Research and modeling of the bistatic acoustic scattering characteristics of novel multi-faceted conning tower

The overall acoustic echo of a submarine is greatly dependent on the conning tower. For enhancing the acoustic stealth performance of a submarine, it is necessary to research an innovative design scheme of the conning tower to reduce its bistatic target strength (TS). The aim of this work is to reduce the bistatic TS of a conning tower by varying its geometry and streamlining. The accuracy in modeling the acoustic scattering of a conning tower using the Kirchhoff approximation (KA) was validated, compared with finite element analysis. Several angular conning tower geometries were designed to analyze the effect of streamlining and the number of lateral facets on TS using the KA method. In consideration of the actual situation, the acoustic effect of backing medium was analyzed by comparing water-filled elastic hulls with rigid hulls. From the observed TS calculation results, it is shown that the non-streamlined four lateral-facet conning tower geometries are optimal for acoustic stealth performance during the range of receiving angles from -30 degrees to 30 degrees. Furthermore, elastic hulls and rigid hulls provide similar spatial distribution regularities in bistatic configuration with the rigidity affecting the magnitude of the TS.