【摘要】 利用数字声源信号可完全重复的特点,提出了通过单传声器对管道高次模式声波进行分解和测量的方法.阐述了此模式分解方法的基本原理,建立了相应的测试系统.通过试验测量,与传统的驻波管法相比较,验证了此方法的有效性.给出了一个典型的试验应用,对于口径为600mm的方形管道,在频率为500,1 000,2 000Hz时,对管中存在的高次模式声波进行测量和分解.此方法的特点是仅需要使用单个传声器进行测量,并提高了可分解的高次模式数量.更多还原

【Abstract】 The paper presents a new method for decomposing and measuring higher-order modes in ducts by single microphone.The method is based on a repeatable inspiriting sound source associated with a slowly moving microphone along central axis of the duct.At first,the basic principle of modal decomposition,as well as single-microphone measurement system,is described.Then the effectiveness of this method is verified by comparing the test results with those of the standard measurement in standing wave tube.Finally,some experimental studies in a 600 mm square duct are discussed.Only a single microphone is required,and much more higher-order modes can be decomposed.更多还原