空间导叶式离心泵非定常流动压力脉动特性分析

Pressure Fluctuation Analysis of Unsteady Flow in Centrifugal Pump with Space Guide Vane

为研究立式长轴泵叶轮与空间导叶间由于动静干涉诱发泵流场内的压力脉动特性,基于标准κ-ε模型及Reynolds时均N-S方程对某型号立式长轴泵水力模型在0.8Q、1.0Q、1.2Q三种工况下进行非定常数值模拟,得到各监测点的压力脉动时域数据,通过FFT变换得到频域图谱,并对时域、频域曲线进行分析。结果表明,叶轮与空间导叶的动静耦合作用是产生压力脉动的主因;泵中主要存在白噪声、叶频及转频三种形式的压力脉动;压力脉动的大小受工况影响较大,额定工况下压力脉动值较小。研究结果为空间导叶式离心泵水力性能优化、振动及噪声诊断提供了依据,对其他形式压水室水压力脉动研究也有参考价值。

To study the pressure fluctuation phenomenon induced by impeller-guide vane interaction between pump impeller and space guide vane,an unsteady numerical simulation for a certain type of vertical long-axis pump hydraulic model was performed at operating conditions of 0.8Q,1.0Qand 1.2Qbased on Standardκ-εmodel and Reynolds-averaged Navier-Stokes equations.The time-domain pressure fluctuation of each monitoring point was obtained and it was transformed into frequency-domain spectrum by FFT.According to the characteristic curve and numerical results,it concludes that the impeller-guide vane interaction is the main cause of pressure fluctuation in vertical long-axis pump.There are three kinds of pressure fluctuations,namely random fluctuation,blade-passing frequency fluctuation and rotational frequency fluctuation.The fluctuation amplitude is significantly influenced by operating conditions.Minimum fluctuation amplitude was appeared on the rated condition.Therefore,the research provides a basis for centrifugal pump hydraulic performance optimization,vibration and noise diagnosis,and it also has reference value for further studies on pressure fluctuation of other kinds of pumping chamber.