As part of Strategic Thrust 3: Ultra-Efficient Commercial Vehicles, in the Strategic Implementation Plan issued by the Aeronautics Research Mission Directorate (ARMD), NASA establishes noise improvement margins (relative to the FAA Stage 4 noise limit) of −32 dB, −42 dB, and −52 dB, for N+1, N+2, and N+3 future aircraft technology generations, respectively. The plan also calls for "tools and technologies to reduce turbofan-thrust-specific fuel consumption, propulsion noise, and emissions." By improving the quality and efficiency of acoustic measurements taken in wind tunnels, the proposed measurement and modeling technology will provide NASA with new capabilities to lead the development of next-generation propulsion systems, airframes, and efficiency technologies. Multiple NASA research centers operate wind tunnels that support aeronautical acoustics research, including the Unitary Plan Wind Tunnels at NASA Ames, the 14' x 22' subsonic tunnel at NASA LaRC, and the 9' x 15' LSWT and five others at NASA GRC.
Community noise exposure continues to be a significant issue near airports, confining growth and impacting quality of life and health of those affected. To counteract growing exposure, ever more stringent noise standards are expected to be implemented by regulatory agencies in the certification of aircraft. These standards are predicated on the discovery of new technologies aimed at reducing aircraft and engine noise. Further noise performance improvements will likely be asymptotic, with incremental improvements resulting in only modest noise reduction. Thus, innovative measurement technologies to better identify and diagnose noise sources within the aircraft and engine are necessary, particularly for the subscale-size test articles and low-SNR environments of wind tunnel testing. ATA believes there is a significant market opportunity for the enhanced CS toolset through adoption at engine manufacturers, airframers, and international aviation authorities. Beyond aviation, CS tools and methods will be applicable to wind turbine, automotive, and industrial noise.