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Experimental evaluation of a spinning-mode acoustic-treatment design concept for aircraft inlets. [suppression of YF-102 engine fan noise
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An aircraft-inlet noise suppressor method based on mode cutoff ratio was qualitatively checked by testing a series of liners on a YF-102 turbofan engine as mentioned in this paper.Abstract:
An aircraft-inlet noise suppressor method based on mode cutoff ratio was qualitatively checked by testing a series of liners on a YF-102 turbofan engine. Far-field directivity of the blade passing frequency was used extensively to evaluate the results. The trends and observations of the test data lend much qualitative support to the design method. The best of the BPF liners attained a suppression at design frequency of 19 dB per unit length-diameter ratio. The best multiple-pure-tone linear attained a remarkable suppression of 65.6 bB per unit length-diameter ratio.read more
Citations
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Proceedings ArticleDOI
An experimental study of the acoustic impedance of Helmholtz resonator arrays under a turbulent boundary layer
Jacob Kooi,S.L. Sarin +1 more
TL;DR: In this article, the effect of flow on the acoustic impedance of locally reacting perforate plate liners was investigated. But, it was found that for conditions prevailing in aero-engine ducts the flow effect on impedance does not correlate with the duct main flow Mach number.
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A review of bias flow liners for acoustic damping in gas turbine combustors
Claus Lahiri,Friedrich Bake +1 more
TL;DR: In this article, the authors provide a comprehensive review of bias flow liners and modeling approaches with an extensive study of the most relevant parameters determining the acoustic behavior of these liners.
Assessment of NASA's Aircraft Noise Prediction Capability
TL;DR: In this paper, the authors provide an assessment of the current state of the art for aircraft noise prediction by carefully analyzing the results from prediction tools and from the experimental databases to determine errors and uncertainties and compare results to validate the predictions.
References
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Journal ArticleDOI
A theoretical study of the acoustic impedance of orifices in the presence of a steady grazing flow
TL;DR: In this paper, an analysis of the oscillatory fluid flow in the vicinity of a circular orifice with a steady grazing flow is presented, which is similar to that of Hersh and Rogers but with the addition of the grazing flow.
Proceedings ArticleDOI
Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of single and clustered orifices
TL;DR: In this article, a semi-empirical fluid mechanical model is presented which predicts impedance of a Helmholtz resonator consisting of a single cavity-backed orifice as a function of grazing flow speed, boundary-layer thickness, incident sound amplitude and frequency, and resonator geometry.
Journal ArticleDOI
Self-induced sound generation by flow over perforated duct liners
C.Y. Tsui,Gary A. Flandro +1 more
TL;DR: In this article, an adverse "singing" phenomenon due to flow over perforated liners in a duct was studied experimentally, where the inner skin in contact with the flow had holes (perforations) with pitch distances either equal to or different from those of the honeycomb structures, forming, respectively, narrow-band or broadband liners.
Journal ArticleDOI
Model for the Acoustic Impedance of a Perforated Plate Liner with Multiple Frequency Excitation
TL;DR: In this paper, a quasi-steady nonlinear resistance term was added to the differential equations to account for the effects of orifice velocity and displacement as well as grazing flow.
Journal ArticleDOI
Spinning mode sound propagation in ducts with acoustic treatment
TL;DR: In this article, a theoretical study of the acoustic propagation of spinning modes in acoustically treated open circular ducts was presented, and a suppressor with splitter rings was modeled by using the rectangular approximation to the annular duct.
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