Unsteady aerodynamic characteristics of a horizontal wind turbine under yaw and dynamic yawing

Horizontal axis wind turbine (HAWT) often works under yaw due to the stochastic variation of wind direction. Yaw also can be used as one of control methods for load reduction and wake redirection of HAWT. Thus, the aerodynamic performance under yaw is very important to the design of HAWT. For further insight into the highly unsteady characteristics aerodynamics of HAWT under yaw, this paper investigates the unsteady variations of the aerodynamic performance of a small wind turbine under static yawed and yawing process with sliding grid method, as well as the there-dimensional effect on the unsteady characteristics, using unsteady Reynolds-averaged Navier–Stokes (URANS) simulations. The simulation results are validated with experimental data and blade element momentum (BEM) results. The comparisons show that the CFD results have better agreement with the experimental data than both BEM results. The wind turbine power decreases according to a cosine law with the increase of yaw angle. The torque under yaw shows lower frequency fluctuations than the non-yawed condition due to velocity component of rotation and the influence of spinner. Dynamic yawing causes larger fluctuate than static yaw, and the reason is analyzed. The aerodynamic fluctuation becomes more prominent in the retreating side than that in the advancing side for dynamic yawing case. Variations of effective angle of attack and aerodynamic forces along the blade span are analyzed. The biggest loading position moves from middle span to outer span with the increase of yaw angle. Three-dimensional stall effect presents load fluctuations at the inner board of blade, and becomes stronger with the increase of yaw angle.

[1]  M. Shirakashi,et al.  Vortex Excited Oscillation of a Circular Cylinder in a Uniform Flow , 1984 .

[2]  David A. Peters,et al.  Review of dynamic inflow modeling for rotorcraft flight dynamics , 1986 .

[3]  David A. Peters,et al.  Dynamic inflow for practical applications , 1988 .

[4]  David A. Peters,et al.  Technical Note: Dynamic Inflow for Practical Applications , 1988 .

[5]  D. M. Somers,et al.  Design and experimental results for the S809 airfoil , 1997 .

[6]  M. Selig,et al.  A 3-D stall-delay model for horizontal axis wind turbine performance prediction , 1998 .

[7]  A. Suzuki.  Application of dynamic inflow theory to wind turbine rotors , 2000 .

[8]  Maureen Hand,et al.  Unsteady Aerodynamics Experiment Phase VI: Wind Tunnel Test Con gurations and Available Data Campaigns , 2001 .

[9]  M. L. Buhl,et al.  New Empirical Relationship between Thrust Coefficient and Induction Factor for the Turbulent Windmill State , 2005 .

[10]  Lakshmi N. Sankar,et al.  Numerical Simulation of the Aerodynamics of Horizontal Axis Wind Turbines under Yawed Flow Conditions , 2005 .

[11]  Tonio Sant,et al.  Improving BEM-based Aerodynamic Models in Wind Turbine Design Codes , 2007 .

[12]  Daniel Micallef,et al.  Final report of IEA Task 29, Mexnext (Phase 1): Analysis of Mexico wind tunnel measurements , 2012 .

[13]  Carlos Simao Ferreira,et al.  An investigation of radial velocities for a horizontal axis wind turbine in axial and yawed flows , 2013 .

[14]  Min-Soo Jeong,et al.  The impact of yaw error on aeroelastic characteristics of a horizontal axis wind turbine blade , 2013 .

[15]  Oh Joon Kwon,et al.  Numerical investigation of unsteady aerodynamics of a Horizontal‐axis wind turbine under yawed flow conditions , 2013 .

[16]  Shun Kang,et al.  Predictions of unsteady HAWT aerodynamics in yawing and pitching using the free vortex method , 2014 .

[17]  Christian Oliver Paschereit,et al.  Utility Scale Wind Turbine Yaw From a Flow Visualization View , 2015 .

[18]  Rafic Younes,et al.  Review of performance optimization techniques applied to wind turbines , 2015 .

[19]  G. Bussel,et al.  Experimental and numerical investigation of tip vortex generation and evolution on horizontal axis wind turbines , 2016 .

[20]  Daniel Micallef,et al.  A Review of Wind Turbine Yaw Aerodynamics , 2016 .

[21]  Ki-Wahn Ryu,et al.  Prediction of Aerodynamic Loads for NREL Phase VI Wind Turbine Blade in Yawed Condition , 2016 .

[22]  W. Tian,et al.  Experimental investigation on the wake interference among wind turbines sited in atmospheric boundary layer winds , 2017 .

[23]  Ewald Krämer,et al.  CFD study on the impact of yawed inflow on loads, power and near wake of a generic wind turbine , 2017 .

[24]  G. Barakos,et al.  10-MW Wind Turbine Performance Under Pitching and Yawing Motion , 2017 .

[25]  Youshi Hong,et al.  Effects of tension on vortex-induced vibration (VIV) responses of a long tensioned cylinder in uniform flows , 2017 .

[26]  Xiaodong Wang,et al.  Analysis of wind turbine blades aeroelastic performance under yaw conditions , 2017 .

[27]  Xiao-dong Wang,et al.  Numerical simulations of flow interactions between steep hill terrain and large scale wind turbine , 2018 .

[28]  J. Dai,et al.  Effect investigation of yaw on wind turbine performance based on SCADA data , 2018 .

[29]  Chun Li,et al.  Numerical investigations on control strategies of wake deviation for large wind turbines in an offshore wind farm , 2019, Ocean Engineering.

[30]  Zhike Peng,et al.  A numerical study on the angle of attack to the blade of a horizontal-axis offshore floating wind turbine under static and dynamic yawed conditions , 2019, Energy.

[31]  Shun Kang,et al.  Investigations on the Unsteady Aerodynamic Characteristics of a Horizontal-Axis Wind Turbine during Dynamic Yaw Processes , 2019, Energies.

[32]  Hui Hu,et al.  Numerical Study of Nacelle Wind Speed Characteristics of a Horizontal Axis Wind Turbine under Time-Varying Flow , 2019, Energies.