Analysis on the vibration and sound radiation characteristics of double cylindrical shells using wave number spectrums

In order to explain the universal rules between the vibrational model and the sound radiation of double cylindrical shells, the coupling vibration responses of the structure are obtained with Finite Element Method combined with Boundary Element Method (FEM/ BEM). Then, the radial vibration on the cylindri-cal coupling surface is transformed into the wave number domain with the wave number analysis spectrum method, which generates the vibration and radiation power spectrums. Next, the vibration and sound radia-tion characteristics are obtained by comparing the vibration power and radiation power associated with each component of regular waves. It is seen that the vibration of outer shell consists of many components in cir-cumference and is dominated by short waves in the axial direction. Meanwhile, the sound radiation is domi-nated by low order vibration components in circumference and long waves in the axial direction.