【摘要】 本文建立了管道单极有源降噪系统的数学模型,在此基础上建立了两个管道单极有源降噪系统,分别称之为NCMS 系统和LFAM 系统。两个系统各具特点,分别适用于探测传声器的指向性因子α不同时的场合。NCMS 系统用补偿的方法对次级源的声反馈和系统组件的非理想相移特性进行了双重补偿。LFAM 系统通过改善探测传声器的工作指向性,使系统结构十分简单。两个系统都取得了良好的降噪效果,并实现了气流条件下的宽带降噪。更多还原

【Abstract】 This paper builds the mathematical model of a monopole system for the activeattenuation of noise in ducts.Based on the theoretical analysis,two kinds ofmonopole systems,LFAM and NCMS,for the active attenuation of noise in ductsare built.Both systems have their own characteristics and are individually suitblefor different situations where the directional coefficient a of detector Microphonesis different.The NCMS system compensates both the influence of secondary sourceacoustic feedback and the non-ideal phase property of the components.The LFAMsystem makes the structure of the monopole system very simple Both systems givegood attenuation results,and realize wide band attenuation in the condition of airflowing in ducts.更多还原