MechE Seminar Series | Nathan Alexander

Speaker: Nathan Alexander

Title: The Noise Produced by Turbulence Interacting with Propellers

Abstract: There has been a resurgence of interest in propeller noise due to the advancement of drone and Advance Air Mobility (AAM) technologies. These vehicles are designed to operate within populated environments for on-demand delivery and transportation. Therefore, issues of public acceptance are critical if these technologies are to be successful. Noise, in particular, is at the forefront of concerns by impacted communities. Our research addresses the noise and performance of propellers in turbulent, non-stationary environments analogous to what a vehicle may experience flying near buildings in an urban landscape. This presentation will focus on work sponsored by ONR and NASA considering the interaction of propellers with large scale disturbances in axial and edgewise flight. The response of the propellers is decomposed into deterministic and stochastic components which align with similar components of the inflow. Dependence on operating condition (i.e. advance ratio) will be addressed as well as the development of future multi-rotor wind tunnel experiments.

About the Speaker: Dr. Nathan Alexander is an Associate Professor in the Department of Aerospace and Ocean Engineering at Virginia Tech. His expertise lies in experimental aero and hydroacoustics. His past work includes the study of noise from rotors, boundary layer flows, and acoustic metamaterials. He has also investigated measurement and signal processing techniques, most notably microphone array beamforming methods through deconvolution or inverse methods, and the analysis of signals including efficient assessment of data quality and content.