Accession Number : AD0775039

Title :   On Aeroacoustic Coupling in Free-Stream Turbulence Manipulators,

Corporate Author : ILLINOIS INST OF TECH CHICAGO DEPT OF MECHANICS MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : Way,J. L. ; Nagib,H. M. ; Tan-atichat,J.

Report Date : OCT 1973

Pagination or Media Count : 14

Abstract : Wakes of inserts, such as honeycombs, perforated plates and screens, in duct flows often couple non-linearly with acoustic fields leading to objectionable sound levels and modification of the free-stream turbulence. It is experimentally demonstrated how the key mechanism, the shear-layer instabilities in the wakes of these turbulence manipulators, can be driven by artificial sound and how it can be spontaneously organized and intensified in the presence of local acoustic resonances. Tuning of the acoustic excitation can suppress or enhance the downstream turbulence. (Author)

Descriptors :   *Ducts, *Aerodynamics, Acoustics, Turbulence, Coupling(Interaction), Suppression, Wind tunnels

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE