수중 구조물의 음향반사모델

Abstract

This paper suggests a method for implementing an acoustic reflection model through experimental and simulation analysis of an underwater structure for the basis of stealth technology using an acoustic boundary element method (ABEM) that can effectively save time. The ABEM, which supplements for the drawback of finite element analysis (FEM), which takes a lot of computation time when the target is larger than the wavelength, is a numerical analysis method that calculates sound pressure at any point in the sound field from the boundary conditions of the shaped sound field interface. This method was applied to a reflection signal calculation algorithm for simulation analysis. The Rayleigh-Sommerfeld integral equation was applied to calculate the reflective signal returned from a specific reflector. As a result, the reflected signal for each receiving angle in the time domain was obtained, the maximum value of each reflected signal was extracted, converted to a dB scale, and marked on the polar coordinate system to implement the omnidirectional reflective sound pattern of the two models. To verify the validity of the simulation analysis result, an underwater reflection experiment was conducted through the experimental configuration of two transducers for Tx/Rx and the same parameter as the simulation analysis. The reflected signal was obtained in the same process as the previous simulation analysis, and the omnidirectional reflective sound pattern of two models was implemented. By comparing the reflective sound pattern of the experimental result and the simulation analysis result, it was shown that the acoustic reflection model showed a similar tendency, and the effectiveness of the acoustic reflection model was verified. The acoustic reflection model constructed in this paper can be used as basic data for three-dimensional omnidirectional acoustic reflection attenuation in the future.