Research groups at the NASA Glenn Research Center conduct experiments at a number of world-class advanced facilities. These include the 9 by 15 foot low-speed wind tunnel (9x15 LSWT), the Aeroacoustic Propulsion Laboratory (AAPL), the Small Hot Jet Acoustic Rig (SHJAR), the Nozzle Acoustic Test Rig (NATR), the DGEN AeroPropulsion Research Turbofan Engine (DART), and the Acoustic Test Laboratory (ATL). These facilities allow specialists to study the behavior of aircraft engines, noise characteristics of propulsion systems, and aerodynamic processes under controlled conditions that approximate real flight conditions. The center's equipment is used to develop technologies aimed at reducing aircraft noise and improving engine efficiency, which is significant for both civil and future aviation. The NASA Glenn Research Center, located in Ohio, is one of the agency's key divisions engaged in aerospace research, propulsion system development, and related technologies. Work at such experimental facilities forms the foundation for further engineering and scientific developments in aviation and space exploration.