scholarly journals Estimating the Unsteady Angle of Attack from Blade Pressure Measurments on the NREL Phase VI Rotor in Yaw using a Free-Wake Vortex Model

2006 ◽  
Author(s):  
Tonio Sant ◽  
G.A.M. van Kuik ◽  
G.J.W. van Bussel
Keyword(s):  
Angle Of Attack ◽  
Wake Vortex ◽  
Vortex Model ◽  
Nrel Phase Vi ◽  
Free Wake

scholarly journals A Modified Free Wake Vortex Ring Method for Horizontal-Axis Wind Turbines

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3900 ◽  
Author(s):  
Jing Dong ◽  
Axelle Viré ◽  
Carlos Simao Ferreira ◽  
Zhangrui Li ◽  
Gerard van Bussel
Keyword(s):  
Wind Turbine ◽  
Vortex Ring ◽  
Horizontal Axis ◽  
Wake Vortex ◽  
Horizontal Axis Wind Turbine ◽  
Vortex Model ◽  
Ring Method ◽  
Wake Model ◽  
Free Wake ◽  
Platform Motions

A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine, which is divided into two parts. The near wake model uses a blade bound vortex model and trailed vortex model, which is developed based on vortex filament method with straight lifting lines assumption. By contrast, the far wake model is based on the vortex ring method. The proposed model is a good compromise between accuracy and computational cost, for example when compared with more complex vortex methods. The present model is used to assess the influence of floating platform motions on the performance of a horizontal-axis wind turbine rotor. The results are validated on the 5 MW NREL rotor and compared with other aerodynamic models for the same rotor subjected to different platform motions. The results show that the proposed method is reliable. In addition, the proposed method is less time consuming and has similar accuracy when comparing with more advanced vortex based methods.

scholarly journals Dynamic prescribed-wake vortex method for aerodynamic analysis of offshore floating wind turbines

2018 ◽  
Vol 43 (1) ◽  
pp. 47-63
Author(s):  
Jeanie Aird ◽  
Evan Gaertner ◽  
Matthew Lackner
Keyword(s):  
Vortex Method ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wake Vortex ◽  
Analysis Tool ◽  
Vortex Model ◽  
Comparable Accuracy ◽  
Wake Model ◽  
Turbine Design ◽  
Free Wake

A prescribed-wake vortex model for evaluating the aerodynamic loads on offshore floating turbines has been developed. As an extension to the existing UMass analysis tool, WInDS, the developed model uses prescribed empirical wake node velocity functions to model aerodynamic loading. This model is applicable to both dynamic flow conditions and dynamic rotational and translational platform motions of floating offshore turbines. With this model, motion-induced wake perturbations can be considered, and their effect on induction can be modeled, which is useful for floating offshore wind turbine design. The prescribed-wake WInDS model is shown to increase computational efficiency drastically in all presented cases and maintain comparable accuracy to the free wake model. Results of prescribed-wake model simulations are presented and compared to results obtained from the free wake model to confirm model validity.

Influence of Rigid Body Motions on Rotor Induced Velocities and Aerodynamic Loads of a Floating Horizontal Axis Wind Turbine

2014 ◽  
Author(s):  
Jacobus B. de Vaal ◽  
Martin O. L. Hansen ◽  
Torgeir Moan
Keyword(s):  
Rigid Body ◽  
Wind Turbine ◽  
Horizontal Axis ◽  
Simplified Model ◽  
Wake Vortex ◽  
Horizontal Axis Wind Turbine ◽  
Aerodynamic Loads ◽  
Vortex Model ◽  
Rigid Body Motions ◽  
Free Wake

This paper discusses the influence of rigid body motions on rotor induced velocities and aerodynamic loads of a floating horizontal axis wind turbine. Analyses are performed with a simplified free wake vortex model specifically aimed at capturing the unsteady and non-uniform inflow typically experienced by a floating wind turbine. After discussing the simplified model in detail, comparisons are made to a state of the art free wake vortex code, using test cases with prescribed platform motion. It is found that the simplified model compares favourably with a more advanced numerical model, and captures the essential influences of rigid body motions on the rotor loads, induced velocities and wake influence.

A Modified Free-Wake Vortex Ring Model for the Aerodynamics of Floating Offshore Wind Turbines

2019 ◽  
Author(s):  
Jing Dong ◽  
Axelle Viré ◽  
Simao Ferreira ◽  
Zhangrui Li ◽  
Gerard van Bussel
Keyword(s):  
Wind Turbine ◽  
Vortex Ring ◽  
Horizontal Axis ◽  
Wake Vortex ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Vortex Model ◽  
Ring Model ◽  
Wake Model ◽  
Free Wake

Abstract A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine. The model is divided into two parts. The near wake model uses a blade bound vortex model and trailed vortex model, which is developed based on vortex filament method. By contrast, the far wake model is based on the vortex ring method. This is a good compromise between accuracy and computational cost. In this work, the model is used to assess the influence of floating platform motions on the performance of a horizontal-axis wind turbine rotor. The results are validated on the 5MW NREL rotor and compared with other vortex models for the same rotor subjected to different platform motions. It was found that the result from the proposed method are more reliable than the results from BEM theory especially at small angles of attack in the region of low wind speeds, on the one hand, and high wind speeds with blade pitch motions, on the other hand.

scholarly journals A Modified Free Wake Vortex Ring Method for Horizontal-Axis Wind Turbines

2019 ◽  
Author(s):  
Jing Dong ◽  
Axelle Viré ◽  
Carlos Simao Ferreira ◽  
Zhangrui Li ◽  
Gerard van Bussel
Keyword(s):  
Wind Turbine ◽  
Vortex Ring ◽  
Horizontal Axis ◽  
Wake Vortex ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Vortex Model ◽  
Ring Method ◽  
Wake Model ◽  
Free Wake

A modified free-wake vortex ring model is proposed to compute the dynamics of a floating horizontal-axis wind turbine. The model is divided into two parts. The near wake model uses a blade bound vortex model and trailed vortex model, which is developed based on vortex filament method. By contrast, the far wake model is based on the vortex ring method. The proposed model is a good compromise between accuracy and computational cost, for example when compared with more complex vortex methods. The present model is used to assess the influence of floating platform motions on the performance of a horizontal-axis wind turbine rotor. The results are validated on the 5MW NREL rotor and compared with other aerodynamic models for the same rotor subjected to different platform motions. It was found that the results from the proposed method are more reliable than the results from BEM theory especially at small angles of attack in the region of low wind speeds, on the one hand, and high wind speeds with blade pitch motions, on the other hand. And also the proposed method is less time consuming and has similar accuracy when comparing with more advanced vortex based methods.

Numerical and experimental analysis on the helicopter rotor dynamic load controlled by the actively trailing edge flap

2022 ◽  
Author(s):  
zixuan zhou ◽  
Xiuchang Huang ◽  
Jiajin Tian ◽  
Hongxing Hua ◽  
Ming Tang ◽  
...  
Keyword(s):  
Dynamic Load ◽  
Peak Load ◽  
Angle Of Attack ◽  
Helicopter Rotor ◽  
Effective Control ◽  
Aerodynamic Load ◽  
Lattice Method ◽  
Minimum Angle ◽  
Free Wake ◽  
Rotor Dynamic

Abstract Reducing the rotor dynamic load is an important issue to improve the performance and reliability of a helicopter. The control mechanism of the actively controlled flap on the rotor dynamic load is numerically and experimentally investigated by a 3-blade helicopter rotor in this paper. In the aero-elastic numerical approach, the complex motion of the rotor such as the stretching, bending, torsion and pitching of the blade including the deflection of the actively controlled flap (ACF) are all taken into consideration in the structural formulation. The aerodynamic solution adopted the vortex lattice method combining with the free wake model, in which the influence of ACF on the free wake and the aerodynamic load on the blade is taken into account as well. While the experimental method of measuring hub loads and acoustic was accomplished by a rotor rig in a wind tunnel. The result shows that the 3/rev ACF actuation can reduce the $3\omega$ hub load by more than 50\% at maximum, which is significantly better than the 4/rev control. While 4/rev has greater potential to reduce BVI loads than 3/rev with $\mu=0.15$. Further mechanistic analysis shows that by changing the phase difference between the dynamic load on the flap and the rest of the blade, the peak load on the whole blade can be improved, thus achieving effective control of the hub dynamic load, the flap reaches the minimum angle of attack at 90°-100° azimuth under best control condition; when the BVI load is perfectly controlled, the flap reaches the minimum angle of attack at 140° azimuth, and by changing the circulation of the wake, the intensity of blade vortex interaction in the advancing side is improved. Moreover, an interesting finding in the optimal control of noise and vibration is that an overlap point exist on the motion patterns of the flap with different frequencies.

Simulation of wake vortex effects for UAVs in close formation flight

2009 ◽  
Vol 113 (1149) ◽  
pp. 727-738 ◽  
Author(s):  
D. Saban ◽  
J. F. Whidborne ◽  
A. K. Cooke
Keyword(s):  
Real Time ◽  
Formation Flying ◽  
Cross Coupling ◽  
Simulation Models ◽  
Formation Flight ◽  
Wake Vortex ◽  
Simulation Environment ◽  
Vortex Model ◽  
Simulink Simulation ◽  
Aerodynamic Interaction

AbstractThis paper addresses the development of multiple UAV deployment simulation models that include representative aerodynamic cross-coupling effects. Applications may include simulations of autonomous aerial refuelling and formation flying scenarios. A novel wake vortex model has been developed and successfully integrated within a Matlab/Simulink simulation environment. The wake vortex model is both sufficiently representative to support studies of aerodynamic interaction between multiple air vehicles, and straightforward enough to be used within real time or near real time air-to-air simulations. The model integration process is described, and computational results of a two-vehicle-formation flight are presented.

Sign in / Sign up

Export Citation Format

Share Document