不同叶片数对离心泵流场诱导振动的影响

为了研究离心泵不同叶片数对振动的影响,在保证泵体和叶轮几何参数不变的情况下,将叶轮叶片数分别设计为6和7,从试验与数值计算2个方面就叶片数对离心泵流场诱导振动进行研究.采用RNG k-ε模型分别对2种叶片数的离心泵进行全流道稳态及非稳态数值模拟,分别获得2种叶片数离心泵的稳态速度、压力及非稳态压力脉动特性,对其进行对比分析,并试验测量了2种叶片数下模型泵机脚的振动信号,对振动信号数据进行了处理,从而验证数值计算结果的正确性及改变叶片数所产生的振动影响.结果表明：6叶片的叶轮及蜗室内各个监测点压力脉动较小,机脚振动在轴频下响应较小;叶片数为7时,轴频的二倍频与叶频的低倍频峰值变大,而叶频的高倍频幅值有所降低.结果对建立低振动低噪声离心泵水力设计方法具有重要的参考意义和指导作用.

Impact of blade number on fluid-induced vibration in centrifugal pump

In order to study impact of blade number on fluid-induced vibration in centrifugal pumps, the impellers of a centrifugal pump were designed with 6 and 7 blades while the rest geometry remains unchanged, the fluid induced vibration in the pump was investigated by experiment and simulation simultaneously. Firstly, the RNG κ-ε turbulence model was used to simulate the steady and unsteady flow in the two configurations; secondly, the steady velocity and pressure, and unsteady pressure fluc- tuations were obtained and analyzed. Finally, the vibration signals at pump feet were measured and processed to validate the simulated results and the effect of blade number. The results showed that the pressure pulsation at monitoring points in the impeller and volute with 6 blades was less than that with 7 blades, and the vibration response at the feet under shaft rotational frequency was also smaller. For the impeller with 7 blades, the peak value at two times the shaft rotational frequency and the blade passing frequency became larger; while the amplitude at the frequency larger than the blade passing frequency was decreased. These results can be instructive for design of a centrifugal pump with low vibration and noise.