Satellite photo close-up of the branch offices, AAPL and 9x15 Wind Tunnel. To maintain our leadership position in research and development of technologies for quieter, highly efficient propulsion systems. 2000 Year in Review are covered in more detail . The Acoustics Branch conducts research directed at aircraft engine noise reduction. Experimental and analytical research focuses on noise reduction technologies for turbofan engines while maintaining acceptable aerodynamic performance.
Emphasis is given to fan and jet noise reduction for both subsonic and supersonic applications.
Nozzles are tested in anechoic free-jets for jet noise research. Detailed diagnostic measurements are also obtained using LDV, hot-wires, acoustic mode measurements, kulites, and phased array methods. Analysis Computer codes are developed that model the steady and unsteady aerodynamics for various components of a turbofan engine. Engine noise prediction codes are developed and validated using experimental data. Active noise control methods are explored for both fan and jet noise reduction.