Shock Propagation and Attenuation in Bubbly Liquids: Modeling Wave Propagation Using a Nonlinear Equation-of-State

Abstract

Bubbly media play a significant role in underwater acoustics, medical ultrasound and in industrial systems where gas-liquid flows are present. The focus of our research has been to develop a continuum model for bubbly mixtures that can be used to model physical phenomena in these areas. The key to the continuum model is a nonlinear, non-equilibrium equation of state (EOS) that relates pressure to the mixture density and the number density (number of bubbles per unit volume) and their first two material time derivatives. The derivation of the EOS is presented here and a number of traveling wave solutions obtained using this nonlinear EOS are discussed. To develop an accurate model, two important damping mechanisms for the medium had to be incorporated: heat transfer and relative motion between the gas and liquid phases. To quantify the importance of heat transfer, an analysis of single-bubble radial oscillations was completed in this work, and a Pade' approximation for the thermal damping was derived from the linearized gas dynamics equations. A second important damping mechanism arises from relative motion between the gas bubbles and the liquid. The quantitative effects of relative motion on the damping of waves in bubbly liquids has also been examined and is described here.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1999
Accession Number
ADA370801

Entities

People

  • Ali Nadim
  • Jerome J. Cartmell
  • Paul E. Barbone

Organizations

  • Boston University

Tags

Communities of Interest

  • Air Platforms
  • Biomedical
  • C4I
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustics
  • Coefficients
  • Differential Equations
  • Equations
  • Gas Dynamics
  • Heat Transfer
  • Ideal Gas Law
  • Liquid Phases
  • Mach Number
  • Oscillation
  • Relative Motion
  • Shock Waves
  • Specific Heat
  • Traveling Waves
  • Wave Propagation
  • Waves

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Control Systems Engineering.
  • Underwater engineering and Marine Technology.