Department of Mechanical Engineering, Facility for Research in Technical Acoustics, Indian Institute of Science, Bangalore-560012, India.
J Acoust Soc Am. 2010 Oct;128(4):1789-99. doi: 10.1121/1.3463801.
This paper describes an analytical calculation of break-out noise from a rectangular plenum with four flexible walls by incorporating three-dimensional effects along with the acoustical and structural wave coupling phenomena. The breakout noise from rectangular plenums is important and the coupling between acoustic waves within the plenum and structural waves in the flexible plenum walls plays a critical role in prediction of the transverse transmission loss. The first step in breakout noise prediction is to calculate the inside plenum pressure field and the normal flexible plenum wall vibration by using an impedance-mobility approach, which results in a compact matrix formulation. In the impedance-mobility compact matrix (IMCM) approach, it is presumed that the coupled response can be described in terms of finite sets of the uncoupled acoustic subsystem and the structural subsystem. The flexible walls of the plenum are modeled as an unfolded plate to calculate natural frequencies and mode shapes of the uncoupled structural subsystem. The second step is to calculate the radiated sound power from the flexible walls using Kirchhoff-Helmholtz (KH) integral formulation. Analytical results are validated with finite element and boundary element (FEM-BEM) numerical models.
本文通过考虑三维效应以及声学和结构波耦合现象，对带有四个柔性壁的矩形空腔的破裂噪声进行了分析计算。矩形空腔的破裂噪声很重要，并且在预测横向传输损耗时，空腔内的声波与柔性空腔壁中的结构波之间的耦合起着关键作用。破裂噪声预测的第一步是使用阻抗-导纳法计算内部空腔压力场和正常的柔性空腔壁振动，这导致了紧凑矩阵公式的产生。在阻抗-导纳紧凑矩阵（IMCM）方法中，假定可以用有限的不耦合声学子系统和结构子系统的集合来描述耦合响应。空腔的柔性壁被建模为一个展开的板，以计算不耦合结构子系统的固有频率和模态形状。第二步是使用 Kirchhoff-Helmholtz (KH) 积分公式计算从柔性壁辐射的声功率。通过有限元和边界元（FEM-BEM）数值模型对分析结果进行了验证。
