scholarly journals Detailed analysis of the blade root flow of a horizontal axis wind turbine

2016 ◽  
Vol 1 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Iván Herráez ◽  
Buşra Akay ◽  
Gerard J. W. van Bussel ◽  
Joachim Peinke ◽  
Bernhard Stoevesandt
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Aerodynamic Performance ◽  
Negative Influence ◽  
Navier Stokes ◽  
Wind Turbine Blades ◽  
Force Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Blade Root ◽  
Root Region

Abstract. The root flow of wind turbine blades is subjected to complex physical mechanisms that influence significantly the rotor aerodynamic performance. Spanwise flows, the Himmelskamp effect, and the formation of the root vortex are examples of interrelated aerodynamic phenomena that take place in the blade root region. In this study we address those phenomena by means of particle image velocimetry (PIV) measurements and Reynolds-averaged Navier–Stokes (RANS) simulations. The numerical results obtained in this study are in very good agreement with the experiments and unveil the details of the intricate root flow. The Himmelskamp effect is shown to delay the stall onset and to enhance the lift force coefficient Cl even at moderate angles of attack. This improvement in the aerodynamic performance occurs in spite of the negative influence of the mentioned effect on the suction peak of the involved blade sections. The results also show that the vortex emanating from the spanwise position of maximum chord length rotates in the opposite direction to the root vortex, which affects the wake evolution. Furthermore, the aerodynamic losses in the root region are demonstrated to take place much more gradually than at the tip.

scholarly journals Detailed Analysis of the Blade Root Flow of a Horizontal Axis Wind Turbine

2016 ◽  
Author(s):  
I. Herráez ◽  
B. Akay ◽  
G. J. W. van Bussel ◽  
J. Peinke ◽  
B. Stoevesandt
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Wind Turbine Blades ◽  
Force Coefficient ◽  
Horizontal Axis Wind Turbine ◽  
Physical Mechanisms ◽  
Blade Root ◽  
Root Region ◽  
Image Velocimetry

Abstract. The root flow of wind turbine blades is subjected to complex physical mechanisms that influence significantly the rotor aerodynamic performance. Spanwise flows, the Himmelskamp effect and the formation of the root vortex are examples of interrelated aerodynamic phenomena observed in the blade root region. In this study we address those phenomena by means of Particle Image Velocimetry (PIV) measurements and Reynolds Averaged Navier–Stokes (RANS) simulations. The numerical results obtained in this study are in very good agreement with the experiments and unveil the details of the intricate root flow. The Himmelskamp effect is shown to delay the stall onset and enhance the lift force coefficient Cl even at a moderate angle of attack (AoA ≈ 13°). The results also show that the vortex emanating from the spanwise position of maximum chord length rotates in the opposite direction of the root vortex, what affects the wake evolution.

Analysis of Blunt Trailing Edge Airfoils

2003 ◽  
Author(s):  
K. J. Standish ◽  
C. P. van Dam
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Computational Techniques ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Blunt Trailing Edge ◽  
Large Wind ◽  
Structural Volume

The adoption of blunt trailing edge airfoils for the inner regions of large wind turbine blades has been proposed. Blunt trailing edge airfoils would not only provide increased structural volume, but have also been found to improve the lift characteristics of airfoils and therefore allow for section shapes with a greater maximum thickness. Limited experimental data makes it difficult for wind turbine designers to consider and conduct tradeoff studies using these section shapes. This lack of experimental data precipitated the present analysis of blunt trailing edge airfoils using computational fluid dynamics. Several computational techniques are applied including a viscous/inviscid interaction method and several Reynolds-averaged Navier-Stokes methods.

scholarly journals Numerical Simulation of Aerodynamic Performance of Off-grid Small Vertical Axis Wind Turbine

2018 ◽  
Vol 53 ◽  
pp. 02004
Author(s):  
Qiuyun Mo ◽  
Jiabei Yin ◽  
Lin Chen ◽  
Weihao Liu ◽  
Li Jiang ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Velocity Fields ◽  
Compact Model ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
Rotation Domain ◽  
Rng Turbulence Model

In this paper, a 2D off-grid small compact model of vertical axis wind turbine was established. The sliding grid technology, the RNG turbulence model and the Coupld algorithm was applied to simulate the unsteady value of the model's aerodynamic performance. Through the analysis on the flow field at difference moments, the rules about velocity fields, vortices distributions and the wind turbine's total torque were obtained. The results show that: the speed around wind turbine blades have obvious gradient, and the velocity distribution at different times show large differences in the computional domain. In the rotating domain vorticity is large. With away from the rotation domain, vorticity reduced quickly. In the process of rotating for vertical axis wind turbine, the wind turbine's total torque showed alternating positive and negative changes.

Optimization of Aerodynamic Performance of Wind Turbine Blades

2013 ◽  
Vol 284-287 ◽  
pp. 518-522
Author(s):  
Hua Wei Chi ◽  
Pey Shey Wu ◽  
Kami Ru Chen ◽  
Yue Hua Jhuo ◽  
Hung Yun Wu
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Wind Power Generation ◽  
Generation System ◽  
Wind Turbine Blades ◽  
Rotor Design ◽  
Power Generation System

A wind-power generation system uses wind turbine blades to convert the kinetic energy of wind to drive a generator which in turn yields electricity, the aerodynamic performance of the wind turbine blades has decisive effect on the cost benefit of the whole system. The aerodynamic analysis and the optimization of design parameters for the wind turbine blades are key techniques in the early stage of the development of a wind-power generation system. It influences the size selection of connecting mechanisms and the specification of parts in the design steps that follows. A computational procedure and method for aerodynamics optimization was established in this study for three-dimensional blades and the rotor design of a wind turbine. The procedure was applied to improving a previously studied 25kW wind turbine rotor design. Results show that the aerodynamic performance of the new three-dimensional blades has remarkable improvement after optimization.

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