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.

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.

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.

scholarly journals Horizontal Axis Wind Turbine Performance Analysis

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
N. Asmuin ◽  
◽  
Basuno B. ◽  
M.F. Yaakub ◽  
N.A. Nor Salim ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Thrust Coefficient ◽  
Blade Element Momentum Theory ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Turbine Performance ◽  
Blade Element

The present work uses the method of Blade Element Momentum Theory as suggested by Hansen. The method applied to three blade models adopted from Rahgozar S. with the airfoil data used the data provided by Wood D. The wind turbine performance described in term of the thrust coefficient C_T, torque coefficient C_Q and the power coefficient C_p . These three coefficient can be deduced from the Momentum theory or from the Blade element Theory(BET). The present work found the performance coefficient derived from the Momentum theory tent to over estimate. It is suggested to used the BET formulation in presenting these three coefficients. In overall the Blade Element Momentum Theory follows the step by step as described by Hansen work well for these three blade models. However a little adjustment on the blade data is needed. To the case of two bladed horizontal axis wind

Hydrodynamic Analysis of the Sweeping of a "Ro"—an Oriental Scull

1989 ◽  
Vol 33 (01) ◽  
pp. 47-62
Author(s):  
Akira Azuma ◽  
Toyohiko Furuta ◽  
Matsusaburo luchi ◽  
Isao Watanabe
Keyword(s):  
Experimental Studies ◽  
Hydrodynamic Characteristics ◽  
Local Circulation ◽  
Hydrodynamic Analysis ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Long Time ◽  
Optimal Efficiency ◽  
Element Theory ◽  
Blade Element

The "ro" and "kai" are kinds of oriental sculls used to propel and to steer small boats and have been utilized for a long time in Japan. Analytic and experimental studies are performed to understand the mechanisms of locomotion of the ro and kai. Simple momentum theory and the local circulation method, together with the blade element theory, are applied to obtain the hydrodynamic characteristics of the ro and these are compared with experimental test data. The results show that the matching of the ro with the hull is excellent in the hydrodynamic sense and that the operation of the ro is also conducted with optimal efficiency.

Analysis of Propeller Design Methods and Validation With the CFD Computation of a Propeller-Pump

2012 ◽  
Author(s):  
Sven Albert ◽  
Philipp Epple ◽  
Antonio Delgado
Keyword(s):  
Axial Motion ◽  
Blade Element Theory ◽  
Momentum Theory ◽  
Propeller Design ◽  
Reliable Design ◽  
Operational Range ◽  
Propeller Performance ◽  
Element Theory ◽  
Good Agreement ◽  
Blade Element

There is a large variety of axial propellers available, ranging from very small devices with only millimeters in diameter to ship propellers being several meters in size. Also they are applicable in several different ways, from low pressure propellers when actually used as fans or high pressure differences when used for propulsion purposes. Several theories have been developed to calculate and predict propeller performance. The basic theory is the linear momentum theory which takes only the axial motion into account. The theory can be refined taking the rotational motion and hence the angular momentum into account and also segmenting the propeller into several blade elements, to which classical airfoil theory can be applied. However, common literature does not include any precise verification of these theories. The present work shows with CFD computations the validation and hence accuracy of the blade element theory and its predecessors on a specific axial machine, namely the blood assist Reitan catheter propeller-pump. The propeller-pump is evaluated in a large operational range, using a commercial CFD code. The theory is then applied to the CFD results calculating the stream tube, in which all the necessary parameters, like interference factors, are evaluated. Those will deliver the machine characteristics thrust, torque and efficiency according to these theories. Comparison of this data to the CFD values shows good agreement, especially when segmenting the propeller and therefore using multiple stream tubes. Thus, the validity of these theories and its range of applicability was verified showing in detail how these theories can be employed as reliable design tools coupled with CFD verification.

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