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Jet Noise Modeling and Measurements to Support Reduced LTO Noise of Supersonic Aircraft Technology Development

Project Number: 059
Category: Aircraft Technology Innovation, Noise, Supersonics

The goal of this project is to develop improved jet noise prediction methods to enable the design of quieter supersonic transport engines.  Project 059 researchers will collaborate closely together, with an advisory team of aircraft engine/airframe industry partners, NASA, the Department of Defense, as well as other related ASCENT research teams. Gas turbine engines for supersonic aircraft need to have a relatively small engine diameter to minimize drag and thus avoid high fuel consumption rates while cruising at supersonic speeds.  Consequently, to also have sufficient thrust during landing and take-off (LTO) conditions, the jet exit velocity needs to be higher than the jet exit velocity of engines typically designed for subsonic aircraft. This increase in exit velocity, by design, results in a substantial increase in LTO noise for supersonic flight capable jet engines. Research is needed to reduce the uncertainty in predicting jet noise from realistic engine designs such that engine makers can make informed design choices that reduce LTO noise. This research aims to develop an open jet engine model that can be evaluated by the analytical methods research teams. The several teams will conduct computational aero-acoustic analyses using a spectrum of different methodologies. One study will be coupled with engine performance models to enable the impact of selected engine operating conditions and geometries on engine performance to be assessed.  An experimental test team will take measurements in an echo-free facility to enable the validation for a range of configurations and simulated jet flows. This work will be closely coordinated with NASA’s engine design efforts.  This project is also in coordination with ASCENT Projects 10 (Georgia Institute of Technology) and 47 (Massachusetts Institute of Technology) that are researching related civil supersonic transport and engine design studies.

Outcomes

For civil supersonic aircraft jet engines, an outcome will be three different levels of computational fidelity of software tools that enable reliable LTO jet noise reduction estimates, based on verified physics-based models validated against measured experimental data, to support design processes used by engine and airframe manufacturers. By treating the engine as a complete system, the predictions will enable a balance to be achieved between reduced LTO noise and capable supersonic performance.

Last updated 7/20/2020

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