A Study of Echo Reduction of Underwater Acoustic Material Considering Ocean Condition

수중환경을 고려한 수중 음향재료의 반향음 감소성능 연구

The requirement of acoustic material which is used in underwater environment more increases. The material is used to reduce acoustic signature and radiate noise for underwater vehicle. Underwater acoustic material was made by viscoelastic material such as a rubber and a polyurethane etc. The mechanical and acoustic characteristics of these material change with hydrostatic pressure. In order to increase an acoustic performance according to hydrostatic pressure, several kinds of scatterers were added to viscoelastic material. In this paper, acoustic modelling and analysis techniques of underwater acoustic material with hydrostatic pressure were introduced and proposed. The specimens for pulse tube test were made and echo reductions were calculated and measured with hydrostatic pressure. Also the characteristics of echo reduction of the specimens with hydrostatic pressure were obtained and discussed.