Accession Number:

ADA622149

Title:

Hydrodynamic Noise from Flexible Roughness Elements

Descriptive Note:

Final rept. 1 Mar 2014-31 Mar 2015, Jun 2015

Corporate Author:

LEHIGH UNIV BETHLEHEM PA

Report Date:

2015-06-29

Pagination or Media Count:

15.0

Abstract:

The influence of a poroelastic surface structure composed of elastic fibers, as inspired by the wings of silent owl species, is investigated theoretically through the development of two mathematical models. First, in the spatial limit of a sparse distribution of fibers that are hydrodynamically uncoupled, the influences of fiber bending and a background flow on the far field sound are studied using conformal mapping. A second model reveals how the porous surface structure can suppress pressure fluctuations, which agrees well with companion experiments performed by Dr. William Devenport of Virginia Tech.

Subject Categories:

  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE