Acoustic radiation optimization of cylinder shell based on design sensitivity analysis

Finite element method (FEM) is used to calculate the vibration of the structure, and boundary element method (BEM) is used to solve the acoustic radiation problem. On this basis, optimization model of cylinder shell structure is presented and calculation formula of acoustic radiation sensitivity analysis of structural vibration is deduced with emphasis. Acoustic radiation power is considered as objective function. Not only acoustic indexes but also structural indexes are considered as constraints, such as average pressure of internal field, structural mass and natural vibration frequency. Thicknesses of the cylinder shell are considered as design variables. The sensitivities of acoustic radiation power and average pressure of internal field with respect to shell thickness variables are validated compared with finite difference sensitivities. Numerical results show that the reduction of acoustic radiation power can be achieved by optimizing the distributions of shell thicknesses.