Abstract
Wind turbines are subjected to dynamic loading from a variety of different sources. Wind shear and turbulence cause time-varying inflow that results in unsteady airloads. Tower shadow, upwind turbine wakes, and yaw angles also introduce unsteady inflow to wind turbine rotors. Wind turbine designers must predict these loads accurately in order to adequately design blades, hubs, and the remainingsupport structure to achieve a 30-year life. Structural analysts have not been able to predict mean or dynamic loads accurately enough to predict the fatigue life of major wind turbine components with confidence. Part of the problem is due to uncertainty in the stochastic wind environment as mentioned earlier. Another important part of the problem is the lack of basic knowledge of rotary wingairfoil stall performance. There is mounting evidence that dynamic stall may be related to dynamic loads that are greater than predictions. This paper describes some results of investigations of unsteady aerodynamic loads measured on a wind turbine blade. The objective of the investigation is to understand the steady and unsteady stall behavior of wind turbine blades.
Original language | American English |
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Number of pages | 15 |
State | Published - 1992 |
NREL Publication Number
- NREL/TP-257-4654
Keywords
- stall behavior
- unsteady aerodynamic loads
- wind turbine blades