用物理声学方法计算非硬表面的声散射

本文将物理声学方法(Kirchhoff 近似)推广到非硬表面的情况,以解决带有吸声覆盖层的目标的目标强度计算问题。采用局部平面波近似,散射体表面的声压及其法向导数可以用平面波反射系数和表面声阻抗联系起来,所导出的修正的Kirchhoff近似包含有平面波反射系数。对于阻抗表面球,物理声学方法和严格解的比较表明,物理声学方法仍然是高K_a值时的一种很好的近似方法。

Calculation of acoustic scattering of a nonrigid surface using physical acoustic method

In this paper the physical acoustic method (the Kirchhoff's approximation) is extended to treat the scattering of a nonrigid surface in order to estimate the target strength of tar-gets with absorbing coatings. Using the local plane wave approximation, the relationship between the sound pressure and its normal derivative on the surface can be represented by the reflection coefficient of the plane wave and the acoustic imp dance of the surface. The resulting modified Kirchhoff's approximation involves the plane wave reflection coefficient. For the impedance sphere, a comparison between the physical acoustic method and the exact solution shows that the physical acoustic method is still a good approximation for the higher ka values.