Research On The Characteristics Of Acoustic Backscattering Of Structural Materials

The concealment of underwater vehicles,especially submarines,has always been the focus of the navies of various countries.To reduce the range of enemy sonars,both the reflection of active detection signals from underwater vehicles and the water Disembark the aircraft itself.Laying an acoustic cover on the surface of an underwater vehicle is one of the important means to effectively improve the concealment of the underwater vehicle and ensure the survival rate.Correspondingly,the problems faced by the research of the target characteristics of an underwater vehicle with an acoustic cover have become increasingly complex and diverse.In related research,accurate input of the performance parameters of the acoustic overlay on the surface of the underwater vehicle can accurately predict the radiated noise and target intensity of the underwater vehicle.The target strength prediction based on the current acoustic performance parameters often has a certain gap with the actual situation.In order to improve the effectiveness of such input parameters,this paper proposes the parameter of sound reverse reflection coefficient of structured acoustic materials.Based on the plane wave decomposition theory based on two-dimensional Fourier transform,this paper defines the backscattering coefficient of infinitely large flat structure acoustic materials under plane wave oblique incidence conditions,and uses this as a supplementary parameter to measure the characteristics of structural acoustic materials.Through the finite element software COMSOL,a variety of structural material models are established,and a large number of numerical calculations are performed.After periodic data expansion of the simulated sound field,plane wave decomposition is performed in the wavenumber domain.Acoustic scattering coefficients in all directions can be calculated and backscattering coefficient extracted therefrom.Further calculation and analysis of the sound scattering of structural materials at multiple frequencies and angles of incidence,and comparative analysis of the reverse acoustic performance of structural materials with different materials,different cavity shapes and cavity distributions...