A Numerical Study On The Acoustic Reflections From A Submerged Piezoelectric/Elastic Bilaminar Spherical Shell

The acoustic reflection from a submerged piezoelectric/elastic bilaminar spherical shell is studied by the finite element method (FEM). It is supposed to diminish the reflection from the spherical shell by applying an appropriate controlled voltage potential across the piezoelectric shell which was known as an active acoustic control method.It is used the multiphysics module of the software ANSYS to establish the finite element model which combines elastic, piezoelectric, and fluid-loading effect. In this model the sphere is enclosed by infinite fluid and an acoustic point is fitted in the fluid. First calculate the reflection when the piezoelectric shell is short-circuit, we get the scatter pressure on each node. Then find the required electric potential to eliminate the scatter pressure on each node and study them. According to the studying, an appropriate voltage potential was selected and be loaded on. By calculating we get the reflection after controlled. Finally a comparison is made to find the efficiency in noise reduction. The numerical results show that applying an appropriate voltage potential across the piezoelectric shell can suppressing the far-field reflected pressure on the direction of the line linked the sphere core and the acoustic point. And the reflected pressure in a cone fluid field was reduced simultaneously. For any direction, an appropriate voltage can be found to suppress the far-field reflected pressure on it.