112 | |

3 | 4.0, 9.5 | 3.33$\times {10}^{5}$ | 13.7 | −00.15 | 2.24 | 3120 | |

4 | 12 | 1.0, 6.0 | 3.04$\times {10}^{5}$ | 19.3 | −00.05 | 2.45 | 3833 |

5 | 2.5, 7.0 | 3.58$\times {10}^{5}$ | 16.0 | −00.07 | 2.35 | 3387 | |

6 | 4.0, 8.5 | 4.02$\times {10}^{5}$ | 15.4 | −00.12 | 2.49 | 3323 | |

7 | 16 | 2.0, 8.0 | 2.51$\times {10}^{5}$ | 11.2 | 0.06 | 1.58 | 2875 |

8 | 3.5, 8.5 | 2.95$\times {10}^{5}$ | 11.2 | 0.10 | 1.67 | 2878 | |

9 | 5.0, 10.5 | 2.79$\times {10}^{5}$ | 11.5 | 0.32 | 1.99 | 2902 |

**Table 13.**Turbine system response for selected design load cases. DLC, design load case; NTM, normal turbulence model; ETM, extreme turbulence model; ECD, extreme coherent gust with direction change; EWS, extreme wind shear; EOG, extreme operating gust; EDC, extreme direction change.

Design Situation | DLC | Wind Condition | PtfmSurge | PtfmPitch | RootMyc1 | TwrBsMyt | TFair |
---|---|---|---|---|---|---|---|

Power production | 1.1 | NTM | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |

1.3 | ETM | 1.03 | 1.10 | 1.11 | 1.01 | 1.04 | |

1.4 | ECD | 0.80 | 0.83 | 1.13 | 0.81 | 0.84 | |

1.5 | EWS | 0.81 | 0.82 | 0.90 | 0.85 | 0.83 | |

Startup | 3.2 | EOG | 1.13 | 1.15 | 1.15 | 1.22 | 1.18 |

3.3 | EDC | 1.07 | 1.14 | 1.11 | 1.17 | 1.10 |

**Table 14.**Statistics (Maxima) of the integrated SNL 13.2-MW semi-submersible floating offshore wind turbine system.

${\mathit{V}}_{\mathit{wind}}$ (m/s) | PtfmSurge (m) | PtfmPitch (deg) | RootMyc1 (MN-m) | TwrBsMyt (MN-m) | TAnch (KN) |
---|---|---|---|---|---|

4 | 11.5 | 1.9 | 27.0 | 335.9 | 532.70 |

8 | 23.0 | 3.6 | 59.2 | 529.3 | 2719.00 |

11.3 | 23.6 | 4.8 | 64.1 | 628.7 | 2817.00 |

16 | 20.1 | 5.0 | 64.6 | 607.0 | 2029.00 |

20 | 16.9 | 4.3 | 56.3 | 605.3 | 1376.00 |

24 | 13.9 | 3.9 | 57.6 | 547.5 | 944.50 |

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Liu, J.; Thomas, E.; Manuel, L.; Griffith, D.T.; Ruehl, K.M.; Barone, M.
Integrated System Design for a Large Wind Turbine Supported on a Moored Semi-Submersible Platform. *J. Mar. Sci. Eng.* **2018**, *6*, 9.
https://doi.org/10.3390/jmse6010009

**AMA Style**

Liu J, Thomas E, Manuel L, Griffith DT, Ruehl KM, Barone M.
Integrated System Design for a Large Wind Turbine Supported on a Moored Semi-Submersible Platform. *Journal of Marine Science and Engineering*. 2018; 6(1):9.
https://doi.org/10.3390/jmse6010009

**Chicago/Turabian Style**

Liu, Jinsong, Edwin Thomas, Lance Manuel, D. Todd Griffith, Kelley M. Ruehl, and Matthew Barone.
2018. "Integrated System Design for a Large Wind Turbine Supported on a Moored Semi-Submersible Platform" *Journal of Marine Science and Engineering* 6, no. 1: 9.
https://doi.org/10.3390/jmse6010009