Offshore Wind Turbine Dynamic Analysis

A special issue of Journal of Marine Science and Engineering (ISSN 2077-1312). This special issue belongs to the section "Coastal Engineering".

Deadline for manuscript submissions: closed (10 November 2021) | Viewed by 25642

Special Issue Editor

Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580, Japan
Interests: offshore hydrodynamics; wave–structure interaction; offshore floating wind; wave-induced loads; wind-induced loads; seakeeping; mooring analysis; wave energy arrays; numerical modeling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Offshore wind energy has rapidly progressed in the past decade. As many countries (UK, China, Japan, Norway, Canada, and countries in the European Union, etc.) have announced their target to achieve carbon neutrality around 2050~2060. The development of offshore wind technology is expected to embrace greater prosperity in the upcoming decades.

We look forward to receiving your contribution on state of the art and perspectives on the modelling, experiment and analysis of offshore wind turbines and all related topics, such as hydrodynamics, aerodynamics, control, moorings, structural analysis, turbine design, wind farm, and review articles, etc.

This Special Issue will publish papers on research frontiers with respect to the above subjects, to provide a rapid processing time regarding reviewing and publishing, to disseminate the articles freely for research, teaching, and reference purposes, as well as to achieve an increasing research impact.

Dr. Yingyi Liu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Journal of Marine Science and Engineering is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • floating offshore wind turbines
  • bottom-mounted offshore wind turbines
  • numerical modelling
  • experimental modelling
  • new wind turbine concept
  • hydrodynamic modelling/analysis
  • aerodynamic modelling/analysis
  • structural modelling/analysis
  • mooring modelling and design
  • control algorithm/strategy

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

17 pages, 6552 KiB  
Article
Numerical Investigation on Aerodynamic Characteristics of Dual-Rotor Wind Turbines
by Kai Wang, Tianhui Liu, Yuanchen Wan, Muk Chen Ong and Tiecheng Wu
J. Mar. Sci. Eng. 2022, 10(12), 1887; https://doi.org/10.3390/jmse10121887 - 4 Dec 2022
Cited by 3 | Viewed by 2618
Abstract
Improving power output and reducing costs are crucial to the sustainable development of offshore wind power. In the present study, a dual-rotor wind turbine (DRWT) is proposed to improve wind energy capture efficiency by adding an auxiliary rotor behind the main rotor. The [...] Read more.
Improving power output and reducing costs are crucial to the sustainable development of offshore wind power. In the present study, a dual-rotor wind turbine (DRWT) is proposed to improve wind energy capture efficiency by adding an auxiliary rotor behind the main rotor. The two rotors can be the same size or different sizes. This will result in different aerodynamic characteristics for DRWTs. In this paper, the NREL Offshore Baseline-5 MW and the NREL 750 kW single-rotor wind turbines (SRWTs) are used to configure three different types of DRWTs. The power output and wake characteristics of three different DRWTs with co-rotating (CO-DRWT) and counter-rotating (CR-DRWT) configurations on an actual scale are compared. The Reynolds-averaged Navier–Stokes (RANS) model with k-ω SST (shear stress transport model) is used to simulate the unsteady flow generated by the DRWT’s rotation. The present numerical results show that the power coefficient of the 5 MW-5 MW CO-DRWT can reach 1.22 times that of the 5 MW SRWT. Moreover, a faster wake velocity deficit recovery is found in the 5 MW-5 MW DRWTs because the high-velocity flow caused by the merging and mixing of the trailing vortices of the 5 MW-5 MW DRWTs brings an energy supplement to the wake velocity deficit. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

20 pages, 6311 KiB  
Article
Variable-Gain Higher-Order Sliding Mode Pitch Control of Floating Offshore Wind Turbine
by Shuzhen Li, Yaozhen Han, Weigang Pan, Shuang Liu and Mingdong Hou
J. Mar. Sci. Eng. 2021, 9(11), 1172; https://doi.org/10.3390/jmse9111172 - 25 Oct 2021
Cited by 9 | Viewed by 1993
Abstract
A variable-gain higher-order sliding mode pitch control strategy is proposed for a strongly nonlinear and coupled floating offshore wind power system. The main goal of the proposed strategy is to suppress platform motion caused by random disturbances such as waves and wind speed [...] Read more.
A variable-gain higher-order sliding mode pitch control strategy is proposed for a strongly nonlinear and coupled floating offshore wind power system. The main goal of the proposed strategy is to suppress platform motion caused by random disturbances such as waves and wind speed and to reduce fatigue loads and power fluctuations. Feedback control and super-twisting second-order sliding mode algorithm were adopted to carry out collective pitch control and track the rated rotor speed, which involves the factor of platform pitch. To adaptively adjust the collective pitch control parameters according to random wave and wind speed disturbances, the barrier function method was used to conceive adaptive sliding mode control gains. For comparison purposes, the proposed control strategy and PI control were executed under different wind and wave conditions on a FAST and MATLAB/Simulink platform. Furthermore, the fatigue load was calculated by Mlife. The results demonstrate that the proposed scheme is effective and robust. Moreover, it has advantages in resisting external disturbances, especially in suppressing the platform pitch and roll, as well as reducing the power fluctuations and the fatigue load on the blade root. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

17 pages, 5665 KiB  
Article
Dynamic Responses for WindFloat Floating Offshore Wind Turbine at Intermediate Water Depth Based on Local Conditions in China
by Shan Gao, Lixian Zhang, Wei Shi, Bin Wang and Xin Li
J. Mar. Sci. Eng. 2021, 9(10), 1093; https://doi.org/10.3390/jmse9101093 - 7 Oct 2021
Cited by 4 | Viewed by 2554
Abstract
Offshore wind energy, a clean energy resource, is considered to be a possible alternative to fossil energy. Floating offshore wind technology is considered to be a proper concept to develop abundant wind energy in deep water. Considering the reality of offshore wind energy [...] Read more.
Offshore wind energy, a clean energy resource, is considered to be a possible alternative to fossil energy. Floating offshore wind technology is considered to be a proper concept to develop abundant wind energy in deep water. Considering the reality of offshore wind energy development in China, the floating offshore wind turbine concept is expected to be developed at moderate water depths. In this paper, a mooring system of the WindFloat semisubmersible floating offshore wind turbine (SFOWT) at a water depth of 60 m is designed. The dynamic responses of the WindFloat SFOWT under different wind–wave combination conditions are investigated using the coupled method and the simplified method, which do not include the effect of the tower top motion in the aerodynamic calculation. The results show that the dynamic responses of the WindFloat SFOWT, including the platform motions, tower loads, and mooring line tensions, perform fairly well at a moderate water depth. A comparison between the coupled method and simplified method shows that the calculated results are slightly different between the different conditions for the time domain results, response spectra results, and fatigue results. In addition, mooring line 1 (ML 1) suffers higher fatigue damage than ML2, which should be paid more attention. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

21 pages, 1293 KiB  
Article
Numerical Simulations of the Monotonic and Cyclic Behaviour of Offshore Wind Turbine Monopile Foundations in Clayey Soils
by Mian Xie and Susana Lopez-Querol
J. Mar. Sci. Eng. 2021, 9(9), 1036; https://doi.org/10.3390/jmse9091036 - 20 Sep 2021
Cited by 5 | Viewed by 6894
Abstract
Most of the reported centrifuge tests available in the existing literature on offshore wind turbine foundations are focused on the behaviour of monopiles in sands, but very few studies on clayey soils can be found, due to the very long saturation and consolidation [...] Read more.
Most of the reported centrifuge tests available in the existing literature on offshore wind turbine foundations are focused on the behaviour of monopiles in sands, but very few studies on clayey soils can be found, due to the very long saturation and consolidation periods required to properly conduct experiments in such materials. Moreover, most of the reported numerical simulations using finite element analyses have been validated with monotonic centrifuge tests only. In this research, both monotonic and cyclic performance of offshore wind turbines in clay are validated and justified. The relationship between the monopile rotation in clays and the geometry and strength of the soil has been found and quantified. A prediction of the rotation for a high number of cycles of loading, based on the one experienced by the pile during the first cycle, can be obtained using the correlation derived in the paper. For those cases in which the rotation does not reach a steady value after a high number of cycles, the cumulative rate has been found significantly larger than the prediction conducted with standard analytical methods. A new design methodology for the design of offshore monopile foundations in clay is presented. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

18 pages, 4148 KiB  
Article
Mean Wave Drift Forces on a Barge-Type Floating Wind Turbine Platform with Moonpools
by Lei Tan, Tomoki Ikoma, Yasuhiro Aida and Koichi Masuda
J. Mar. Sci. Eng. 2021, 9(7), 709; https://doi.org/10.3390/jmse9070709 - 27 Jun 2021
Cited by 9 | Viewed by 4013
Abstract
Barge-type platforms with moonpools are a promising type of foundation for floating offshore wind turbines due to their good seakeeping performance. In this paper, the mean wave drift force on a barge-type vertical-axis floating wind turbine with multiple moonpools was investigated through physical [...] Read more.
Barge-type platforms with moonpools are a promising type of foundation for floating offshore wind turbines due to their good seakeeping performance. In this paper, the mean wave drift force on a barge-type vertical-axis floating wind turbine with multiple moonpools was investigated through physical model testing and numerical calculations using WAMIT. The focus was on the characteristics of mean drift load and its optimization potential. The present numerical results indicated that the application of moonpools was useful in reducing horizontal mean drift force at specific frequencies, and the reason was ascribed to the significant radiation effect of the resonant water oscillations in moonpools. The observed reduction effect on mean drift force was shown to be dependent on the viscous damping of moonpool resonance. The experimental results showed that the maximum response of the mean sway drift force was reduced by the gyroscopic effect of rotations of the vertical-axis wind turbine, and this reduction effect became stronger as the rotating speed of the wind turbine increased, but was weakened as wave amplitude increased. The comparisons between experimental data and potential flow predictions indicated that viscous effects should be taken into account to reasonably estimate the mean wave drift forces on barge-type floating wind turbines. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

24 pages, 7684 KiB  
Article
Influence of Combined Motion of Pitch and Surge with Phase Difference on Aerodynamic Performance of Floating Offshore Wind Turbine
by Xiangheng Feng, Yonggang Lin, Guohao Zhang, Danyang Li, Hongwei Liu and Bin Wang
J. Mar. Sci. Eng. 2021, 9(7), 699; https://doi.org/10.3390/jmse9070699 - 25 Jun 2021
Cited by 9 | Viewed by 2134
Abstract
Platform motions induced by waves pose a challenge to accurately predict the aerodynamic performance of floating offshore wind turbines (FOWTs). In view of this, the power performance and wake structure of FOWTs under platform pitch, surge, and their combined motions were investigated in [...] Read more.
Platform motions induced by waves pose a challenge to accurately predict the aerodynamic performance of floating offshore wind turbines (FOWTs). In view of this, the power performance and wake structure of FOWTs under platform pitch, surge, and their combined motions were investigated in this paper, using the computational fluid dynamics software, STAR-CCM+, with overset meshing and rigid body motion techniques. First, the simulation cases in single and same-phase combined motions with different amplitudes and frequencies were performed. Afterward, the approach of calculating the phase difference between pitch and surge motions was proposed to investigate the influence of the combined motion with phase difference on the aerodynamic performance. Results show that the increment of amplitude and frequency augments the mean power output and aggravates the power fluctuation in single and same-phase combined motions. The intensity of power variation under combined motion with a phase difference is weakened at 0.1 Hz compared to the single motion, while enhanced at 0.2 Hz, showing a different influence law on the aerodynamic performance. In addition, this paper established the power fluctuation table based on real sea states of Shidao in China, providing a certain reference for the controller design in this sea area. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

22 pages, 8093 KiB  
Article
Towing Performance of the Submerged Floating Offshore Wind Turbine under Different Wave Conditions
by Conghuan Le, Jianyu Ren, Kai Wang, Puyang Zhang and Hongyan Ding
J. Mar. Sci. Eng. 2021, 9(6), 633; https://doi.org/10.3390/jmse9060633 - 6 Jun 2021
Cited by 7 | Viewed by 3473
Abstract
One of the advantages of floating offshore wind turbines (FOWTs) is that they can be designed to be easily wet towed and installed to reduce the cost of offshore construction. In this paper, a fully coupled towing system numerical model is established for [...] Read more.
One of the advantages of floating offshore wind turbines (FOWTs) is that they can be designed to be easily wet towed and installed to reduce the cost of offshore construction. In this paper, a fully coupled towing system numerical model is established for a novel 10 MW FOWT concept, namely, a submerged floating offshore wind turbine (SFOWT) to investigate the towing performance. Firstly, the numerical simulation is validated by comparison with model experiment results. Then, a series of numerical simulations are conducted to predict and compare the towing performance for a three-column SFOWT (TC-SFOWT) and a four-column SFOWT (FC-SFOWT) under different wave conditions. The results show that the two forms of SFOWT have good towing performance when the significant wave height is less than 5 m, which is the maximum wave height for the allowable towing condition. The FC-SFOWT shows relatively better performance in heave motion and roll motion, but the towing force is relatively larger compared with the TC-SFOWT under the same condition. When the significant wave height is 5 m, the maximum values of heave motion, pitch motion, and roll motion of the TC-SFOWT are 2.51 m, 2.14°, and 1.38°, respectively, while they are 2.25 m, 2.70°, and 1.21°, respectively, for the FC-SFOWT. Both the roll motion and the pitch motion are satisfied with the requirement that the roll and pitch are less than 5° during the towing process. The mean towing force of FC-SFOWT is 159.1 t at the significant wave height of 5 m, which is 52.8% larger than that of TC-SFOWT. The peak period mainly influences the frequency where the response peak appears in power spectra. The findings in this paper could provide some guidelines for wet towed operations. Full article
(This article belongs to the Special Issue Offshore Wind Turbine Dynamic Analysis)
Show Figures

Figure 1

Back to TopTop