Abstract
In this report we calculated the effects of flow nonuniformities (wind shear, tower wake, yaw, and large-scale turbulence) on the performance of a horizontal axis wind turbine, accounting for dynamic stall. We modified the PROP program to incorporate and compare these effects with the uniform flow case. The MIT model, which predicts dynamic lift coefficients substantially higher than the staticmaximum values and includes a crude model of the vortex roll-off phenomenon, represented dynamic stall. An associated model for drag was also used. The dynamic stall model was also tested against experimental data for three typical reduced frequencies. Good instantaneous correlation was obtained. The effects of nonuniformities with and without the dynamic stall were calculated using theWestinghouse Mod 0 and Enertech 44/25 turbines. Modeling the dynamic stall had little effect on performance. Furthermore, the performance with nonuniform flow differed only slightly from the uniform flow case. Thus the now PROP model provides a powerful general capability to handle nonuniform flows.
Original language | American English |
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Number of pages | 88 |
State | Published - 1986 |
Bibliographical note
Work performed by AeroVironment, Inc., Monrovia, CaliforniaNREL Publication Number
- NREL/STR-217-2732
Keywords
- air flow
- airfoils
- computer codes
- drag
- turbine blades
- wind turbines