A major innovative thrust in urban air mobility (UAM) is underway that could potentially transform how we travel by providing on-demand, affordable, quiet, and fast passenger-carrying operations in metropolitan areas using novel air vehicles, most employing some form of Distributed Electric Propulsion (DEP). The need to support the rapid maturation of technology for UAM is a key motivation for the current NASA UAM Grand Challenge. As noted by NASA, “the Grand Challenge aims to improve UAM safety and accelerate scalability through integrated demonstrations by hosting a series of UAM ecosystem-wide challenges beginning in 2020” addressing a wide range of technical impediments to the growth of UAM, including, notably, the need to characterize vehicle noise levels. The proposed effort will both build on recent major advances in noise modeling at CDI and, in the long term, support of the acoustics analysis goals of the Grand Challenge by enhancing state-of-the-art rotary-wing aeromechanics and acoustics analysis with key additional modeling capabilities needed for comprehensive prediction of DEP aircraft noise, focusing initially on the special problems associated with the prediction of noise from multiple, time-varying RPM systems.
The comprehensive acoustic analysis proposed would enable accurate prediction of acoustics of UAM aircraft in computation times commensurate with daily design work, and would directly support NASA’s ARMD Strategic Thrust #4 (Safe, Quiet, and Affordable Vertical Lift Air Vehicles) in their Technology Roadmap. The developed analysis would be of immediate use to NASA engineers and UAM developers in evaluating and designing low-noise DEP configurations and identifying methods to reduce noise of UAM vehicles.
CDI collaborates with eVTOL UAM vehicle developers who have an immediate need for the proposed analysis to predict aircraft noise during conceptual design. The analysis will also be of great value to the DoD and major rotorcraft manufacturers in analyzing acoustic characteristics of future vertical lift concepts like those under development for the U.S. Army Future Vertical Lift (FVL) program.