Acoustical scattering by underwater gas-filled cylinders

Nowadays active sonars are used to detect submarines, and usually working on low frequency, while the scattering strength of scatterers made of normal material is too small to match with the scattering strength of submarines in small size. The gas-filled scatterers in small size can form a partial interference environment, which may achieve the purpose of omnibearing interference to low frequency active sonars. In this article, the scattering characters of a gas-filled finite cylinder underwater for all frequencies had been analysed, along with the scattering fields of arbitrary distribute arrays by several cylinder scatterers. The numerical examples of scattering field of single and array gas-filled cylinders are present.