Wind Turbine Wake Effect Visualization And LiDAR Measurement Techniques

The expansion of wind energy development has resulted in larger wind farms and closer placement of turbines to utilize the space available. Each turbine produces a wake that affects downstream turbines, which causes issues such as production loss, blade loading, and fluctuating electrical output. In order to minimize this impact, the wake produced by turbines must first be understood. Experimental methods were used in the exploration of the wake effects of wind turbines. Smoke visualization inside a controlled wind facility was used to determine the helical vortex wake distribution behind a 3.3 m diameter turbine as well as the tip vortex shedding on the blade. Wind Doppler Light Detection and Ranging (LiDAR) measurement devices are used to measure the velocity of aerosols to determine the wind velocity. This technique can be used to measure the airspeed in the wake of a wind turbine. The University of Waterloo Wind Energy Group has a ZephIR z150 LiDAR to use in this study. The LiDAR was verified for accuracy against a cup and vane anemometer. The results determined that the LiDAR was suitable to provide accurate measurements in further turbine wake experiments. The University of Waterloo’s facilities provide the advantage to study wake effects under controlled wind conditions as well as under realistic open-air conditions.