Aircraft Noise, Its Source and Reduction

Since the advent of the turbojet engine, there has been much research by aircraft and engine manufacturers into the source of aircraft noise and its reduction.

A review of this research is presented delineating the transition from turbojet engines to turbofan engines to the high by-pass ratio engines being introduced today, and the progress that has been made. Application of the current state-of-the-art to existing airplanes through engine replacement, nacelle retrofit, and flight procedures are also discussed.