The general effort involves in-depth investigation into the fundamental mechanism of turbine engine noise generation and will heavily depend on the results of current Department of Transportation and National Aeronautics as well as Space Administration engine noise reduction programs (Prasad & Atassi, 2009). The first effort in this series is focused toward afterburning supersonic jet exhaust system that has an operating condition typically of supersonic transport (SST) and long-range strategic aircraft propulsion system.
The supersonic jet exhaust noise effort entails three programs directed tow developing the technology to significantly reduce supersonic aircraft population system noise with minimum associated weight penalties and performance. The main objective of the initial programs is for investigating mathematical models to describe the aerodynamic, acoustic and performance features of supersonic jet accurately, in determining critical noise generation mechanism for the strategic aircraft system, and to demonstrate experimentally the advanced instrumentation necessary in verifying the analytical models being observed.
Based on the results, a follow-on effort will be started with a particular objective: The development if an in-depth objective quantitative and a qualitative understanding of the jet noise process which includes the interrelationship of distribution, spectra of acoustic power, level and the spectra as well as directivity of near and far-field radiated sound with the turbulent structure, nozzle performance parameters, and local flow properties. The main objective of the program is evaluating a unique quiet propulsion concept for advanced quiet aircraft system.
References
Prasad, A., & Atassi, O. V. (2009). U.S. Patent No. 7,509,207. Washington, DC: U.S. Patent and Trademark Office.
