Research on noise reduction technology

This research aims at establishing noise control technology to reduce the noise of a supersonic transport propulsion system down to ICAO Annex 16 Volume I Chapter 3 - 3 dB level. Research on jet noise reduction and fan noise reduction were conducted. A mixer-ejector nozzle was developed for jet noise reduction and a sweep and lean stator was developed for fan noise reduction by the use of advanced CFD analysis. Through the series of model tests in the anechoic chamber and outdoor static engine testing, the achievement of jet noise reduction by the mixer-ejector and fan noise reduction by the sweep and lean stator vane were demonstrated.