DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Nonlinear Acoustics: Noncollinear Interaction, Reflection and Refraction, and Scattering of Sound by Sound.
Annual rept. 1 Nov 86-30 Sep 87,
TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
Pagination or Media Count:
Research on four topics in nonlinear acoustics is described. 1. dependence of three coefficients of nonlinearity for sea water on pressure, temperature, and density. Computation of the coefficients from a combination of theoretical and empirical relations is in progress. 2. Nonlinear, noncollinear interaction of sound waves. Three journal articles have been written, two on interaction in a rectangular waveguide and one on coefficient of nonlinearity for collinear and noncollinear interaction. 3. Reflection and refraction of finite amplitude sound at a plane interface between two fluids. A new form of Snells law valid for waves of finite amplitude is derived. An experiment to test the implications of the new law is being carried out. 4. Scattering of sound two crossed sound beams is discussed. An experimental test of recent theoretical treatments is bing prepared. A preliminary experiment is the measurement of the range dependence of finger lobes in the second harmonic radiation produced in the field of a monochromatically driven piston. Keywords nonlinear acoustics coefficient of nonlinearity scattering of sound by sound noncollinear interaction refraction reflection waveguide.
APPROVED FOR PUBLIC RELEASE