Nonlinear Acoustics: Reflection and Refraction, Propagation in a Periodic Waveguide, Scattering of Sound by Sound, and Ellipsoidal Focusing
Abstract
Reflection and refraction of plane finite-amplitude waves at a plane interface between two fluids. The nonlinear equation for three-dimensional waves in a thermoviscous, relaxing fluid was derived. A second-order perturbation solution was obtained for the reflection-refraction problem for the case of a lossless fluid and an arbitrary source signal. Propagation in a periodic waveguide. Propagation has been measured in a plane wave tube loaded periodically with reactive branch elements. Experiments with small-signal waves verify in fine detail the dispersion relation that had been derived earlier (and this year modified to include thermoviscous boundary layer effects and the end correction for the branch elements). Scattering of sound by sound. Primary work had been on the role of source and boundary conditions. Experiments on single- beam and crossed-beams in the megahertz range is in progress. Ellipsoidal focusing. This work, which has applications to lithotripsy, is thus far mainly experimental. The experiments are carried out in air. An electric spark located at the near focus of an ellipsoidal reflector generates an N wave. The reflector concentrates the sound at the remote focus.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1989
- Accession Number
- ADA211412
Entities
People
- David T. Blackstock
Organizations
- University of Texas at Austin