Influence of amplitude on propagation distortion of finite amplitude acoustic wave
1. School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China; 2. School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150080, China; 3. School of Mea-surement-Control Technology and Communications Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150080, China
Abstract:To confirm the characteristic of nonlinear propagation, the propagation distortion of single-frequency and double-frequency acoustic wave was investigated by theories and experiments. According to the propagation equation of single acoustic wave by Riemann Earnshaw and Bessel-Fubini, the simulation harmonic curves were got in the process of nonlinear propagation, and the threshold relationship between nonlinear effect and amplitude of single-frequency acoustic wave was observed based on experiments. Based on the mathematical analytic formula of nonlinear cumulative velocity of acoustic wave and gradient of acoustic waves at discontinuity point after nonlinear interaction of two acoustic waves by Burgers equation, the relation curve of nonlinear cumulative velocity of acoustic wave, transitive gradient and amplitude ratio of acoustic wave were simulated. The results show that when acoustic wave propagates with nonlinear effect in medium, the characteristic of nonlinear propagation has cumulative effect. When the initial phase difference is 0 or π, the nonlinear interaction is gradually decreased or increased among nonlinear cumulative velocity of acoustic wave, transitive gradient and amplitude ratio of acoustic wave. When the amplitude ratio is increased to a certain value, the nonlinear cumulative velocity of acoustic wave and the transitive gradient both tend to a constant value.