High-speed propeller noise predictions - Effects of boundary conditions used in blade loading calculationsThe acoustics of an advanced single rotation SR-3 propeller at cruise conditions are studied employing a time-domain approach. The study evaluates the acoustic significance of the differences in blade pressures computed using nonreflecting rather than hard wall boundary conditions in the three-dimensional Euler code solution. The directivities of the harmonics of the blade passing frequency tone and the effects of chordwise loading on tone directivity are examined. The results show that the maximum difference in the computed sound pressure levels due to the use of blade pressure distributions obtained with the nonreflecting rather than the hard wall boundary conditions is about 1.5 dB. The blade passing frequency tone directivity obtained in the present study shows good agreement with jetstar flight data.
Document ID
19870037704
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Nallasamy, M. (NASA Lewis Research Center; Sverdrup Technology, Inc. Cleveland, OH, United States)
Clark, B. J. (NASA Lewis Research Center Cleveland, OH, United States)
Groeneweg, J. F. (NASA Lewis Research Center Cleveland, OH, United States)