Loading...

Experimental Investigation of Reduced Frequency Effects on the Boundary-Layer Profile of an Oscillating Airfoil in Pitching Motion

Ghorbani Shohrat, Faegheh | 2010

595 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 41145 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Soltani, Mohammad Reza
  7. Abstract:
  8. Application of wind energy and specially wind turbines as a green source of energy is getting more popular and as a result, the knowledge of wind energy has been improved dramatically. The purpose of this research is to determine the flow characteristics in the boundary layer profile over an airfoil which is used in a wind turbine blade. The model is sinusoidally oscillated in pitch. For the present study, the critical cross section of the wind turbine blade has been selected and the boundary layer velocity profiles over its airfoil have been investigated experimentally. Dynamic motion is produced with sinusoidal oscillator and the reduced frequency is varied in the range of 0.054 to 0.1. The Reynolds numbers were 0.47×106, 0.71×106 and 0.95×106. The model was pitched around its quarter chord point. For measuring the total pressure in the boundary layer, a special boundary layer rake has been designed and manufactured. Total pressure was measured in each test at two locations over the airfoil surface, x/c=0.37 and x/c=0.47. The results show that the reduced frequency has a main role on the behavior of the boundary layer profile over the airfoil. The B.L. profile was different in the upstoke and in the downstroke portions of the motions. In the pitch up phase of the motion, the boundary layer transition and separation phenomenon were delayed while during the pitch down motion the reattachment and relaminarization phenomenon were accelerated
  9. Keywords:
  10. Boundary Layer ; Unsteady Flow ; Reduced Frequency ; Wind Turbine ; Pitching Motion

 Digital Object List

  • محتواي پايان نامه
  •   view

 Bookmark

No TOC