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

ABSTRACT:The increased sound produced by tactical aircraft has become more problematic with the enhanced performance requirements that are being set forth for the next generation war fighter. Given the complexity of the engine and the flow that it produces, accurate predictions of the full-scale exhaust stream and far-field acoustics are still challenging topics, despite over 60 years of jet noise and jet flow research. In particular, trade-off decisions between thrust and noise over a broad range of engine operating conditions continues to be a challenging task. The problem is exacerbated by the additional complexities of having multi-stream nozzles comprising complex geometries. The proposed research aims to eliminate this void by developing a robust and reliable analysis tool capable of predicting the sound performance from a multi-stream and heated supersonic nozzle. The engineering tool that will be developed in the proposed research will leverage order reduction and data fusion techniques to blend the strengths of both laboratory scale experiments and analytical modeling to provide fast answers for critical decisions to be made in the design room.BENEFIT:A successful completion of the research program will see the integration of an experiment-based predictive methodology with engine cycle assessment tools that will have the capability of providing valuable acoustics and performance related information to the aircraft systems design engineers. This methodology will be jointly marketed by CRAFT Tech and their team to prime contractors in order to study its effectiveness on aircraft configurations of interest to the Air Force, particularly supersonic fighters and attack aircraft. However, the effectiveness of the technology is not restricted to military applications; it can be easily extended to the commercial aircraft industry to generate performance characteristics maps over a wide range of engine operating conditions. As noise requirements for commercial aircraft engines becomes increasingly more stringent leading to the development of new engine technologies to meet these revised standards, the technology developed in this SBIR program, in conjunction with experimental measurements, can be used for the identification of an optimal region of engine operating conditions that provides optimal acoustic performance at minimal thrust and performance penalties. Our team can provide the functional predictive acoustics methodology developed during this program in a suitable configuration so as to couple with a desired engine cycle assessment tool.