无后置导叶轴流泵瞬态空化流场的数值分析

A Numerical Analysis of Transient Cavitation Flow Field in Axial Flow Pump Without Post-Set Guide Blade

为了深入研究TZX-700型无后置导叶轴流泵内部瞬态空化流场的压力脉动情况,通过ANSYS CFX软件,采用SST湍流模型和Rayleigh-Plesset空化模型,对TZX-700型无后置导叶轴流泵压力脉动进行了瞬态空化流场的数值计算研究。主要计算了该无后置导叶轴流泵在3个不同流量工况(0.9Qd、1.0Qd、1.1Qd)下瞬态空化流场的压力脉动情况,分析了轴流泵在设计工况下随叶轮旋转时间的周期性变化叶片表面空化体积分数的分布情况及不同工况下叶轮进、出口截面不同监测点下的瞬态空化流下压力脉动的时域图和频域图。通过数值计算的结果表明:在一个叶轮旋转周期内相较于其他的工况,该无后置导叶轴流泵的空化流场在设计工况下一般是稳定的;叶轮压力周期性脉动在叶轮的各个监测点处随叶轮旋转时间的变化呈现出周期性变化规律,轴流泵叶轮压力脉动的频率主要集中在叶轮转频及其谐波频率。

In order to study the pressure pulsation transient cavitation flow field inside the TZX-700 axial flow pump without rear vane deeply,this paper uses ANSYS CFX software,based on the SST turbulence model and Rayleigh-Plesset homogeneous flow cavitation model.The pressure pulsation of TZX-700 axial flow pump without rear guide vanes is studied by numerical calculation of transient pressure pulsation cavitation flow field.This paper mainly calculates the transient pressure pulsation cavitation flow field of the axial flow pump without rear guide vane under three different flow conditions(0.9Qd,1.0Qd,1.1Qd),and analyzes the design of the axial flow pump in the design,the time-domain and frequency-domain diagrams of the pressure fluctuations of the cavitation volume fraction on the surface of the lower impeller with the impulse rotation time and the pressure fluctuations of the transient cavitation flow at different monitoring points of the impeller inlet and outlet sections under different operating conditions.The results of numerical calculations show that the cavitation flow field of the axial flow pump without rear guide vane is generally stable under the design conditions compared with other conditions during one impeller rotation period;the impeller pressure pulsates periodically.At each monitoring point of the impeller,the pressure periodically changes with the impeller rotation time.The frequency of the periodic impulse pressure of the impeller without a rear guide vane is mainly concentrated on the impeller rotation frequency and its harmonic frequency.