Acoustic scattering from a porous sphere

The scattering of a plane acoustic wave from a porous sphere is studied using Biot's theory about the Porous medium.First,by form functions of Porous sphere,under open and sealed-pore boundary conditions the scattering of porous sphere is studied.Second,the scattering Power of porous sphere is deduced theoretically,and the relations of the scattering power and ha are calculated numerically.It is shown that,the form function has a very complicated structure.there exists a significant difference between the form function of open and sealed-pore boundary conditions.Under sealed-pore boundary condition many Peaks and dips appear in the form function.The scattering Power of sealed-pore sphere is also higher than that of open-Pore sphere.