核主泵空化过渡过程水动力特性研究

采用流场分析软件ANSYS CFX对核主泵在不同空化工况下的水动力特性进行数值模拟分析，利用Morlet小波变换和快速傅里叶变换对相应数据进行处理分析。结果表明：气体含量随压力的降低或时间的增加呈现出指数变化规律。在空化初生工况，核主泵扬程脉动频率以低频为主，叶轮流道内的压力脉动的主频仍以转频为主，而空化产生的压力脉动对主频的影响不明显。随着空化的发展，空化所诱发的压力脉动对主频、次主频及脉动幅值的影响越来越大，其扬程脉动频率以低频脉动为主。空化严重工况时，扬程脉动频率以无规律变化的脉动高频为主，同时包含近乎规律变化的脉动低频。

Analysis on Transient Hydrodynamic Characteristics of Cavitation Process for Reactor Coolant Pump

The reactor coolant pump hydrodynamic characteristics at different cavitation conditions were studied by using flow field analysis software ANSYS CFX, and the corresponding data were processed and analyzed by using Morlet wavelet transform and fast Fourier transform. The results show that gas content presents the law of exponential function with the pressure reduction or time increase. In the cavitation primary condition, the pulsation frequency of head for the reactor coolant pump is mainly low frequency, and the main frequency of pressure pulsation is still rotation frequency while the effect of the pressure pulsation caused by cavitation on main frequency is not obvious. With the development of cavitation, the pressure fluctuation induced by cavitation becomes more serious especially for the main frequency, secondary frequency and pulsating amplitude while the head pulsation frequency is given priority to low frequency pulse. Under serious cavitation condition, the head pulsation frequency is given priority to irregular changes of pulse high frequency, and also contains almost regular changes of low frequency.