Quiet Supersonic Jet Engine Performance Tradeoff Analysis Using a Response Surface Methodology Approach 2002-01-2929

Recent market studies indicate a renewed interest for a quiet Supersonic Business Jet (SBJ). The success of such a program will be strongly dependent upon the achievement of stringent engine noise, emissions and fuel consumption goals. This paper demonstrates the use of advanced design methods to develop a parametric design space exploration environment which will be ultimately used for the identification of an engine concept capable of satisfying acoustic levels imposed by FAR part 36 (stage IV) and NO_x and CO₂ standards as stated in the 1996 ICAO. The engine performance is modeled through the use of Response Surface and Design of Experiments Techniques, enabling the designer/decision-maker to change initial engine parameter values to detect the effects of the responses in a time efficient manner. Engine performance and engine weight results are obtained through physics-based engine analysis codes developed by NASA. An SBJ airframe baseline model is used in conjunction with the engine performance data and executed through a synthesis and sizing code to simulate a supersonic mission. This paper focuses on the tradeoffs associated with noise, emissions and specific fuel consumption of the supersonic engine by employing design parameters such as overall pressure ratio, fan pressure ratio, turbine inlet temperature and throttle ratio. Finally, an optimal engine combination is created to satisfy all the constraints imposed by the aforementioned regulations for a particular mission configuration. Using a statistical analysis package, the designer has the ability to analyze tradeoffs that allows adjustments to be made to certain parameters that, although may compromise others, will still allow the system to fall within engine regulatory limits.