Flow angle measurement of a yawed turbine and comparison to models

Abstract

Abstract. The torque generated by a wind turbine blade is dependent on several parameters, one of which is the angle of attack.Several models for predicting the angle of attack in yawed conditions have been proposed in the literature, but there is a lack of experimental data to use for direct validation.To address this problem, experiments were conducted under controlled conditions at the University of Waterloo Wind Generation Research Facility using a 3.4 m diameter test turbine. A five-hole pressure probe was installed in a modular 3D printed These five-hole probe measurements were also used to characterize the upstream flow profile. Wind speeds determined using the five-hole probe measurements are presented and are in agreement with measurements obtained in the wind facility during testing. The quality of results indicates the potential of the developed instrument for wind turbine measurements.

Dynamic Stall on Pitching Cambered Airfoil with Phase Offset Trailing Edge Flap

“…. This wide range of α was chosen to replicate the same range that wind turbine blades experience [43,44]. Both coefficients are determined by integrating the differential coefficient of pressure (∆(C p )) along the chord of the airfoil from the 27 differential pressure transducers.…”

“…Morote [41] and Burton et al [42] modeled the α variation as a function of azimuthal position. Gallant and Johnson [43] compared those previous two models to experimental data on a 3.4 m diameter HAWT. From the models and experiments it was found that the α variation is very similar to a sinusoidal path when the turbine is yawed.…”

“…The measured angle of attack (α) ranged from -5 • to 50 • in steps of 1 • and the flap angle (α F ) from -20 • to 20 • in steps of 10 • . This wide range of α was chosen to replicate the same range that wind turbine blades experience[43,44]. Both…”

Deep dynamic stall and active aerodynamic modification on a S833 airfoil using pitching trailing edge flap

“…The results published by Gallant and Johnson (2017) indicate that when an operating wind turbine is yawed, the mean oscillating α could be 25 • while the amplitude could be 5 • under certain conditions. Case 2 in this paper aims to simulate a wind turbine blade under the same conditions mentioned in Gallant and Johnson.…”

“…In some operating conditions, a percentage of the wind turbine blade span could be experiencing α values higher than 30 • . Gallant and Johnson (2017) measured α on a wind turbine blade operating under yaw conditions to be oscillating around a mean α of 25 • with an amplitude of 5 • . Most of the papers and references presented so far study the dynamic stall cycle where the maximum pitch angle is 25 • .…”