Analysis of sound radiation characteristics of complex double shells

The double stiffened shell connected by annular plates is systematically studied. The shell motion is obtained using the classical Flügge operator, the effects of stiffeners are induced into vibration equation by treating them as reverse forces and moments on the shell, and the fluid field between the inner shell and outer shell is solved by applying Helmholtz equation and the continuity conditions of the displacement on the surface of fluid-structure. At last the vibration equation coupled by the sound-fluid-structure are constituted and solved. The effects of the double shell parameters and linked types between the double shells on the sound radiation are discussed in detail. The following conclusions can be obtained:The smaller the space between the inner shell and outer shell is, the stronger the coupling of the inner shell and outer shell is, the higher the radiated power and radial quadratic velocity is, the more indistinct the shield of the outer shell is. The changes of the thickness of the inner shell and outer shell influenced the radial quadratic velocity greatly, and influenced the radiated power indistinctly. The thicker the thickness is, the lower the radial quadratic velocity is.