【作者】 梁金栋；

【导师】 储训；

【作者基本信息】 扬州大学 ， 流体机械及工程， 2005， 硕士

【摘要】 随着我国国民经济的发展,南水北调工程的开工,一大批大、中型水泵机组将投入长期运行,其安全可靠性尤为重要。因此,安全可靠性已越来越成为大、中型水泵机组的重要指标。影响水泵机组工作安全可靠性的因素很多,汽蚀是其中的重要因素之一。 水泵汽蚀问题,从20世纪至今,一直是水力机械科学的一项重要研究课题,世界各国做了大量的研究工作。在泵运行过程中,若在汽蚀的初生阶段就能及时发现汽蚀现象,则可以采取一些有效措施,以减少汽蚀对泵的冲蚀破坏,延长泵的使用寿命。 本文主要针对汽蚀初生的噪声和超声波特性,从理论和实验两方面作了探讨性研究。其中实验包括试验方案的确定、信号的采集、信号的分析几个方面。在信号分析过程中,从信号除噪、幅域分析、频域分析、小波分析、小波包分析、信号重构几方面着手,得出了汽蚀初生时空化噪声强度、频率分布等方面的规律。更多还原

【Abstract】 Along with the start of south-to-north water diversion project, there will be a number of large and middle pumping stations to be in long-term service, of which security is more important. Therefore, security has been the index to value the large and middle pumping stations. There are many factors which can influence large and middle pumping stations’ security, in which cavitation is one of the most important.From the 20 centuries, cavitation was always the important research problem in hydraulic mechanism science. To solve it, researchers worldwide have done large numbers of work. If cavitation can be detected in its early period during the pumping stations works, effective measures can be taken to reduce the cavitation breakage and prolong the life-span of pumping stations.This dissertation mostly researches the noisy and ultrasonic characteristic from theory and experimental ways when cavitation occurs early. The experiment includes the choice of experimental scheme、 the collecting and processing of signal, etc. Through wiping off noise from signal、 time domain and frequency domain analysis、 wavelet analysis、 wavelet package analysis, the law of cavitation noise intension and frequency distributing are found.更多还原