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Prediction of high-speed rotor noise with a Kirchhoff formulaA new methodology has been developed to predict the impulsive noise generated by a transonic rotor blade. The formulation uses a full-potential finite-difference method to obtain the pressure field close to the blade. A Kirchhoff integral formulation is then used to extend these finite-difference results into the far-field. This Kirchhoff formula is written in a blade-fixed coordinate system. It requires initial data across a plane at the sonic radius. This data is provided by the finite-difference solution. Acoustic pressure predictions show excellent agreement with hover experimental data for two hover cases of 0.88 and 0.90 tip Mach number, the latter of which has delocalized transonic flow. These results represent the first successful prediction technique for peak pressure amplitudes using a computational code.
Document ID
19880030074
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Purcell, Timothy W.
(NASA Ames Research Center Moffett Field, CA, United States)
Strawn, Roger C.
(NASA Ames Research Center Moffett Field, CA, United States)
Yu, Yung H.
(NASA Ames Research Center; U.S. Army, Aeroflightdynamics Directorate, Moffett Field CA, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Acoustics
Meeting Information
Meeting: National Specialists'' Meeting on Aerodynamics and Aeroacoustics
Location: Arlington, TX
Country: United States
Start Date: February 25, 1987
End Date: February 27, 1987
Sponsors: AHS
Accession Number
88A17301
Distribution Limits
Public
Copyright
Other

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