气流管道有源消声器声学性能分析

结合噪声源和管道末端的阻抗特性，以及管道中的声传播特性，使用电声类比和传递矩阵技术，建立了气流管道有源消声器声学性能分析的理论模型。文中对管道有源消声器的传递损失和插入损失进行了计算，结果表明，有源消声器的实际消声性能与管内气流马赫数、检测传声器相对于次级声源的位置、控制系统的频响，以及噪声源和管道末端的阻抗特性密切相关。

ANALYSIS OF ACOUSTICAL PERFORMANCE OF ACTIVE NOISE ATTENUATORS IN FLOW DUCT

Active noise control has ben the subject of considerable research in recentyears.A large portion of this work haS been directed toward the active control of noise inducts, partly because Of potental widespread industrial applications, and partly because working experimentai systems can be built readily.However,no analytical model has been developed that edequately predicts the acoustical performance of active noise attenuator in duct. Inthis paper,a model for predictal and analyzing acoustical performance of active noise attenuator in flow duct is deVelOPed by incorporating the charederistics of noise source and terminationimpedance,as well as the sound propagation in duct,and making use of the electroacousticanalogies and transfer matrix techniques.The four-pole parameters for actiVe noise attenuator in flow duct are also presented,and the acoustical performance such as transmission lossand insertion foes can be predicted.The transmission losses of actiVe noiSe attenuators in flowduct with monopole and unidirectiond secondary source are calculated,and the results demonstrate that the flow Mach number in duct,the detector microphone location with respect tosecondary source,and the resPOnse of eledronic control system affeCt greatly the transmissionlOSs performance.The insertion lodes of active noise attenuator in flow duct with monopolesecondary source are also Predicted for three source impedance (constant velocity source,COnstant pressure source and non-reflecting source) and two duct termination (non-reflectingand opening) models,and the results demonstrate the dependance of acnievable noise attenuation on the characteristics of noise source and termination impedance.The presented analyticalmodel is not only suitable for monopole the dial secondals source arrangemens, but can be extended easily to any number of secondary sources.