Based on judging the different stages of cavitation through high-speed photography experiments, this paper presents a strategy for analyzing the variation in noise under different cavitation stages using the BEM method and Proudman theory. A multi-field synchronous test bench for marine pump hydraulic performance, flow noise, cavitation performance and cavity distribution is built. The critical cavitation numbers in different cavitation stages were determined by combining the cavitation performance curve and the morphology of the cavitation in high-speed photography. The research shows that with the development of cavitation, the rotor–stator interaction-induced noise is no longer the main noise source. The bubble will gradually block the flow passage and play a role in absorbing sound to reduce the area of the high sound power region. The sound pressure level of the blade passing frequency and its harmonic frequency gradually decreases. Under the action of the fan sound source, the drop in the 2BPF is the most obvious, and the maximum drop is 10%. The sound pressure level at the shaft frequency and the broadband total sound pressure level above 1000 Hz gradually increase, reach the maximum value under the developed cavitation stage. Cavitation-induced noise is broadband noise and its energy is concentrated in high frequencies.

中文翻译：

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船用离心泵不同汽蚀阶段噪声特性研究

在通过高速摄影实验判断空化的不同阶段的基础上，本文提出了一种利用边界元方法和Proudman理论分析不同空化阶段噪声变化的策略。搭建了船用泵水力性能、流动噪声、汽蚀性能和腔分布的多场同步试验台。结合高速摄影中的空化性能曲线和空化形态，确定不同空化阶段的临界空化数。研究表明，随着汽蚀的发展，转子-定子相互作用引起的噪声不再是主要的噪声源。气泡会逐渐堵塞流道，起到吸音的作用，减少高声功率区的面积。叶片通过频率及其谐波频率的声压级逐渐降低。在风扇声源的作用下，2BPF的下降最为明显，最大下降10%。轴频声压级和1000Hz以上宽带总声压级逐渐增大，在空化发展阶段达到最大值。空化引起的噪声是宽带噪声，其能量集中在高频。在空化阶段达到最大值。空化引起的噪声是宽带噪声，其能量集中在高频。在空化阶段达到最大值。空化引起的噪声是宽带噪声，其能量集中在高频。