Accession Number:

ADA532973

Title:

Sound Speed and Attenuation in Multiphase Media

Descriptive Note:

Annual rept.

Corporate Author:

BOSTON UNIV MA DEPT OF AEROSPACE AND MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

2008-09-20

Pagination or Media Count:

8.0

Abstract:

One research goal developed from conducted shallow water SW acoustic transmission experiments in sandy-silty areas 1 revealed a nonlinear power law frequency-dependent attenuation at lower frequencies less than or equal to 1 kHz consistent with results reviewed in 2-5 and the observations by the ONR-HEP program. The Biot Theory 6 predicts that the sandy- sediment frequency-dependent attenuation should be quadratic, alpha f alpha fo f fo exp n with n 2 however the observed dependence was n 1.8 plusminus 0.2 . Thus the long-range goal was to develop a simplified theory of sediment attenuation 7 verified by measurements that could explain this dependence and be applied to ocean sediments.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Acoustic Detection and Detectors
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE