Experimental Study of Sound Waves in Sandy Sediment

Abstract

This dissertation describes experiments intended to help understand the physics of sound (compressional waves) propagating through sandy sediments (unconsolidated porous media). The theory (using a lumped parameter model) and measurements (using a reflection ratio technique) includes derivations and measurements of acoustic impedance, effective densities, wave speeds (phase velocities), effective pressures, mode shapes, pressure reflection coefficients, and material moduli. The results show the acoustic impedance divided by the phase velocity, rendering an "effective density," is less than the total density of the sediment (effective density 89% plus or minus 3% of total). The results also show the fluid in the sediment oscillates back-and-forth 2.2 plus or minus 0.4 times farther than the sand in the sediment (mode shape) during the passing of a sound wave. These facts suggest the existence of Biot waves (two compressional waves) in water- saturated sand.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 2003
Accession Number
ADA422568

Entities

People

  • Michael W. Yargus

Organizations

  • University of Washington

Tags

Communities of Interest

  • Advanced Electronics
  • Ground and Sea Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustic Impedance
  • Acoustic Measurement
  • Acoustic Propagation
  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Differential Equations
  • Doppler Effect
  • Electrical Engineering
  • Equations Of Motion
  • Materials
  • Materials Science
  • Phase Velocity
  • Physics Laboratories
  • Porous Materials
  • Sound Waves
  • Wave Propagation

Readers

  • Acoustical Oceanography.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Mathematics or Statistics