Marston Philip L
Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA.
J Acoust Soc Am. 2009 Jun;125(6):3539-47. doi: 10.1121/1.3119625.
The partial-wave series for the scattering of an acoustic helicoidal Bessel beam by a sphere centered on the axis of the beam is applied to the calculation of the acoustic radiation force by the beam on the sphere in an inviscid fluid. The term "helicoidal" refers to a type of beam having an axial amplitude null and an azimuthal phase gradient. Such a beam is known as an acoustic vortex and only the case of a vortex having a unit magnitude topological charge is considered. There is no monopole contribution to the radiation force. Radiation force examples are computed for a soft sphere, a fixed rigid sphere, a movable rigid sphere, an aluminum sphere in water, and an acrylic sphere in water. Beam parameters are found for the rigid sphere and the aluminum and acrylic cases in which the radiation force is directed opposite the propagation direction of the beam. Negative radiation forces appear to be associated with relatively weak scattering into the backward hemisphere. Some aspects of the low frequency scattering of plane waves and helicoidal Bessel beams are examined for movable rigid spheres.
将以声螺旋贝塞尔光束轴为中心的球体对声螺旋贝塞尔光束的散射的分波级数应用于计算无粘流体中该光束对球体的声辐射力。术语“螺旋的”指的是一种具有轴向振幅零值和方位相位梯度的光束。这样的光束被称为声涡旋，并且仅考虑具有单位大小拓扑电荷的涡旋情况。辐射力没有单极子贡献。计算了软球、固定刚性球、可移动刚性球、水中铝球和水中丙烯酸球的辐射力示例。针对刚性球以及辐射力与光束传播方向相反的铝球和丙烯酸球情况，找到了光束参数。负辐射力似乎与向后半球的相对较弱散射有关。研究了可移动刚性球的平面波和螺旋贝塞尔光束的低频散射的一些方面。
