Session A24: Acoustics I

8:00 AM–9:57 AM, Sunday, November 24, 2013
Room: 319

Chair: Daniel Bodony, University of Illinois at Urbana-Champaign

Abstract ID: BAPS.2013.DFD.A24.4

Abstract: A24.00004 : Vortex Noise Reductions from a Flexible Fiber Model of Owl Down

8:39 AM–8:52 AM

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Authors:

  Justin Jaworski
    (Lehigh University)

  Nigel Peake
    (University of Cambridge)

Many species of owl rely on specialized plumage to reduce their self-noise levels and enable hunting in acoustic stealth. In contrast to the leading-edge comb and compliant trailing-edge fringe attributes of owls, the aeroacoustic impact of the fluffy down material on the upper wing surface remains largely speculative as a means to eliminate aerodynamic noise across a broad range of frequencies. The down is presently idealized as a collection of independent and rigid fibers, which emerge perpendicularly from a rigid plane and are allowed to rotate under elastic restraint. Noise generation from an isolated fiber is effected by its interaction with a point vortex, whose motion is induced by the presence of the rigid half-plane and the elastically-restrained fiber. Numerical evaluations of the vortex path and acoustic signature furnish a comparison with known analytical results for stationary fibers, and results from this primitive model seek to address how aerodynamic noise could be mitigated by flexible fibers.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2013.DFD.A24.4