Accession Number:

ADA175475

Title:

Nonlinear Acoustics: Long Range Underwater Propagation, Noncollinear Interaction, Reflection and Refraction, and Subharmonic Generation.

Descriptive Note:

Annual summary rept. no. 2, 1 Nov 85-31 Oct 86,

Corporate Author:

TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS

Personal Author(s):

Report Date:

1986-12-05

Pagination or Media Count:

37.0

Abstract:

1 Nonlinear effects in underwater propagation. Two analytical-computational projects in this area are a long range propagation of finite-amplitude pulses in a stratified, dissipative ocean, and b the pressure, temperature, and salinity dependence of the nonlinearity coefficient beta and related quantities. 2 Nonlinear, noncollinear interaction of sound waves. Two analytical and experimental studies of interaction in a rectangular waveguide are described. First, a monochromatic wave is generated in the 1,0 model of the waveguide, and distortion produces a second harmonic component in the 2,0 mode, a third harmonic component in the 3,0 mode, etc. Second, two primary waves are generated, a low frequency wave in the 0,0 mode and a high frequency wave in the 1,0 mode. Of main interest are the sum and difference frequency waves produced by the nonlinear interaction of the two primaries. In a third study, which is not limited to waveguides, the angular dependence of the nonlinearity coefficient beta was investigated. 3 Reflection and refraction of finite-amplitude sound at a plane interface between two fluids. The purpose of this work is to determine two fluids. The purpose of this work is to determine the applicability of Snells law, the law of specular reflection, and other familiar small-signal results when the incident wave is of finite amplitude. 4 Investigation of subharmonic generation and chaos in an acoustical resonance tube.

Subject Categories:

  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE