Aerodynamic Performance of Wind Turbine Airfoil DU 91-W2-250 under Dynamic Stall

Airfoils are subjected to the ‘dynamic stall’ phenomenon in significant pitch oscillations during the actual operation process of wind turbines. Dynamic stall will result in aerodynamic fatigue loads and further cause a discrepancy in the aerodynamic performance between design and operation. In this paper, a typical wind turbine airfoil, DU 91-W2-250, is examined numerically using the transition shear stress transport (SST) model under a Reynolds number of 3 × 105. The influence of a reduced frequency on the unsteady dynamic performance of the airfoil model is examined by analyzing aerodynamic coefficients, pressure contours and separation point positions. It is concluded that an increasingly-reduced frequency leads to lower aerodynamic efficiency during the upstroke process of pitching motions. The results show the movement of the separation point and the variation of flow structures in a hysteresis loop. Additionally, the spectrum of pressure signals on the suction surface is analyzed, exploring the level of dependence of pressure fluctuation on the shedding vortex and oscillation process. It provides a theoretical basis for the understanding of the dynamic stall of the wind turbine airfoil.

[1]  N. D. Ham,et al.  Aerodynamic loading on a two-dimensional airfoil during dynamic stall. , 1968 .

[2]  F. J. Tarzanin,et al.  Prediction of Control Loads Due to Blade Stall , 1972 .

[3]  F. X. Caradonna,et al.  An Experimental Analysis of Dynamic Stall on an Oscillating Airfoil , 1974 .

[4]  H. Morowitz.  The phenomenon of man. , 1981, Hospital practice.

[5]  J. G. Leishman,et al.  A Semi-Empirical Model for Dynamic Stall , 1989 .

[6]  M. Raffel,et al.  Experimental and numerical investigations of dynamic stall on a pitching airfoil , 1996 .

[7]  J. Gordon Leishman,et al.  Principles of Helicopter Aerodynamics , 2000 .

[8]  P. Durbin,et al.  Statistical Theory and Modeling for Turbulent Flows , 2001 .

[9]  D. Drikakis,et al.  Computational study of unsteady turbulent flows around oscillating and ramping aerofoils , 2003 .

[10]  W. A. Timmer,et al.  Summary of the Delft University Wind Turbine Dedicated Airfoils , 2003 .

[11]  M. Akbari,et al.  Simulation of dynamic stall for a NACA 0012 airfoil using a vortex method , 2003 .

[12]  H. Madsen,et al.  A Beddoes-Leishman type dynamic stall model in state-space and indicial formulations , 2004 .

[13]  J. Gordon Leishman,et al.  Dynamic stall modelling of the S809 aerofoil and comparison with experiments , 2006 .

[14]  Markus Raffel,et al.  Micro-PIV and ELDV wind tunnel investigations of the laminar separation bubble above a helicopter blade tip , 2006 .

[15]  Steen Krenk,et al.  Dynamic Stall Model for Wind Turbine Airfoils , 2007 .

[16]  Joaquim Peiró,et al.  An assessment of some effects of the nonsmoothness of the Leishman–Beddoes dynamic stall model on the nonlinear dynamics of a typical aerofoil section , 2008 .

[17]  Frank N. Coton,et al.  A Modified Dynamic Stall Model for Low Mach Numbers , 2008 .

[18]  Yannick Hoarau,et al.  Turbulence modelling of the flow past a pitching NACA0012 airfoil at 105 and 106 Reynolds numbers , 2008 .

[19]  D. Favier,et al.  Dynamic Stall of a Pitching and Horizontally Oscillating Airfoil , 2009 .

[20]  G.A.M. van Kuik,et al.  Review of state of the art in smart rotor control research for wind turbines , 2010 .

[21]  Shengyi Wang,et al.  Numerical investigations on dynamic stall of low Reynolds number flow around oscillating airfoils , 2010 .

[22]  Zhang Xianmin,et al.  Dynamic Response Analysis of the Rotating Blade of Horizontal Axis Wind Turbine , 2010 .

[23]  Scott J. Johnson,et al.  An overview of active load control techniques for wind turbines with an emphasis on microtabs , 2010 .

[24]  Jianzhong Xu,et al.  Simulation of aerodynamic performance affected by vortex generators on blunt trailing-edge airfoils , 2010 .

[25]  Guy Dumas,et al.  Computational aeroelastic simulations of self-sustained pitch oscillations of a NACA0012 at transitional Reynolds numbers , 2011 .

[26]  Zhi Tao,et al.  Turbulence modeling of deep dynamic stall at relatively low Reynolds number , 2012 .

[27]  David A. Johnson,et al.  Numerical modeling of an S809 airfoil under dynamic stall, erosion and high reduced frequencies , 2012 .

[28]  Hester Bijl,et al.  Comparing different dynamic stall models , 2013 .

[29]  Kobra Gharali,et al.  Dynamic stall simulation of a pitching airfoil under unsteady freestream velocity , 2013 .

[30]  Maziar Arjomandi,et al.  An insight into the dynamic stall lift characteristics , 2014 .

[31]  Scott J. Johnson,et al.  An Innovative Design of a Microtab Deployment Mechanism for Active Aerodynamic Load Control , 2015 .

[32]  Lei Zhang,et al.  Effects of vortex generators on aerodynamic performance of thick wind turbine airfoils , 2016 .

[33]  Zheng-Tong Xie,et al.  Modelling the effect of freestream turbulence on dynamic stall of wind turbine blades , 2016 .

[34]  Javad Abolfazli Esfahani,et al.  Effect of acceleration on dynamic stall of airfoil in unsteady operating conditions , 2016 .

[35]  Z. Lei,et al.  Analyzing the effect of wind tunnel wall on the aerodynamic performance of airfoils , 2016 .

[36]  Ekaitz Zulueta,et al.  Five Megawatt Wind Turbine Power Output Improvements by Passive Flow Control Devices , 2017 .

[37]  Ekaitz Zulueta,et al.  Microtab Design and Implementation on a 5 MW Wind Turbine , 2017 .

[38]  Y. Peet,et al.  Effect of reduced frequency on dynamic stall of a pitching airfoil in a turbulent wake , 2017 .

[39]  Ekaitz Zulueta,et al.  Flow Control Devices for Wind Turbines , 2017 .

[40]  Cheng Lu,et al.  Vibration-induced aerodynamic loads on large horizontal axis wind turbine blades , 2017 .

[41]  Andrew Cashman,et al.  Numerical simulation of a vertical axis wind turbine airfoil experiencing dynamic stall at high Reynolds numbers , 2017 .