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Analytical investigation of adaptive control of radiated inlet noise from turbofan enginesAn analytical model has been developed to predict the resulting far field radiation from a turbofan engine inlet. A feedforward control algorithm was simulated to predict the controlled far field radiation from the destructive combination of fan noise and secondary control sources. Numerical results were developed for two system configurations, with the resulting controlled far field radiation patterns showing varying degrees of attenuation and spillover. With one axial station of twelve control sources and error sensors with equal relative angular positions, nearly global attenuation is achieved. Shifting the angular position of one error sensor resulted in an increase of spillover to the extreme sidelines. The complex control inputs for each configuration was investigated to identify the structure of the wave pattern created by the control sources, giving an indication of performance of the system configuration. It is deduced that the locations of the error sensors and the control source configuration are equally critical to the operation of the active noise control system.
Document ID
19950004864
Document Type
Conference Paper
Authors
Risi, John D. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Burdisso, Ricardo A. (Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Inst. of Noise Control Engineering, Noise Con 1994: Proceedings of the 1994 National Conference on Noise Control Engineering. Progress in Noise Control for Industry
Subject Category
ACOUSTICS
Funding Number(s)
CONTRACT_GRANT: NAG1-230
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.