Reduced-Order Model for the Prediction of Supersonic Aircraft Jet Noise

ABSTRACT: Supersonic jet noise is a major issue affecting Department of Defense (DoD) flight operations. These issues include the near-field noise, which causes hearing damage specifically for Navy personnel on aircraft carriers. More relevant to Air Force operations, is the far-field or community noise problem. To address these problems, Spectral Energies, LLC proposes to develop a noise prediction tool for supersonic jet nozzles capable of interfacing with a gas turbine engine cycle analysis tool such as Numerical Propulsion System Simulation (NPSS). For Phase I, the noise model will be developed for a single geometry and validated against existing experimental and computational data. In Phase II, the noise prediction tool will evolve to account for different geometries (i.e. aspect ratio and shape) and will also have the ability to be integrated with existing engine cycle tools. The effects of complex phenomena such as swirl, non-linear acoustic propagation, upstream turbulence, etc. could be added to the tool as additional modules. Since this tool will ultimately be used to predict noise for the full-scale aircraft and the cycle analysis provides information about the other engine components, it would be useful to incorporate the noise produced by other engine components as well. This tool can also be used to adjust the nozzle geometry and engine cycle to assess the potential for noise reduction without sacrificing the performance (thrust, fuel efficiency, and survivability). BENEFIT: The commercial products produced as result of this SBIR are the noise prediction tool, flow control methodologies, and measurement instrumentation. The main customers for the noise prediction code are the Air Force and Navy. Other potential costumers are General Electric, Pratt and Whitney, Lockheed Martin, Boeing, and other aircraft/engine companies. This tool may help aircraft companies develop engines that are quiet and have high fuel efficiency by integrating the noise tool into their existing cycle analysis codes. In addition, institutions working on the supersonic commercial transport, such as Gulf Stream, Lockheed Martin, and NASA may be interested in the tools and knowledge developed for this study to help reduce supersonic shock noise.