论文标题
毛细管中微粒的声学诱捕理论
Theory of acoustic trapping of microparticles in capillary tubes
论文作者
论文摘要
我们为毛细管内的粘性流体中的声场和颗粒捕获力提出了一种半分析理论，该理论具有任意横截面和墙壁的超声致动。我们发现，声场在长度尺度上与二维（2D）横截面谐振模式的质量因子的平方根成正比变化。该轴向变化是根据2D横截面中特征值问题的数值解决方案在分析上确定的。该分析分为两个步骤：首先，我们在矩形横截面中概括了2D站立波共振模式的最近发表的表达式，以任意形状，包括粘性边界层。其次，基于这些2D模式，我们在三个维度上得出分析表达式，以供声压，声辐射和捕获力以及声能通量密度。我们通过与三维数值模拟相比验证理论。
We present a semi-analytical theory for the acoustic fields and particle-trapping forces in a viscous fluid inside a capillary tube with arbitrary cross section and ultrasound actuation at the walls. We find that the acoustic fields vary axially on a length scale proportional to the square root of the quality factor of the two-dimensional (2D) cross-section resonance mode. This axial variation is determined analytically based on the numerical solution to the eigenvalue problem in the 2D cross section. The analysis is developed in two steps: First, we generalize a recently published expression for the 2D standing-wave resonance modes in a rectangular cross section to arbitrary shapes, including the viscous boundary layer. Second, based on these 2D modes, we derive analytical expressions in three dimensions for the acoustic pressure, the acoustic radiation and trapping force, as well as the acoustic energy flux density. We validate the theory by comparison to three-dimensional numerical simulations.
