In this article, the acoustic radiation force and torque exerted on a small spheroidal particle immersed in a nonviscous fluid inside an ideal cylindrical chamber is theoretically investigated. The ideal chamber comprises a hard top and bottom (rigid boundary condition) and a soft or hard lateral wall. By assuming that the particle is much smaller than the acoustic wavelength, analytical expressions of the radiation force and torque caused by an acoustic wave of arbitrary shape are presented. Unlike previous results, these expressions are given relative to a fixed laboratory frame. The model is showcased for analyzing the behavior of an elongated metallic microspheroid (with a $10:1$ aspect ratio) in a half-wavelength acoustofluidic chamber with a diameter of a few millimeters. The results show that the radiation torque aligns the microspheroid along the nodal plane, and the radiation force causes a translational motion with a speed of up to one body length per second. Finally, the implications of this study on propelled nanorods by ultrasound are discussed.

中文翻译：

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理想圆柱室内球体颗粒的声辐射力和扭矩

在本文中，理论上研究了浸入在理想圆柱室内的非粘性流体中的小球形颗粒上的声辐射力和转矩。理想的腔室包括坚硬的顶部和底部（刚性边界条件）以及柔软的或坚硬的侧壁。通过假定粒子远小于声波波长，给出了由任意形状的声波引起的辐射力​​和转矩的解析表达式。与以前的结果不同，这些表达式是相对于固定的实验室框架给出的。展示了该模型，用于分析细长金属微球体（具有$10：\mathrm{1个}$长径比）在直径为几毫米的半波长声流体室内。结果表明，辐射扭矩使微球体沿着节点平面对齐，并且辐射力导致平移运动，速度高达每秒一个体长。最后，讨论了这项研究对超声推进的纳米棒的意义。