Research in the fundamental aspects of aeroacoustics is a key component related to reduction of jet noise, among other technology goals. In the anechoic chamber facility, both single and coaxial flows are studied to provide realistic results for gas turbine engine exhaust acoustics. The studies performed have included investigations into the role of various physical mechanisms on flow sound radiation, including instability waves and reconstruction of jet modes using LSE. Practical evaluation and innovation in propulsion system

exhaust noise is an equally important research activity. Through prior experience and industry partnerships, the development and testing of both passive and active noise reduction schemes has produced results that have advanced the current capabilities in noise reduction. As a complement to understanding the effect of complex geometry and associated flows on radiated acoustics, LES CFD along with CAA is employed to more fully characterize the acoustic sources and predict the acoustic performance of new noise reduction concepts.