Effects of reduced frequency on the performance of a wind turbine blade in the low and high turbulent unsteady flow

Soltani, M. R ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. DOI: 10.2514/6.2008-6582
  3. Publisher: American Institute of Aeronautics and Astronautics Inc , 2007
  4. Abstract:
  5. An extensive experimental study is conducted to investigate the effects of reduced frequency on a harmonically pitching wing where its cross section is used in a 660 kW wind turbine under construction in Iran. The corresponding lift coefficient and real time pressure signatures at three sections of the model at various reduced frequencies are examined. The test covers a wide range of angles of attack at prestall, stall, and deep stall regions. Pressure distributions at tip, middle, and root sections of the wing were recorded and from these distributions the lift coefficients are computed. The results show great role of the reduced frequency in altering the maximum lift coefficients, lift curve slopes, width of hysteresis loops, delaying the onset of separation and figure eight phenomenon. Further, it delays dynamic stall to higher angles of attack and changes its severity at different reduced frequencies. In addition, a turbulence screen was added and the aforementioned tests were repeated for this case. The results show that adding turbulence gird reduces the lift coefficient and delays the onset of separation and dynamic stall phenomena
  6. Keywords:
  7. Angle measurement ; Pressure distribution ; Turbomachine blades ; Turbulent flow ; Unsteady flow ; Lift coefficients ; Lift curve slopes ; Wind turbine blades ; Wind turbines
  8. Source: 25th AIAA Applied Aerodynamics Conference, 2007, Miami, FL, 25 June 2007 through 28 June 2007 ; Volume 2 , 2007 , Pages 877-882 ; 10485953 (ISSN); 1563478986 (ISBN); 9781563478987 (ISBN)
  9. URL: https://arc.aiaa.org/doi/10.2514/6.2008-6582