Experimental Investigation on the Wake Characteristics and Aeromechanics of Dual Rotor Wind Turbines

Abstract

An experimental study was carried out to investigate the aeromechanics and wake characteristics of dualrotor wind turbines (DRWTs) in either corotating or counterrotating configuration, in comparison to those of a conventional singlerotor wind turbine (SRWT). The experiments were performed in a largescale aerodynamic/atmospheric boundary layer (AABL) wind tunnel, available at Iowa State University with the oncoming atmospheric boundarylayer (ABL) airflows under neutral stability conditions. In addition to measuring the power output performance of DRWT and SRWT models, static and dynamic wind loads acting on those turbine models were also investigated. Furthermore, a highresolution digital particle image velocimetry (PIV) system was used to quantify the flow characteristics in the near wakes of the DRWT and SRWT models. The detailed wakeflow measurements were correlated with the power outputs and windload measurement results of the windturbine models to elucidate the underlying physics to explore/optimize design of wind turbines for higher power yield and better durability.