Acoustic Propagation in Turbulent Layers

Abstract

The objective of this work was to determine the extent to which acoustic propagation varies in the vicinity of topographic features where the flow oscillates between laminar and turbulent states. Since these topographic features are ubiquitous in coastal areas, the results will impact ACOMMS performance in these areas. In a recent experiment by Moum and Nash, oceanographic measurements were made around a small bank off the western continental shelf. Temperature, salinity, and turbulent dissipation rate measurements were obtained from this experiment and broadband (9-11kHz) acoustic simulations done to determine the impact of the turbulent sound speed field on acoustic propagation. Acoustic simulations show an overall increase in transmission loss of about 10-15dB within the 10-11KHz band. This corresponds to the times where intense turbulence occurs. The transmission loss correlates well with the turbulent dissipation rate.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2007
Accession Number
ADA516912

Entities

People

  • Ewa Jarosz
  • James N. Moum
  • R. L. Field

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Signals
  • Boundary Layer
  • Dissipation
  • Energy
  • Flow
  • Frequency
  • Geographic Regions
  • Layers
  • Losses
  • Measurement
  • Military Research
  • Power Spectra
  • Transmission Loss
  • Triangles
  • Turbulent Flow
  • Waveforms

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Fluid Dynamics.
  • Oceanography.