Multi-Fidelity Aerodynamic Modeling of a Floating Offshore Wind Turbine Rotor

2020 ◽  
Author(s):  
Kai Zhang ◽  
Onur Bilgen
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Modeling Method ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Element Theory ◽  
Wind Turbine Rotor ◽  
Blade Element

Abstract This paper presents a comparison of low- and mid-fidelity aerodynamic modelling of floating offshore wind turbine rotors. The low-fidelity approach employs the conventional Blade Element Momentum theory implemented in AeroDyn of OpenFAST. This model ignores the aerodynamic interactions between different blade elements, and the forces on the blade are determined from the balance between momentum theory and blade element theory. With this method, it is possible to calculate the aerodynamic performance for different settings with low computational cost. For the mid-fidelity approach, the Actuator Line Modeling method implemented in turbinesFoam (an OpenFOAM library) is used. This method is built upon a combination of the blade element theory for modeling the blades, and a Navier-Stokes description of the wake flow field. Thus, it can capture the wake dynamics without resolving the detailed flows near the blades. The aerodynamic performance of the DTU 10 MW reference wind turbine rotor is studied using the two methods. The effects of wind speed, tip speed ratio, and blade pitch angles are assessed. Good agreement is observed between the two methods at low tip speed ratios, while the Actuator Line Modeling method predicts slightly higher power coefficients at high tip speed ratios. In addition, the ability of the Actuator Line Modeling Method to capture the wake dynamics of the rotor in an unsteady inflow is demonstrated. In the future, the multi-fidelity aerodynamic modules developed in this paper will be integrated with the hydro-kinematics and hydro-dynamics of a floating platform and a mooring system, to achieve a fully coupled framework for the analysis and design optimization of floating offshore wind turbines.

Modelling the Aerodynamics of a Floating Wind Turbine Model Using a CFD-Based Actuator Disc Method

2019 ◽  
Author(s):  
Ryan Bezzina ◽  
Tonio Sant ◽  
Daniel Micallef
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Speed Ratio ◽  
Offshore Wind Turbine ◽  
Floating Platform ◽  
Blade Element Theory ◽  
Floating Wind Turbine ◽  
Actuator Disc ◽  
Turbine Wake ◽  
Blade Element

Abstract Significant research in the field of Floating Offshore Wind Turbine (FOWT) rotor aerodynamics has been documented in literature, including validated aerodynamic models based on Blade Element Momentum (BEM) and vortex methods, amongst others. However, the effects of platform induced motions on the turbine wake development downstream of the rotor plane or any research related to such areas is rather limited. The aims of this paper are two-fold. Initially, results from a CFD-based Actuator Disc (AD) code for a fixed (non-surging) rotor are compared with those obtained from a Blade Element Momentum (BEM) theory, as well as previously conducted experimental work. Furthermore, the paper also emphasises the effect of tip speed ratio (TSR) on the rotor efficiency. This is followed by the analysis of floating wind turbines specifically in relation to surge displacement, through an AD technique implemented in CFD software, ANSYS Fluent®. The approach couples the Blade Element Theory (BET) for estimating rotating blade loads with a Navier Stokes solver to simulate the turbine wake. With regards to the floating wind turbine cases, the code was slightly altered such that BET was done in a transient manner i.e. following sinusoidal behaviour of waves. The AD simulations were performed for several conditions of TSRs and surge frequencies, at a constant amplitude. Similar to the fixed rotor analysis, significant parameters including thrust and power coefficients, amongst others, were studied against time and surge position. The floating platform data extracted from the AD approach was compared to the non-surging turbine data obtained, to display platform motion effects clearly. Data from hot wire near wake measurements and other simulation methods were also consulted.

ALE–VMS formulation for stratified turbulent incompressible flows with applications

2015 ◽  
Vol 25 (12) ◽  
pp. 2349-2375 ◽  
Author(s):  
Y. Bazilevs ◽  
A. Korobenko ◽  
J. Yan ◽  
A. Pal ◽  
S. M. I. Gohari ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Incompressible Flows ◽  
Stable Stratification ◽  
Turbine Rotor ◽  
Multiscale Methods ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Moving Domains ◽  
Thrust And Torque ◽  
Wind Turbine Rotor

A numerical formulation for incompressible flows with stable stratification is developed using the framework of variational multiscale methods. In the proposed formulation, both density and temperature stratification are handled in a unified manner. The formulation is augmented with weakly-enforced essential boundary conditions and is suitable for applications involving moving domains, such as fluid–structure interaction. The methodology is tested using three numerical examples ranging from flow-physics benchmarks to a simulation of a full-scale offshore wind-turbine rotor spinning inside an atmospheric boundary layer. Good agreement is achieved with experimental and computational results reported by other researchers. The wind-turbine rotor simulation shows that flow stratification has a strong influence on the dynamic rotor thrust and torque loads.

scholarly journals Dynamic Response of a Conceptual Designed Articulated Offshore Wind Turbine

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Pei Zhang ◽  
Yan Li ◽  
Jiayang Gu ◽  
Tianchang Yin ◽  
Zhiqiang Hu ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Three Dimensional ◽  
Wind Pressure ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Aerodynamic Load ◽  
Offshore Area ◽  
Momentum Theory ◽  
Blade Element

Abstract Focusing on the 75 m depth offshore area, an articulated foundation is proposed for supporting National Renewable Energy Laboratory (NREL) 5 MW offshore wind turbine (OWT). Through the overall sensitivity check on hydrostatic performance, the main parameters are set to meet the requirements of stability and economy. An in-house code was programmed to simulate the dynamic response of the articulated offshore wind turbine (AOWT). The aerodynamic load on rotating blades and the wind pressure load on tower are calculated based on the blade element momentum theory and the empirical formula, respectively. The hydrodynamic load is simulated by the three-dimensional potential flow theory. The motions of foundation, the aerodynamic performance of the wind turbine, and the loads on the articulated joint are documented in different cases. According to the simulations, the articulated offshore wind turbine shows feasibility to work in the particular area.

Loads Calculation of Pitch Bearing of Wind Turbine

2010 ◽  
Vol 148-149 ◽  
pp. 479-484
Author(s):  
Yun Feng Li
Keyword(s):  
Coordinate System ◽  
Wind Turbine ◽  
Aerodynamic Loads ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Bearing Load ◽  
Calculation Process ◽  
Pitch Bearing ◽  
Element Theory ◽  
Blade Element

Loads calculation process for pitch bearing of wind turbine was presented. The aerodynamic of the rotor was analyzed by using momentum theory and blade element theory firstly; then the aerodynamic loads, the gravitational loads and the centrifugal loads of the pitch bearing were calculated along each axis of the bearing coordinate system; thirdly, all the loads of each direction of the pitch bearing load were composed into three loads, they are radial, axial and tilting moment loads. A calculation example was given at last.

Aerodynamic Modeling Research of Wind Turbine Suitable for Individual Pitch Control

2013 ◽  
Vol 823 ◽  
pp. 175-179
Author(s):  
Feng Gao
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Theory Model ◽  
Pitch Control ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Control Research ◽  
Individual Pitch Control ◽  
Element Theory ◽  
Blade Element

Momentum theory model which was widely used in pitch control cant calculate wind turbine load, so it can't meet pitch control research needs of large-scale wind turbine. In this paper, the traditional model based on momentum theory firstly was improved to be able to calculate load under some hypothesis. Then the wind turbine model suitable for individual pitch control was built based on blade element theory. And wind shear and tower shadow on load of wind turbine was calculated and analyzed. Finally, the model was simulated in the turbulent flow conditions and load was analyzed by Bladed. Simulations indicate that the model built in the paper can be used in simulation and verification of individual pitch control, and the conclusions drawn by load analysis can provide theoretic basis and the reference standard for individual pitch control strategy.

Sign in / Sign up

Export Citation Format

Share Document