Acoustic Characterization of a Quadcopter Using a Test Stand

Unmanned Aerial Vehicles (UAVs) with multirotor propulsion and control, commonly referred to as drones, generate a complex acoustic field that is not entirely understood. Many components and their interactions contribute to the overall noise level and behavior of the acoustic field. A UAV test stand configured to emulate a small quadcopter was used to determine the acoustic response of a multicopter. Microflown Technologies Scan & Paint 3D solution was utilized to obtain sound pressure, particle velocity, and sound intensity measurements close to the source, along with propagation planes for three-dimensional visualizations containing both amplitude and direction. Draw-away measurements using a PU probe were also completed to analyze the sound field characteristics further from the source. The number of propellers in operation was varied to determine the impact of adding additional sources. Aeroacoustic sources, near and far field behavior, interaction noise, directivity, and sound field propagation are discussed.