Jet noise is one of the oldest complaints in commercial aviation, and predicting it has long been a mix of physics, measurement and trial. Research teams at Glenn are developing both the theory and the software needed to estimate the sound from aircraft engines, and the tools are meant to help engineers design and analyze new propulsion systems, the center said on its acoustics page. Copies of the programs can be requested through NASA's Software Catalog, according to the page.
The work rests on decades of noise research at the Cleveland center. Glenn has studied engine noise since the first jet airliners appeared in the 1950s, and federal noise limits in the 1970s set off a long search for quieter designs, a NASA history published in March 2025 recounts. Flight tests on a Learjet near Phoenix in 2001 confirmed the noise reduction seen in Glenn's Aero-Acoustic Propulsion Laboratory, and chevrons later appeared on engines powering regional jets and widebody airliners, the history notes.
The distribution route is NASA's broader technology transfer effort. The agency's open Software Catalog, the only repository of its kind in the federal government, bundles codes for aircraft design, mission planning and propulsion analysis, with some programs restricted to U.S. citizens or government use, NASA said when it released the latest edition in July 2025. For acoustics, that means the same models used to shape quieter nozzles can now be run by engine makers, universities and startups outside the agency.