Full-Scale Wind Turbine Rotor Aerodynamics Research

The United States Department of Energy and the National Renewable Energy Laboratory (NREL) are conducting research to improve wind turbine technology at the NREL National Wind Technology Center (NWTC). One program, the Combined Experiment, has focused on making measurements; needed to understand aerodynamic and structural responses of horizontal-axis wind turbines (HAWT). A new phase of thisprogram, the Unsteady Aerodynamics Experiment, will focus on quantifying unsteady aerodynamic phenomena prevalent in stall-controlled HAWTs. Optimally twisted blades and innovative instrumentation and data acquisition systems will be used in these tests. Data can now be acquired and viewed; interactively during turbine operations. This paper describes the NREL Unsteady Aerodynamics Experimentand highlights planned future research activities.