수중 모래에서 차주파수 음파를 이용한 비선형 음향변수 추정에 관한 연구

Abstract

Difference frequency acoustic wave from nonlinear interaction of two primary acoustic waves at frequencies of 76 and 114 kHz was utilized with a parametricacoustic array theory to estimate the nonlinear acoustic parameter of water-saturated sand. Such nonlinear acoustic parameter can be used as backgroundinformation for the nonlinear acoustic investigation of bottom or sub-bottom profiling in the ocean sands. The nonlinear acoustic parameter β for the water-saturated sand used as a reference in this study was estimated asβ = 80.5 ± 5.1 at the difference frequency of 38 kHz. The estimated nonlinear acoustic parameter of watersaturated sand in this study was also compared and analyzed with those estimated in previously publishedliteratures. It was suggested that the difference frequency wave method used to estimate the nonlinear acoustic parameter of water-saturated sand can be employed as a good method to estimate the nonlinear acoustic parameters of fluid-like granular media.