The role of large scales of turbulence in wind turbine blades at various angles of attack

Sheilla Torres-Nieves, Victor Maldonado, Luciano Castillo, Charles Meneveau, Hyung Suk Kang

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Two-dimensional Particle Image Velocimetry (2-D PIV) measurements were performed to study the effect of free-stream turbulence (FST) on the flow around a smooth and rough surface airfoil, specifically under stall conditions. A 0.25-m chord model with an S809 profile, common for horizontal-axis wind turbine applications, was tested at a wind tunnel speed of 10 m/s, resulting in Reynolds numbers based on the chord of Rec ≈182,000 and turbulence intensity levels of up to 6.14%. Results indicate that when the flow is fully attached, turbulence significantly decreases aerodynamic efficiency (from L/D ≈ 4.894 to L/D ≈ 0.908). On the contrary, when the flow is mostly stalled, the effect is reversed and aerodynamic performance is slightly improved (from L/D ≈ 1.696 to L/D ≈ 1.787). Analysis of the mean flow over the suction surface shows that, contrary to what is expected, free-stream turbulence is actually advancing separation, at stall conditions, particularly when the turbulent scales in the free-stream are of the same order as the chord. This is a result of the complex dynamics between the boundary layer scales and the free-stream turbulence length scales when relatively high levels of active-grid generated turbulence are present.

Original languageEnglish
Title of host publication6th AIAA Theoretical Fluid Mechanics Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
ISBN (Print)9781624101441
DOIs
StatePublished - 2011
Event6th AIAA Theoretical Fluid Mechanics Conference - Honolulu, HI, United States
Duration: Jun 27 2011Jun 30 2011

Publication series

Name6th AIAA Theoretical Fluid Mechanics Conference

Conference

Conference6th AIAA Theoretical Fluid Mechanics Conference
CountryUnited States
CityHonolulu, HI
Period06/27/1106/30/11

Fingerprint Dive into the research topics of 'The role of large scales of turbulence in wind turbine blades at various angles of attack'. Together they form a unique fingerprint.

Cite this