Abstract
The primary goal of this investigation was to evaluate, in a repsresentative environment, the performance of several finite span trailing-edge aerodynamic control devices. A series of atmospheric tests were conducted at the National Renewable Energy Laboratory's National Wind Technology Center using an insturmented turbine, fit with variable span aerodynamic controls. Three different deviceconfigurations (spoiler-flap, vented aileron, and unvented aileron) and spans (7.5%, 15%, and 22.5%) were examined. Comprehensive turbine and atmospheric measurements were utilized to identify effective changes in the suction, lift, drag, and hinge moment coefficients as a function of angle-of-attack and device deflection. The tests were conducted at a chord Reynolds number of approximately 1million. Results are compared to supplied two-dimensional and infinite span wind tunnel data. The most pronounced lift behavior differences between the finite and infinite span data were for angles-of-attack around stall, where the three-dimensional variations were smoothed. Drag differences, as a function of span, appear to follow aspect ratio trends noted for similar geometries. On the basisof the investigation results, devices of 15% or greater span appear to behave in a predictable fashion relative to two-dimensional wind tunnel data.
Original language | American English |
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Number of pages | 45 |
State | Published - 1998 |
Bibliographical note
Work performed by Wichita State University, Wichita, Kansas, and Wind Turbine Engineering Consultant, Seattle, WashingtonNREL Publication Number
- NREL/SR-500-22350
Keywords
- blades
- horizontal-axis
- S809
- wind turbines