Study on the effects of winglets: wind turbine blades having circular arc blade section profile

Abstract. Monitoring the flow features over wind turbine blades is a challenging task that has become more and more crucial. This paper is devoted to demonstrate the ability of the e-TellTale sensor to detect the flow stall/reattachment dynamics over wind turbine blades. This sensor is made of a strip with a strain gauge sensor at its base. The velocity field was acquired using TR-PIV measurements over an oscillating 2D blade section equipped with an e-TellTale sensor. PIV images were post-processed to detect movements of the strip, which was compared to movements of flow. Results show good agreement between the measured velocity field and movements of the strip regarding the stall/reattachment dynamics.

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A Numerical Study of Wind Turbine Airfoil Combined Oscillations Considering Phase Difference under Yaw Loads

10.21203/rs.3.rs-24680/v1 ◽

2020 ◽

Author(s):

Yufeng Yin ◽

Zhengjie Ji ◽

Jin Zhang ◽

Xuan Yin ◽

Yijie Feng ◽

...

Keyword(s):

Wind Turbine ◽

Phase Difference ◽

Numerical Study ◽

Turbine Blades ◽

Aerodynamic Performance ◽

Operating Efficiency ◽

Wind Turbine Blades ◽

Pitching Motion ◽

Blade Section ◽

Wind Turbine Airfoil

Abstract In order to further improve the operating efficiency of wind turbines and explore the aerodynamic performance of the complex motion of wind turbine blades under yaw loads. In this study, the change in the angle of attack of the blade section airfoil under yaw load can be modeled as an oscillating airfoil and combined with the blade's flapwise motion. The NREL S809 airfoil are chosen for the research, based on the SST k-ω turbulence model with transition correction, under the condition of Reynolds number of 10 6 . The effect of phase difference on its aerodynamic performance under combined flapwise and pitching motion in various flapwise amplitudes and working conditions were analyzed. For the combined oscillations, the effects of the flapwise amplitude ( h ) in the range of 0.2≤ h ≤0.5 are investigated with the phase differences of Φ=±3π/4, ±π/2, ±π/4, 0. The results show that the phase difference between the pitching motion and the flapping motion and the different flapping amplitudes can have a large impact on the aerodynamic performance of the airfoil during dynamic stall, but the degree of influence is greatly different in different situations.

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Transient atmospheric ice accretion on wind turbine blades

Wind Engineering ◽

10.1177/0309524x18780380 ◽

2018 ◽

Vol 42 (6) ◽

pp. 596-606

Author(s):

Galal M Ibrahim ◽

Kevin Pope ◽

Yuri S Muzychka

Keyword(s):

Wind Turbine ◽

Water Content ◽

Liquid Water ◽

Turbine Blades ◽

Liquid Water Content ◽

Single Shot ◽

Ice Accretion ◽

Wind Turbine Blades ◽

Median Volume ◽

Blade Section

This article aims to predict ice loads on a wind turbine blade section at 80% of blade span, using FENSAP ICE. Using low and high liquid water content conditions of stratiform and cumuliform clouds, different icing events are simulated. Ice accretion predictions with single-shot and multi-shot approaches are presented. Blade surface roughness is also investigated, as well as the relationships between ice mass, liquid water content, median volume diameter, and temperature.

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Low-Reynolds-number investigations on the ability of the strip of e-TellTale sensor to detect the flow features over wind turbine blade section: flow stall and reattachment dynamics

Wind Energy Science ◽

10.5194/wes-6-409-2021 ◽

2021 ◽

Vol 6 (2) ◽

pp. 409-426

Author(s):

Antoine Soulier ◽

Caroline Braud ◽

Dimitri Voisin ◽

Bérengère Podvin

Keyword(s):

Velocity Field ◽

Wind Turbine ◽

Turbine Blades ◽

Wind Turbine Blades ◽

Time Resolved ◽

Measured Velocity ◽

Piv Measurements ◽

Image Velocimetry ◽

Flow Features ◽

Blade Section

Abstract. Monitoring the flow features over wind turbine blades is a challenging task that has become more and more crucial. This paper is devoted to demonstrate the ability of the e-TellTale sensor to detect the flow stall–reattachment dynamics over wind turbine blades. This sensor is made of a strip with a strain gauge sensor at its base. The velocity field was acquired using time-resolved particle image velocimetry (TR-PIV) measurements over an oscillating 2D blade section equipped with an e-TellTale sensor. PIV images were post-processed to detect movements of the strip, which was compared to movements of flow. Results show good agreement between the measured velocity field and movements of the strip regarding the stall–reattachment dynamics.

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Research on the Parametric Modelling Approach of Vortex Generator on Wind Turbine Airfoil

Frontiers in Energy Research ◽

10.3389/fenrg.2021.726721 ◽

2021 ◽

Vol 9 ◽

Author(s):

Ming Chen ◽

Zhenzhou Zhao ◽

Huiwen Liu ◽

Tongguang Wang ◽

Lingyu Meng ◽

...

Keyword(s):

Wind Turbine ◽

Pressure Coefficient ◽

Turbine Blades ◽

Vortex Generator ◽

Parametric Model ◽

Parametric Models ◽

Parametric Modelling ◽

Wind Turbine Blades ◽

Blade Section ◽

Research Efficiency

Counter-rotating vortex generators (VGs) are typically employed to delay airflow separation on wind turbine blades. Large-size wind turbine blades equipped with small size VGs make the computational fluid dynamics (CFD) researches require a great deal of computational resources. Parametric models of VGs can effectively improve the numerical research efficiency of wind turbine blades with VGs. In order to improve the accuracy of such parametric models, this study proposed a series of modeling approaches to determine the positions of the adding source term in Cartesian coordinates, the VG vortex core radius, etc., on the wind turbine airfoils. These techniques are integrated with a maximum circulation algorithm by considering the interactions between VG pairs to predict the performance of a DU91-W2-250 blade section with VGs. The proposed parametric model and an entity model at different angles of attack (AoAs) are implemented on the blade section. Our approach is validated using experimental data. Comparisons demonstrate a strong agreement between the modelled and experimental results, proving the high accuracy of the two models. The numerical results of the models are then compared and analyzed at different incoming flow velocities and AoAs to verify the universality of the proposed parametric approaches. The results reveal a high consistency between the vortex structure, the velocity profile above the blade surface and the distribution of the pressure coefficient calculated by the two models. This proves the high universality of the proposed approaches and demonstrates the potential of the parametric model in replacing the VG entity model. The VG parametric model expresses VG parameters by program, which can improve the research efficiency of VG arrangement on wind turbine blades.

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