Influence of Model Simplifications Excitation Force in Surge for a Floating Foundation for Offshore Wind Turbines

Development of novel offshore wind turbine designs and technologies are necessary to reduce the cost of offshore wind energy since offshore wind turbines need to withstand ice and waves in addition to wind, a markedly different environment from their onshore counterparts. This paper focuses on major design challenges of offshore wind turbines and offers an advanced concept wind turbine that can significantly reduce the cost of offshore wind energy as an alternative to the current popular designs. The design consists of a two-blade, downwind rotor configuration fitted to a fixed bottom or floating foundation. Preliminary results indicate that cost savings of nearly 25% are possible compared with the conventional upwind wind turbine designs.

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Motion response analysis of floating foundation of offshore wind turbines

Journal of Physics Conference Series ◽

10.1088/1742-6596/1168/2/022008 ◽

2019 ◽

Vol 1168 ◽

pp. 022008

Author(s):

Kong-de He ◽

Zhi-chao Chen ◽

Xu-guang Xie ◽

Zi-fan Fang ◽

Xue-hui He

Keyword(s):

Wind Turbines ◽

Offshore Wind ◽

Response Analysis ◽

Motion Response ◽

Offshore Wind Turbines ◽

Floating Foundation

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WindFloat: A Floating Foundation for Offshore Wind Turbines—Part I: Design Basis and Qualification Process

Volume 4: Ocean Engineering; Ocean Renewable Energy; Ocean Space Utilization, Parts A and B ◽

10.1115/omae2009-79229 ◽

2009 ◽

Cited By ~ 22

Author(s):

Dominique Roddier ◽

Christian Cermelli ◽

Alla Weinstein

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Oil And Gas ◽

Large Diameter ◽

Offshore Wind ◽

Site Location ◽

Offshore Wind Turbines ◽

Design Basis ◽

Floating Foundation ◽

Visual Impacts

This paper and the corresponding hydrodynamic and structural study paper (also in these proceedings) summarize the feasibility study conducted for the WindFloat technology. The WindFloat is a 3-legged floating foundation for very large offshore wind turbines. It is designed to accommodate a wind turbine, 5 MW or larger, on one of the columns of the hull with minimal modifications to the tower, nacelle and turbine. Technologies for floating foundations for offshore wind turbines are evolving. It is agreed by most experts that the offshore wind industry will see a significant increase in activity in the near future. Fixed offshore turbines are limited in water depth to approximately 30∼50m. Market transition to deeper waters is inevitable, provided suitable technologies can be developed. Despite the increase in complexity, a floating foundation offers distinct advantages: • Flexibility in site location. • Access to superior wind resources further offshore. • Ability to locate in coastal regions with limited shallow continental shelf. • Ability to locate further offshore to eliminate visual impacts. • An integrated structure, without a need to redesign the mast foundation connection for every project. • Simplified offshore installation procedures. Anchors are significantly cheaper to install than fixed foundations and large diameter towers. This paper focuses on the design basis for wind turbine floating foundations, and explores the requirements that must be addressed by design teams in this new field. It shows that the design of the hull for a large wind turbine must draw on the synergies with oil and gas offshore platform technology, while accounting for the different design requirements and functionality of the wind turbine.

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Research Development and Key Technical on Floating Foundation for Offshore Wind Turbines

Advanced Materials Research ◽

10.4028/scientific5/amr.446-449.1014 ◽

2012 ◽

Vol 446-449 ◽

pp. 1014-1019 ◽

Cited By ~ 1

Author(s):

Ruo Yu Zhang ◽

Chao He Chen ◽

You Gang Tang ◽

Xiao Yan Huang

Keyword(s):

Wind Turbines ◽

Offshore Wind ◽

Research Development ◽

Offshore Wind Turbines ◽

Floating Foundation

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Structural design of a floating foundation for offshore wind turbines in red sea

Analysis and Design of Marine Structures ◽

10.1201/b15120-78 ◽

2013 ◽

pp. 575-583 ◽

Cited By ~ 1

Author(s):

K Hussein ◽

A Hussein ◽

E Hegazy ◽

A Amin

Keyword(s):

Red Sea ◽

Wind Turbines ◽

Structural Design ◽

Offshore Wind ◽

Offshore Wind Turbines ◽

Floating Foundation

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WindFloat: A floating foundation for offshore wind turbines

Journal of Renewable and Sustainable Energy ◽

10.1063/1.3435339 ◽

2010 ◽

Vol 2 (3) ◽

pp. 033104 ◽

Cited By ~ 193

Author(s):

Dominique Roddier ◽

Christian Cermelli ◽

Alexia Aubault ◽

Alla Weinstein

Keyword(s):

Wind Turbines ◽

Offshore Wind ◽

Offshore Wind Turbines ◽

Floating Foundation

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WindFloat: A Floating Foundation for Offshore Wind Turbines—Part II: Hydrodynamics Analysis

Volume 4: Ocean Engineering; Ocean Renewable Energy; Ocean Space Utilization, Parts A and B ◽

10.1115/omae2009-79231 ◽

2009 ◽

Cited By ~ 23

Author(s):

Christian Cermelli ◽

Dominique Roddier ◽

Alexia Aubault

Keyword(s):

Wind Turbine ◽

Wind Turbines ◽

Hydrodynamic Model ◽

Offshore Wind ◽

Scale Model ◽

Hydrodynamic Analysis ◽

Offshore Wind Turbines ◽

Floating Foundation ◽

Ongoing Work ◽

Aerodynamic Simulation

WindFloat is a floating foundation for very large offshore wind turbines. This paper describes the hydrodynamic analysis of the hull, as well as ongoing work consisting of coupling hull hydrodynamics with wind-turbine aerodynamic forces. Three main approaches are presented in this paper: - The numerical hydrodynamic model of the platform and its mooring system; - Wave tank testing of a scale model of the platform with simplified aerodynamic simulation of the wind turbine; - FAST, an aerodynamic software package for wind turbine analysis with the ability to be coupled to the hydrodynamic model. These conference proceedings include two other papers presenting the design basis and main systems of this floating foundation [1], as well as structural analysis of the hull and mast [2].

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WindFloat: A Floating Foundation for Offshore Wind Turbines—Part III: Structural Analysis

Volume 1: Offshore Technology ◽

10.1115/omae2009-79232 ◽

2009 ◽

Cited By ~ 8

Author(s):

Alexia Aubault ◽

Christian Cermelli ◽

Dominique Roddier

Keyword(s):

Wind Turbines ◽

Structural Engineering ◽

Structural Response ◽

Offshore Wind ◽

Design Teams ◽

Hydrodynamic Analysis ◽

Offshore Wind Turbines ◽

Floating Foundation ◽

Experimental Validations ◽

Offshore Wind Turbine Coupled Motion in Regular Waves

Marine Technology Society Journal ◽

10.4031/mtsj.54.2.2 ◽

2020 ◽

Vol 54 (2) ◽

pp. 5-16

Author(s):

Bao-Ji Zhang ◽

Gao Yu ◽

Wen-Xuan She

Keyword(s):

Wind Turbines ◽

Wave Force ◽

Offshore Wind ◽

Hydrodynamic Performance ◽

Offshore Wind Turbine ◽

Theoretical Principle ◽

Regular Waves ◽

Offshore Wind Turbines ◽

Floating Foundation ◽

Motion Responses

AbstractThis study aims to accurately predict the hydrodynamic performance and motion responses of offshore wind turbines on the basis of computational fluid dynamics (CFD) theory. Continuous and Navier-Stokes (N-S) equations are employed as control equations, and the k-ε model is used as a turbulence model. The finite difference method is utilized to discretize the equation. The Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm is applied to solve the control equation, and the volume-of-fluid (VOF) method is used to capture the free surface. The numerical wave tank of irregular wave is also established. The hydrodynamic performances and motion responses of the offshore wind turbines under regular waves are studied. First, we assume a floating foundation without the influence of a rotational fan and examine its motion responses and wave force in three typical sea conditions, namely, Levels 5, 6, and 7. Thereafter, we use a series of force and torque acting on the rotating center of the offshore to substitute for the influence of the rotational fan on the floating foundation. Then, we study the hydrodynamic performance influenced by blade rotation of the floating foundation in various sea conditions and three wind speeds, namely, 5, 8, and 11 m/s. Research results can provide usable theoretical principle and technical support for the investigation of the hydrodynamic performance and motion responses of similar offshore wind turbines.

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