Year of Publication


Degree Name

Master of Science in Mechanical Engineering (MSME)

Document Type

Master's Thesis




Mechanical Engineering

First Advisor

Dr. Sean Bailey


In July of 2019, a flight campaign was conducted using semi-autonomous Unmanned Aerial Vehicles (UAVs) at the Port Alma Kruger Energy wind farm in Ontario, Canada, to study various aspects of wind turbine wake evolution. Horizontal transects across the wakes were measured using modified fixed-wing aircraft fitted with a five-hole probe to measure the wind velocity vector. Reference boundary layer conditions were measured by an octocopter with an assortment of mounted sensors flying vertical profiles upstream of the turbines. Three experiments were conducted during the campaign, which consisted of a study on wake behavior during the morning boundary layer transition, a comparison study between steered and unsteered wakes, and a wake steering study utilizing three aircraft flying in formation. These experiments demonstrated that wind turbine wakes experience increasing meandering and diffusion throughout boundary layer transition corresponding to the increase in boundary layer turbulence, and provided further support for utilizing wake steering to improve inflow conditions for downstream turbines. Such results demonstrate that UAVs can be an effective tool for measuring wind farm aerodynamics.

Digital Object Identifier (DOI)

Funding Information

This study was supported by the National Science Foundation through grant #CBET-1351411 initially awarded in 2014. This research was also supported by the National Science Foundation through award No.1539070 initially awarded in 2015. Both funding sources supported this research from May 2019 until December 2020.