This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Boundary Layer Considerations for Optimization of Acoustic Liners for Aircraft Engine Ducts
Annotation ability available
Sector:
Language:
English
Abstract
This paper presents a study of the effects of shear flow on the sound attenuation in lined ducts. The main emphasis is on proper selection of liner impedance for optimum attenuation performance of the acoustic liner in the presence of realistic duct boundary layer flows. Results are given for arbitrary spinning acoustic propagation modes, and combinations of modes in treated inlet and exhaust ducts for a variety of simple boundary layer velocity profiles and boundary layer thicknesses. It is shown that boundary layer effects are significantly reduced when all the propagating modes are combined to give total attenuation.
Authors
Topic
Citation
Prydz, R., "Boundary Layer Considerations for Optimization of Acoustic Liners for Aircraft Engine Ducts," SAE Technical Paper 760896, 1976, https://doi.org/10.4271/760896.Also In
References
- Wirt L. S. “Analysis, Testing, and Design of Lined Ducts.” Journal of the Acoustical Society of America 51 5 May 1972
- Wirt L. S. “Sound-Absorptive Materials to Meet Special Requirements.” Journal of the Acoustical Society of America 57 1 January 1975
- Feder E. Dean L. W. “Analytical and Experimental Studies for Predicting Noise Attenuation in Acoustically Treated Ducts for Turbofan Engines.” NASA CR-1373 September 1969
- Nayfeh A. H. Kaiser J. E. Telionis D. P. “The Acoustics of Aircraft Engine Duct Systems,” AIAA Paper No. 73-1153 October 1973
- Goodall R. G. Painter G. W. “Conceptual Study of Advanced Acoustic-Composite Nacelles,” NASA CR-132649 May 1975
- Rice E. “Spinning Mode Sound Propagation in Ducts With Acoustic Treatment and Sheared Flow.” AIAA Paper 75-519 March 1975
- Tester B. J. “Some Aspects of Sound Attenuation in Lined Ducts Containing Inviscid Mean Flows With Boundary Layers.” Journal of Sound and Vibration 28 2 May 1973
- Tester B. J. “The Optimization of Modal Sound Attenuation in Ducts, in the Absence of Mean Flow,” Journal of Sound and Vibration 27 4 April 1973
- Nayfeh A. H. Kaiser J. E. Shaker B. S. “Effect of Mean-Velocity Profile Shapes on Sound Transmission Through Two-Dimensional Ducts.” Journal of Sound and Vibration 34 3 June 1974
- Schlichting H. “Boundary Layer Theory.” Kestin J. New York McGraw-Hill Book Company, Inc. Fourth 1960