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Jet Mixing Noise Scaling Laws SHJAR Data Vs. PredictionsHigh quality jet noise spectral data measured at the anechoic dome at the NASA Glenn Research Center is used to examine a number of jet noise scaling laws. Configurations considered in the present study consist of convergent as well as convergent-divergent axisymmetric nozzles. The spectral measurements are shown in narrow band and cover 8193 equally spaced points in a typical Strouhal number range of (0.01 10.0). Measurements are reported as lossless (i.e. atmospheric attenuation is added to as-measured data), and at 24 equally spaced angles (50deg to 165deg) on a 100-diameter arc. Following the work of Viswanathan [Ref. 1], velocity power laws are derived using a least square fit on spectral power density as a function of jet temperature and observer angle. The goodness of the fit is studied at each angle, and alternative relationships are proposed to improve the spectral collapse when certain conditions are met. On the application side, power laws are extremely useful in identifying components from various noise generation mechanisms. From this analysis, jet noise prediction tools can be developed with physics derived from the different spectral components.
Document ID
20080047437
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Khavaran, Abbas (NASA Glenn Research Center Cleveland, OH, United States)
Bridges, James (NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 24, 2013
Publication Date
September 23, 2008
Subject Category
Acoustics
Report/Patent Number
E-16731
Meeting Information
Meeting: Acoustic Technical Working Group
Location: Williamsburg, VA
Country: United States
Start Date: September 23, 2008
End Date: September 24, 2008
Funding Number(s)
WBS: WBS 561581.02.08.03.18.03
Distribution Limits
Public
Copyright
Public Use Permitted.

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