海水管路系统中流噪声的小室测量方法的研究

Study on Measuring Chamberlet Method of Flow Noise in Seawater Pipeline System

介绍了海水管路系统中流噪声的小室测量方法及其特点,分析了测量小室的声场特性及产生混响的下限频率。通过试验研究得出,当所测量的流噪声低于测量小室产生混响的下限频率,高于测量小室的第一阶共振频率时,测量小室会发生共振现象;在此测量频率段上,小室内各个空间点的变化规律基本相同,测量小室没有产生混响;对于低频流噪声的测量,可以将测量小室的几何尺寸做得较小,使其测量小室的第一阶简正频率大于所测量流噪声的最大频率,这样测得的声压幅值谱既没有共振峰,又可使低频流噪声的衰减较小。

This paper introduced a measuring chamberlet method and character for flow-noise in seawater pipe system and analyzed inferior-limited frequency of reverberation of measuring charaberlet. In our experiment it is found that resonance would take place in the measuring chamberlet when the measured flow-noise was lower than the inferior-limited frequency of produced reverberation and was high than first-step resonance frequency in measuring eharnberlet. At this measuring frequency the change rule of every space point in the chambrlet was basically the same. and the there was no reverberation in the chamberlet. For measuring the low frequency flow-noise, the geometric measurement of the chamberlet should be made little bit smaller so that the first-step normal frequency was bigger than the most frequency of measured flow-noise, in case the measured amplitude spectrum of round oressure has no resonance, and the low frequency flow-noise also would be reduced smaller.