Finally finding that there are two reasons that cause vibration of pipe and noise . the one is the vibration of pump which transfers to pipe and stimulates the vibration of pipe . the second is the stimulating frequency of pulsating water is coherent with the natural frequency of pipe 最后得出管道的振动主要是由于两个原因，一是泵的机械振动传递给管道，引起管道的振动；二是由于水流的脉动激励频率与系统的固有频率相吻合，引起管道的共振发声。
