scholarly journals Multipoint high-fidelity CFD-based aerodynamic shape optimization of a 10 MW wind turbine

2018 ◽  
Author(s):  
Mads H. Aa. Madsen ◽  
Frederik Zahle ◽  
Niels N. Sørensen ◽  
Joaquim R. R. A. Martins
Keyword(s):  
Shape Optimization ◽  
Wind Turbine ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
High Fidelity ◽  
Cross Sectional ◽  
Extreme Loads ◽  
Sectional Shape

Abstract. The wind energy industry relies heavily on CFD to analyze new turbine designs. To utilize CFD further upstream the design process where lower fidelity methods such as BEM are more common, requires the development of new tools. Tools that utilize numerical optimization are particularly valuable because they reduce the reliance on design by trial and error. We present the first comprehensive 3D CFD adjoint-based shape optimization of a modern 10&thisp;MW offshore wind turbine. The optimization problem is aligned with a case study from IEA Wind Task 37, making it possible to compare our findings with the BEM results from this case study, allowing us to determine the value of design optimization based on high-fidelity models. The comparison shows, that the overall design trends suggested by the two models do agree, and that it is particularly valuable to consult the high-fidelity model in areas such as root and tip where BEM is inaccurate. In addition, we compare two different CFD solvers to quantify the effect of modeling compressibility and to estimate the accuracy of the chosen grid resolution and order of convergence of the solver. Meshes up to 14 · 106 cells are used in the optimization whereby flow details are resolved. The present work shows that it is now possible to successfully optimize modern wind turbines aerodynamically under normal operating conditions using RANS models. The key benefit of a 3D RANS approach is that it is possible to optimize the blade planform and cross-sectional shape simultaneously, thus tailoring the shape to the actual 3D flow over the rotor, which is particularly important near the root and tip of the blade. This work does not address evaluation of extreme loads used for structural sizing, where BEM-based methods have proven very accurate, and therefore will likely remain the method of choice.

scholarly journals Multipoint high-fidelity CFD-based aerodynamic shape optimization of a 10 MW wind turbine

2019 ◽  
Vol 4 (2) ◽  
pp. 163-192 ◽  
Author(s):  
Mads H. Aa. Madsen ◽  
Frederik Zahle ◽  
Niels N. Sørensen ◽  
Joaquim R. R. A. Martins
Keyword(s):  
Shape Optimization ◽  
Wind Turbine ◽  
International Energy Agency ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
High Fidelity ◽  
Energy Agency ◽  
Cross Sectional

Abstract. The wind energy industry relies heavily on computational fluid dynamics (CFD) to analyze new turbine designs. To utilize CFD earlier in the design process, where lower-fidelity methods such as blade element momentum (BEM) are more common, requires the development of new tools. Tools that utilize numerical optimization are particularly valuable because they reduce the reliance on design by trial and error. We present the first comprehensive 3-D CFD adjoint-based shape optimization of a modern 10 MW offshore wind turbine. The optimization problem is aligned with a case study from International Energy Agency (IEA) Wind Task 37, making it possible to compare our findings with the BEM results from this case study and therefore allowing us to determine the value of design optimization based on high-fidelity models. The comparison shows that the overall design trends suggested by the two models do agree, and that it is particularly valuable to consult the high-fidelity model in areas such as root and tip where BEM is inaccurate. In addition, we compare two different CFD solvers to quantify the effect of modeling compressibility and to estimate the accuracy of the chosen grid resolution and order of convergence of the solver. Meshes up to 14×106 cells are used in the optimization whereby flow details are resolved. The present work shows that it is now possible to successfully optimize modern wind turbines aerodynamically under normal operating conditions using Reynolds-averaged Navier–Stokes (RANS) models. The key benefit of a 3-D RANS approach is that it is possible to optimize the blade planform and cross-sectional shape simultaneously, thus tailoring the shape to the actual 3-D flow over the rotor. This work does not address evaluation of extreme loads used for structural sizing, where BEM-based methods have proven very accurate, and therefore will likely remain the method of choice.

Impact of Simulation Duration for Offshore Floating Wind Turbine Analysis Using a Coupled FAST-OrcaFlex Model

2019 ◽  
Author(s):  
Ajit C. Pillai ◽  
Philipp R. Thies ◽  
Lars Johanning
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Offshore Wind Turbine ◽  
Wind Speeds ◽  
Extreme Loads ◽  
Offshore Floating Wind Turbine ◽  
The Impact ◽  
Selection Of

Abstract This paper uses a coupled FAST-OrcaFlex model in order to explore the impact of simulation duration on model convergence. The work analyses both operational and extreme cases, assessing the estimated fatigue and extreme loads experienced by a floating offshore wind turbine and its mooring system. Considering an OC4 semi-submersible deployed with the NREL 5 MW turbine, the case study performs a parametric sweep over a range of wind speeds, sea states, and simulation durations. Through this sweep, the paper establishes the impact of the simulation duration for this particular floating offshore wind turbine and characterizes the convergence properties of the loads and excursions as a function of the simulation duration. The results inform the selection of simulation durations to be used in coupled aero-hydro models and optimization frameworks for floating offshore wind applications and can be used to aid the development of guidance and standards for coupled floating offshore wind turbine models.

scholarly journals Impact of Typhoons on Floating Offshore Wind Turbines: A Case Study of Typhoon Mangkhut

2021 ◽  
Vol 9 (5) ◽  
pp. 543
Author(s):  
Jiawen Li ◽  
Jingyu Bian ◽  
Yuxiang Ma ◽  
Yichen Jiang
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Safety Evaluation ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Motion Response ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Coupling Motion

A typhoon is a restrictive factor in the development of floating wind power in China. However, the influences of multistage typhoon wind and waves on offshore wind turbines have not yet been studied. Based on Typhoon Mangkhut, in this study, the characteristics of the motion response and structural loads of an offshore wind turbine are investigated during the travel process. For this purpose, a framework is established and verified for investigating the typhoon-induced effects of offshore wind turbines, including a multistage typhoon wave field and a coupled dynamic model of offshore wind turbines. On this basis, the motion response and structural loads of different stages are calculated and analyzed systematically. The results show that the maximum response does not exactly correspond to the maximum wave or wind stage. Considering only the maximum wave height or wind speed may underestimate the motion response during the traveling process of the typhoon, which has problems in guiding the anti-typhoon design of offshore wind turbines. In addition, the coupling motion between the floating foundation and turbine should be considered in the safety evaluation of the floating offshore wind turbine under typhoon conditions.

Global Responses and Loads Analysis of a 750-kW Semi-Submersible Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2019 ◽  
Author(s):  
Thanh Dam Pham ◽  
Junbae Kim ◽  
Byoungcheon Seo ◽  
Rupesh Kumar ◽  
Youngjae Yu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Environmental Conditions ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
East Sea ◽  
Offshore Wind Turbine ◽  
Test Model ◽  
Scaled Model ◽  
Floating Offshore Wind Turbine ◽  
Extreme Loads

Abstract A pilot floating offshore wind turbine project of Korea was proposed for installing in the East Sea of Korea. The prototype is a semisubmersible platform supporting a 750-kW wind turbine. A scaled model was tested in the basin tank of the University of Ulsan at scale ratio 1:40. The 750-kW floating offshore wind turbine was modeled by using the NREL-FAST code. Numerical results were validated by comparing with those of the test model. This paper analyzes dynamic responses and loads of the wind turbine system under extreme environmental conditions. Extreme environmental conditions based on metocean data of East Sea Korea. Extreme responses and extreme loads are important data for designing the structure of the 750 kW semi-submersible floating offshore wind turbine.

scholarly journals Intelligent Fault Diagnosis Techniques Applied to an Offshore Wind Turbine System

2019 ◽  
Vol 9 (4) ◽  
pp. 783 ◽  
Author(s):  
Silvio Simani ◽  
Paolo Castaldi
Keyword(s):  
Fault Diagnosis ◽  
Wind Turbine ◽  
Operating Conditions ◽  
Fault Detection And Isolation ◽  
Offshore Wind ◽  
Data Driven ◽  
Offshore Wind Turbine ◽  
Wind Turbine System ◽  
High Degree ◽  
Offshore Plants

Fault diagnosis of wind turbine systems is a challenging process, especially for offshore plants, and the search for solutions motivates the research discussed in this paper. In fact, these systems must have a high degree of reliability and availability to remain functional in specified operating conditions without needing expensive maintenance works. Especially for offshore plants, a clear conflict exists between ensuring a high degree of availability and reducing costly maintenance. Therefore, this paper presents viable fault detection and isolation techniques applied to a wind turbine system. The design of the so-called fault indicator relies on an estimate of the fault using data-driven methods and effective tools for managing partial knowledge of system dynamics, as well as noise and disturbance effects. In particular, the suggested data-driven strategies exploit fuzzy systems and neural networks that are used to determine nonlinear links between measurements and faults. The selected architectures are based on nonlinear autoregressive with exogenous input prototypes, which approximate dynamic relations with arbitrary accuracy. The designed fault diagnosis schemes were verified and validated using a high-fidelity simulator that describes the normal and faulty behavior of a realistic offshore wind turbine plant. Finally, by accounting for the uncertainty and disturbance in the wind turbine simulator, a hardware-in-the-loop test rig was used to assess the proposed methods for robustness and reliability. These aspects are fundamental when the developed fault diagnosis methods are applied to real offshore wind turbines.

Foundation structural health monitoring of an offshore wind turbine—a full-scale case study

2016 ◽  
Vol 15 (4) ◽  
pp. 389-402 ◽  
Author(s):  
Wout Weijtjens ◽  
Tim Verbelen ◽  
Gert De Sitter ◽  
Christof Devriendt
Keyword(s):  
Structural Health Monitoring ◽  
Wind Turbine ◽  
Health Monitoring ◽  
Full Scale ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Structural Health

Aeromechanical Analysis of Two-Bladed Downwind Turbine Using a Nacelle Tilt Control

2017 ◽  
Author(s):  
Qiuying Zhao ◽  
Chunhua Sheng ◽  
Yousuf Al-Khalifin ◽  
Abdollah Afjeh
Keyword(s):  
Wind Turbine ◽  
Structural Dynamics ◽  
Control Method ◽  
Offshore Wind ◽  
Structural Deformation ◽  
Offshore Wind Turbine ◽  
System Response ◽  
High Fidelity ◽  
Dynamics Analysis ◽  
Control Concept

The structural dynamics and response of a two-bladed downwind wind turbine using a new nacelle tilt control are numerically investigated based on a coupled Computational Fluid Dynamics and Computational Structural Dynamics analysis. The new wind turbine tilt control method is investigated to regulate the power output under a varying wind speed environment for offshore wind turbines. The high fidelity aerodynamic loads obtained from CFD computations are used as input in a CSD code to perform a structural dynamics analysis in order to predict the system response and structural deformation of the two-bladed downwind turbine. The coupled CFD and CSD analysis provide high fidelity assessments of the aeromechanical performance with increased accuracy to evaluate the new nacelle tilt control concept, which may lead to an alternative wind turbine control strategy with reduced costs for offshore wind turbine operations.

scholarly journals Validation of Numerical Models of the Offshore Wind Turbine From the Alpha Ventus Wind Farm Against Full-Scale Measurements Within OC5 Phase III

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Wojciech Popko ◽  
Amy Robertson ◽  
Jason Jonkman ◽  
Fabian Wendt ◽  
Philipp Thomas ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Wind Farm ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Phase Iii ◽  
Offshore Wind Turbine ◽  
Discrete Fourier Transforms ◽  
Simulation Tools ◽  
Axial Forces

Abstract The main objective of the Offshore Code Comparison Collaboration Continuation, with Correlation (OC5) project is validation of aero-hydro-servo-elastic simulation tools for offshore wind turbines (OWTs) through comparison of simulated results to the response data of physical systems. Phase III of the OC5 project validates OWT models against the measurements recorded on a Senvion 5M wind turbine supported by the OWEC Quattropod from the alpha ventus offshore wind farm. The following operating conditions of the wind turbine were chosen for the validation: (1) idling below the cut-in wind speed, (2) rotor-nacelle assembly (RNA) rotation maneuver below the cut-in wind speed, (3) power production below and above the rated wind speed, and (4) shutdown. A number of validation load cases were defined based on these operating conditions. The following measurements were used for validation: (1) strains and accelerations recorded on the support structure and (2) pitch, yaw, and azimuth angles, generator speed, and electrical power recorded from the RNA. Strains were not directly available from the majority of the OWT simulation tools; therefore, strains were calculated based on out-of-plane bending moments, axial forces, and cross-sectional properties of the structural members. The simulation results and measurements were compared in terms of time series, discrete Fourier transforms, power spectral densities, and probability density functions of strains and accelerometers. A good match was achieved between the measurements and models setup by OC5 Phase III participants.

Developing Inspection Methodologies for Offshore Wind Turbine Facilities

2009 ◽  
Author(s):  
Robert E. Sheppard ◽  
Frank J. Puskar
Keyword(s):  
Wind Turbine ◽  
Oil And Gas ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Guidance Document ◽  
Management Service ◽  
The Us ◽  
Need To Evaluate ◽  
Integrity Management

With the expected introduction of wind turbine facilities for the generation of electricity to the US Offshore Continental Shelf (OCS) waters, there is a need to evaluate how the long term operations of these facilities can be ensured through Integrity Management (IM) activities, particularly inspections. There is a long operational history of IM in the Gulf of Mexico, offshore California and Alaska, and around the world for fixed and floating oil and gas platforms for drilling and production. Both prescriptive and Risk-Based Inspection (RBI) methodologies have been established and implemented to direct inspection operations for these facilities. This experience provides a foundation for implementing similar Integrity Management programs for offshore wind turbine structures. Through the incorporation of existing guidance for subsea structures, above-water structures and access systems along with guidance from subject matter experts regarding critical inspection areas, inspection techniques, and inspection intervals, a guidance document has been developed which includes regional variations that address unique operating conditions in US waters. This work was funded by the US Department of the Interior, Minerals Management Service (MMS).

Sign in / Sign up

Export Citation Format

Share Document