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A new look at sound generation by blade/vortex interactionAs a preliminary attempt to understand the dynamics of blade/vortex interaction, the two-dimensional problem of a rectilinear vortex filament interacting with a Joukowski airfoil is analyzed in both the lifting and nonlifting cases. The vortex velocity components could be obtained analytically and integrated to determine the vortex trajectory. With this information, the aeroacoustic low-frequency Green's function approach could then be employed to calculate the sound produced during the encounter. The results indicate that the vortex path deviates considerably from simple convection due to the presence of the airfoil and that a reasonably sharp sound pulse is radiated during the interaction whose fundamental frequency is critically dependent upon whether the vortex passes above or below the airfoil. Determination of this gross parameter of the interaction is shown to be highly nonlinearly dependent upon airfoil circulation, vortex circulation, and initial position.
Document ID
19850050804
Document Type
Reprint (Version printed in journal)
Authors
Hardin, J. C. (NASA Langley Research Center Hampton, VA, United States)
Mason, J. P. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 12, 2013
Publication Date
April 1, 1985
Publication Information
Publication: ASME, Transactions, Journal of Vibration, Acoustics, Stress, and Reliability in Design
Volume: 107
ISSN: 0739-3717
Subject Category
ACOUSTICS
Report/Patent Number
ASME PAPER 84-WA/NCA-2
Distribution Limits
Public
Copyright
Other