标题： 压力声学理论与弯曲弹性腔体中的边界层和流动 显示英文标题

标题： Theory of pressure acoustics with boundary layers and streaming in curved elastic cavities

摘要： 声场和受限流体中的二次流强烈依赖于靠近壁面形成的声学边界层。 该层的宽度通常远小于由几何结构或声波波长决定的整体长度尺度，这使得直接数值模拟变得具有挑战性。 基于长度尺度的分离，我们通过推导一个考虑边界层效应的声压边界条件，扩展了经典的声压理论。 利用稳态二阶二次流的相同长度尺度分离，并结合一阶场的时均短程乘积，我们将通常的极限速度理论替换为在壁面上长程二次流场上的解析滑移速度条件。 所推导的边界条件适用于任意形状的振荡腔体以及壁面运动，只要壁面曲率和位移幅度都足够小。 最后，我们通过与两个二维水填充腔体的直接数值模拟进行比较来验证我们的理论：一个是已广泛研究的具有预定壁面激励的矩形腔体，另一个是嵌入外部激励的矩形弹性玻璃块中的更一般的椭圆形腔体。 显示英文摘要

摘要： The acoustic fields and streaming in a confined fluid depend strongly on the acoustic boundary layer forming near the wall. The width of this layer is typically much smaller than the bulk length scale set by the geometry or the acoustic wavelength, which makes direct numerical simulations challenging. Based on this separation in length scales, we extend the classical theory of pressure acoustics by deriving a boundary condition for the acoustic pressure that takes boundary-layer effects fully into account. Using the same length-scale separation for the steady second-order streaming, and combining it with time-averaged short-range products of first-order fields, we replace the usual limiting-velocity theory with an analytical slip-velocity condition on the long-range streaming field at the wall. The derived boundary conditions are valid for oscillating cavities of arbitrary shape and wall motion as long as the wall curvature and displacement amplitude are both sufficiently small. Finally, we validate our theory by comparison with direct numerical simulation in two examples of two-dimensional water-filled cavities: The well-studied rectangular cavity with prescribed wall actuation, and the more generic elliptical cavity embedded in an externally actuated rectangular elastic glass block.