Wind Tunnel Testing to Evaluate Noise Emissions from a Small Wind Turbine

Abstract

The wind power industry has experienced fast and tremendous growth, globally, in recent years. Consequently, there is a growing interest in investigating aerodynamics and aeroacoustics characteristics of wind turbines and developing environmental standards aimed at decreasing noise levels in the design and manufacture of these machines.This study was carried out in the Carleton University Wind Induced Dynamic Laboratory (WInDLab) that was designed to evaluate and quantify noise levels emitted by a small horizontal axis wind turbine. This investigation provided the firstever set of measurements carried out in the WInDLab following the successful installation of the wind turbine.To achieve the objective of this project, first, the characterization of the wind tunnel had to be carried out. The wind velocity profile of the wind tunnel was characterized and results indicated that its profile is not perfectly symmetrical with respect to the tunnel centreline.The background noise levels of the WInDLab wind tunnel for different fan RPMs were recorded with a Brüel & Kjaer (B&K) Prepolarized Free-field Type 4189, ½"(1.27 cm) microphone, which was located at six positions in line with IEC61400-11 regulations. The noise measurements obtained were post-processed using the MATLAB software application. Plots for the sound pressure level (SPL) vs frequency of the wind turbine noise spectra, as well as the background noise level at 500 RPM, 575 RPM and 650 RPM of the wind tunnel fans were derived. I would like to express my sincere gratitude to my supervisors, Prof. Fred Afagh, Prof. Robert Langlois, and Prof. Joana Rocha for their advice, guidance, and financial support, in the course the project. A major part of my project work was the characterization of the wind tunnel and the acoustic noise measurements. I thank Mr. James Cann, Mr. Chris Bassindale, and Mr. David Raude, expert technologists in Carleton University's Mechanical and Aerospace Engineering Department who provided the support and guidance in the installation of the wind turbine, characterization of the wind tunnel, and the acoustic noise measurements of the wind tunnel. I thank Mr. Alex Proctor who assisted with the machining and assembling of the wind turbine tower. I am deeply grateful to my family for their unwavering support throughout the duration of this project. I thank my dad, my mom, my sisters and my brother for their prayers, encouragement, emotional support, financial support, and advice during my Master's degree program. I cannot forget Saeid Naeini for his help and ideas during the project. Lastly, I would like to thank all my friends who have supported me in one way or the other through the course of my project. v