中文摘要：

针对两级离心泵瞬态空化流动及压力脉动特性,基于全空化和混合两相流模型,采用RNG k-ε方法对某两级离心泵内空化流动进行数值计算,获得了叶轮内空泡分布情况及压力脉动频谱特性曲线。结果表明;随着进口压力的降低,空化区域不断扩展,空化气体体积百分比在接近临界空化点处达到最大。由于叶轮与导叶之间的正对干涉,第一级叶轮流道内各个测点压力脉动的主导频率为15倍基频。可能由于级间干涉,使得蜗壳中截面测点压力脉动的主导频率为叶频的偶数倍频;随着进口压力的降低,隔舌附近测点压力脉动幅值逐渐增加,在临界空化点附近达到极大值。

英文摘要：

The research was conducted for the purpose of studying transient cavitation flow and pressure fluctuation in a two stage centrifugal pump. The whole cavitation flow was simulated based on full cavitation model and mixed two-phase flow model, using RNG k - ε method. The characteristics of vapor distribution and spectrum curve of pressure fluctuation were achieved. The results show that the area of cavitation expanding and the gas volume fraction was maximizing on cavitation critical point with the reduction of inlet total pressure. The dominant frequency of pressure fluctuation in the first impeller was about 15 times of the rotating frequency because of the interference between the leaves and the guide vanes. The dominant frequency of pressure fluctuation on the volute was even number times of the blade passing frequency because of the interference between stages. The pressure fluctuation near the tongue of volute was increasing and maximizing on cavitation critical point with the reduction of inlet total pressure.