A general formalism for acoustic 2-port source with multi-propagating modes in duct

Abstract

就管道通风系统而言,在研究其中的声场分布和同管道末端负载的相互作用影响时,对作为噪声源的流体风机的特征描述是一个关键环节。已往的一些研究往往采用基于管道中平面声波传播的一端或二端模型。而在很多实用场合,由于声源耦合入管道中的声波频率较高,需要考虑所激发出的高阶声场模态。文中提出了一种新的方法,用来在二端耦合的管道中存在高阶声波模态传播的情况下,测量描述这类稳态声源特征。 The source characterization of fluid machines is important for calculating the acoustic field generated in duct systems and for the analysis of source-load interaction effects. Several investigators used one-or two-port model to describe fluid machines as acoustic sources and the study is only limited to the plane wave region. However,for some applications it is necessary to characterize them at frequencies beyond this region since higher order modes can propagate along the ducts coupled to the machine. In the present work,a measurement method is suggested for a linear time-invariant source with two active openings connected to a duct where multi-propagating modes exist. 还原