Jerome Thomas S, Ilinskii Yurii A, Zabolotskaya Evgenia A, Hamilton Mark F
Applied Research Laboratories, The University of Texas at Austin, Austin, Texas 78713-8029, USA.
J Acoust Soc Am. 2019 Jan;145(1):36. doi: 10.1121/1.5084045.
When the density and compressibility of an object are similar to the corresponding properties of the surrounding fluid and the incident sound field is a standing wave, the Born approximation may be used to calculate the acoustic radiation force and torque on an object of arbitrary shape. The approximation consists of integration over the monopole and dipole contributions to the force acting at each point within the region occupied by the object. The method is applied to axisymmetric objects, for which the force and torque may be expressed as a single integral along the axis of symmetry. The integral is evaluated analytically for spheres and cylinders. The accuracy of the Born approximation is assessed by comparison with complete solutions for compressible spheres and prolate spheroids that are based on expansions of the incident, scattered, and transmitted fields in terms of eigenfunctions of the corresponding separable coordinate system. Results are presented for objects with various densities and compressibilities relative to the surrounding fluid, as well as different shapes, sizes, and orientations of the object with respect to the standing wave field. The method also accommodates spatial variations of the density and compressibility within the object.
当物体的密度和可压缩性与周围流体的相应特性相似，且入射声场为驻波时，可使用玻恩近似来计算任意形状物体上的声辐射力和扭矩。该近似包括对作用于物体所占区域内各点的力的单极子和偶极子贡献进行积分。该方法应用于轴对称物体，其力和扭矩可表示为沿对称轴的单一积分。对于球体和圆柱体，该积分可通过解析法求值。通过与基于入射、散射和透射场在相应可分离坐标系本征函数展开的可压缩球体和长椭球体的完整解进行比较，评估玻恩近似的准确性。给出了相对于周围流体具有不同密度和可压缩性的物体，以及物体相对于驻波场的不同形状、尺寸和取向的结果。该方法还考虑了物体内部密度和可压缩性的空间变化。
