Full-Scale eVTOL Cabin Noise Measurements and Analysis

To create a viable market for full-scale electric Vertical Takeoff and Landing (eVTOL) aircraft, the Urban Air Mobility (UAM) industry must design a comfortable cabin noise environment for passengers. Although the cabin noise environment in eVTOL aircraft may share some similarities with conventional aircraft, helicopters, and automobiles, multirotor eVTOL aircraft have unique design features and operating states that differentiate them from existing vehicles. Cabin noise is a multidisciplinary acoustics, aerodynamics, propulsion, and structures problem, with noise sources generated by interactions between the airframe, rotors, and turbulence. NASA has identified a need for flight test data to validate multidisciplinary models of full-scale, multirotor eVTOL aircraft. Blue Ridge Research and Consulting (BRRC) and The Pennsylvania State University propose to deliver full-scale eVTOL cabin noise measurements and analysis to NASA. With our industry partner, Archer Aviation, our team will acquire full-scale flight test measurements during Phase I of interior and exterior noise and vibration onboard Midnight, Archer’s four-passenger, multirotor eVTOL aircraft. We will develop analytical methods to quantify the vibroacoustic excitation and identify the dominant sources of cabin noise generated by the rotors, electric engines, and fluid-structure interactions onboard Midnight. Based on the results of our initial Phase I measurements, our team will develop a flight test plan to acquire more extensive cabin noise measurements during Phase II. At the end of Phase I, we will deliver the initial flight test data archive, the Phase II flight test plan, and a final technical report to NASA documenting the initial cabin noise measurements and the dominant sources of cabin noise onboard Midnight. The proposed full-scale eVTOL cabin noise measurements and analysis meet NASA’s need for validation data to accelerate the development timeline of full-scale eVTOL aircraft.