Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814, USA.
J Acoust Soc Am. 2011 Apr;129(4):1679-80. doi: 10.1121/1.3560916.
This note concerns the evaluation of the static acoustic radiation torque exerted by an acoustic field on a scatterer immersed in a nonviscous fluid based on far-field scattering. The radiation torque is expressed as the integral of the time-averaged flux of angular momentum over a spherical surface far removed from the scattering object with its center at the centroid of the object. That result was given previously [G. Maidanik, J. Acoust. Soc. Am. 30, 620-623 (1956)]. Another expression given recently [Z. W. Fan et al., J. Acoust. Soc. Am. 124, 2727-2732 (2008)] is simplified to this formula. Comments are made on obtaining it directly from the general theorem of angular momentum conservation in the integral form.
这篇笔记关注的是基于远场散射，评估声场对浸入无粘性流体中的散射体施加的静态声辐射力矩。辐射力矩表示为远离散射物体的球形表面上的角动量通量的时间平均值在物体质心处的积分。该结果先前已经给出[G. Maidanik, J. Acoust. Soc. Am. 30, 620-623 (1956)]。最近给出的另一个表达式[Z. W. Fan 等人，J. Acoust. Soc. Am. 124, 2727-2732 (2008)]被简化为此公式。本文还对如何直接从角动量守恒的积分形式的一般定理得到该公式进行了评论。
