23rd Congress of International Council of the Aeronautical Sciences, 8-13 September, 2002, Toronto, Canada
Paper ICAS 2002-8.4.3

OPTIMIZATION OF ACOUSTIC LINER DESIGN FOR AXISYMMETRIC MIXER-EJECTOR NOZZLES UNDER ESPR PROGRAM

M. Salikuddin
GE Aircraft Engines, USA

Keywords: mixer-ejector nozzles, espr, acoustic optimization

The Environmentally Compatible Propulsion System for Next Generation Supersonic Transport Research and Development Program (ESPR) is aimed at developing and demonstrating a turbofan engine for a supersonic aircraft application. This includes the development of an energy efficient exhaust system with an axisymmetric mixer-ejector for noise reduction. Noise sources generated by a mixer-ejector nozzle include internal noise generated inside the mixer-ejector and pre-merged and merged noise generated outside the ejector. The noise generated inside the ejector has significant high frequency content. The acoustic liner is therefore an essential element for the ejector to suppress the high frequency internal noise. A design process is developed and used to optimize the liner design to maximize the internal noise suppression. A polynomial equation to predict effective perceived noise level (EPNL) as a function of liner design parameters is developed for parametric and trade studies. This paper includes detail farfield noise prediction process, liner optimization methods, and relevant results.

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